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Zhang, Xiangcheng. "Fracture of modified urethane-methacrylate resins." Thesis, Cranfield University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358297.
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Munshi, Imran. "Reaction-induced phase separation in modified epoxy resins." Thesis, University of Manchester, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493906.
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Studies have been carried out on reaction-induced phase separation in epoxy networks, formed from a DGEBA-type epoxy resin prepolymer, DER332, and m-xylylene diamine, MXDA, containing as modifiers either (i) butyl laurate (B) or (ii) m-cardura (C), (synthesised from Cardura El0 and 2-ethyUiexanoic acid). The reactants and modifiers were characterised using end-group analysis, Fourier transform infra-red spectroscopy (FTIR), differential scanning calorimetry (DSC), nuclear magnetic resonance and viscometry.
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Karad, Sunil. "Moisture sensitivity of cyanate ester modified epoxy resins." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286617.
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Wang, Guigui. "Perfluorotriethylene glycol dimethacrylate modified composite resins for improved dental restoratives." The Ohio State University, 1998. http://catalog.hathitrust.org/api/volumes/oclc/47350511.html.
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Roberts, Karen Narelle 1972. "An investigation of core-shell rubber modified vinyl ester resins." Monash University, School of Physics and Materials Engineering, 2002. http://arrow.monash.edu.au/hdl/1959.1/8416.
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Xie, Dong. "N-vinylpyrrolidone modified glass-ionomer resins for improved dental restoratives." The Ohio State University, 1998. http://catalog.hathitrust.org/api/volumes/oclc/47196478.html.
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Wu, Jiawei. "Study on Epoxidized Poly (Styrene-butadiene-styrene) Modified Epoxy Resins." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1571671436341218.
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Thitipoomdeja, Somkiat. "Factors influencing the properties of epoxy resins for composite applications." Thesis, Loughborough University, 1995. https://dspace.lboro.ac.uk/2134/10852.
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The aim of the work reported here was to determine the influence of an amine curing agent, and postcure cycle on the mechanical and thermal properties of diglycidyl ether of bisphenol A (DGEBA) epoxy resin. The results of this initial study were then used as the basis for selecting material to obtain optimum toughness in epoxy/glass fibre systems. These basic materials were further used to make comparisons with the properties of modified resin systems which contained commercial elastomers. Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA), Fourier Transform Infrared Spectroscopy (FTIR), flexural and interlaminar shear tests, Instrumented Falling Weight Impact (IFWI), visual observation, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were all used to investigate various properties and the structures which gave rise to them. The properties of cured products were found to be affected by the amounts of curing agent, curing times and temperatures, and the structure of the elastomers. Not surprisingly the maximum thermal and mechanical properties tended to be found in the stoichiometric (standard) mix systems. However, postcuring at higher than room temperature, which was used as the basic curing temperature, led to more conversion. This effect improved the thermal and mechanical properties of both the unmodified and modified resin systems. The maximum flexural strength of 104 MPa of the unreinforced resins was found in the stoichiometric mix ratio after postcure at 150°C for 4 hr. However, the maximum flexural modulus and glass transition temperature (Tg) were found after postcuring at the same temperature for 48 hr. This was believed to be due to increased crosslinking, but unfortunately the longer curing time led to degradation of the resins. In the systems modified with -20 phr of polyetheramine elastomers, the one modified with the lowest molecular weight (2000) was found to have the highest flexural strength (85.8 MPa) and modulus (2.5 GPa). The impact properties of all the composites with modified resin matrices were found to be higher than the unmodified resin matrix composites. The best impact properties were, however, obtained with the elastomer modifier with a molecular weight of 4000. The impact energy at maximum force increased from 11.9 to 16.4 J, and energy at failure increased from 18.7 to 21.6 J. This increase in impact properties was due to the increase in areas of phase separated elastomer particles over similar systems with lower molecular weight modifier.
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Lee, W. H. "Elastomer modified epoxies : Toughening of tetraglycidyl diamino diphenyl methane epoxy." Thesis, Brunel University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234017.
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El-Turabi, Mohammed El Hassan. "The reactions of cellulose and modified cellulose with amide/formaldehyde resins." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329190.
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Siu, Wing Kwan May 1979. "Applications and microwave assisted synthesis of poly(ethylene glycol) modified Merrifield resins." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82427.
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A microwave assisted methodology was developed to modify Merrifield resins (1-2% cross-linked containing 1.0-3.5 mmol Cl-/g) with different nominal molecular weights PEG (200-1000). The synthesis was also carried out by conventional heating to assess the differences between the two procedures. The most efficient synthesis was achieved by using microwave and by using PEG with molecular weight 200 and MR 2% crosslinked containing 1.25 mmol Cl -/g. The structural elucidation was carried out using Fourier transform infrared (FTIR) spectroscopy and elemental analyses. Upon pyrolsis-GC/MS analysis of the PEGylated MR, the PEG showed the tendency to undergo thermal degradation by the loss of a smaller PEG fragments. This observed degradation of PEG was less prominent during microwave assisted synthesis compared to conventional heating, in addition to faster reaction rates and higher yields. As expected, the PEGylated MR showed improved swelling properties in polar solvents. The chemical reactivity of the PEGylated Merrifield resin was confirmed by the esterification with pyruvic acid and by the substitution of hydroxyl group using thionyl chloride. In addition, the PEGylated MR was converted into (1) polymer-supported acid/base or redox indicator by the attachment of a blue organic dye - 2,6-dichloroindophenol (DCIP) through a nucleophilic substitution reaction and (2) beta-cyclodextrin trap, a water insoluble inclusion-complex, by immobilization of beta-cyclodextrin through cross-linking with 1,6-hexamethylene diisocyanate reagent.
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Kim, Young Eun. "Modified Phenol-Formaldehyde Resins for C-Fiber Reinforced Composites: Chemical Characteristics of Resins, Microstructure and Mechanical Properties of their Composites." Doctoral thesis, Universitätsbibliothek Chemnitz, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-64064.
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This work correlates the chemistry of phenol-formaldehyde (PF) resins, its functionalities with their microstructural and mechanical properties in composite materials. The main focus is put on the development of the pores in dependence on the chemical composition of the resins and their influence on the structure of the material.
Chemical characteristics of the synthesized resins are analyzed and physical/mechanical properties of the matrices based on PF resins are determined. Differences in the chemical properties are detected e.g. by FT-IR and NMR spectroscopy. They indicate the existence of similar molecular basic structure units, but different network conditions of the resins. DSC investigations point on different reaction mechanisms and temperatures; they reveal also their changed thermal behavior. The bulk matrix behavior differs from that of the composite based on the same resin due to the three dimensional stress and strain fields in the composites. The structure of the CFRP composites is strongly depended on the fiber/matrix interaction. The fiber matrix bonding (FMB) strength controls the load transfer via shear forces and therefore the segmentation of the fiber bundles.
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Hse, Mei-yin Kitty, and 許美賢. "Clinical evaluation of compomer, a polyacid-modified composite resin, in primary teeth: 1 year results." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31954029.
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Hse, Mei-yin Kitty. "Clinical evaluation of compomer, a polyacid-modified composite resin, in primary teeth 1 year results /." Hong Kong : Faculty of Dentistry, The University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19902232.
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Phillips, M. J. "Composistion-morphology-mechanical property effects and the antishrink mechanism in low profile modified unsaturated polyester thermosetting resins." Thesis, Cranfield University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305379.
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Luo, Yan, and 羅琰. "Assessment of a glass polyalkenoate cement and a polyacid-modified resin composite for the restoration of posterior teeth." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31242121.
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Luo, Yan. "Assessment of a glass polyalkenoate cement and a polyacid-modified resin composite for the restoration of posterior teeth." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22242879.
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Sousa, Maria de Fatima Alves de. "Influencia de sistemas adesivos na penetração e infiltração marginal de materiais resinosos empregados no selamento de fossas e fissuras oclusais." [s.n.], 1998. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288597.
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Orientadores: Regina Maria Puppin Rontani, Mario Fernando de Goes<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba<br>Made available in DSpace on 2018-07-24T01:23:45Z (GMT). No. of bitstreams: 1
Sousa_MariadeFatimaAlvesde_M.pdf: 3394004 bytes, checksum: eb6d811292eb170c25158510f6fe88e1 (MD5)
Previous issue date: 1998<br>Resumo: A efetividade e sucesso clínico dos sei antes dependem da sua retenção na superfície oclusal. Este estudo avaliou a penetração do selante FluroShield (Dentsply) e do compômero Compoglass (Vivadent) e a infiltração do corante fucsina básica na interface esmalte/material. Foram selecionados 64 pré-molares hígidos, distribuídos em 8 grupos, dos quais 4 foram submetidos à técnica convencional (TC) e os outros à técnica Invasiva (TI). Os tratamentos realizados foram: grupo 1- TC e aplicação do Compoglass; grupo 2- TI e aplicação do Compoglass; grupo 3- TC, agente adesivo SCA e Compoglass; grupo 4- TI, agente adesivo SCA e Compoglass; grupo 5- TC e aplicação do FluroShield; grupo 6- TI e aplicação do FluroShield; grupo 7- TC, primer/adesivo PSA e FluroShield; grupo 8- TI, primer/adesivo PSA e FluroShield. Em seguida, os dentes foram submetidos a 500 ciclos térmicos, em banhos alternados de 5 o e 60°c e a seguir imersos em uma solução de fucsina básica a 0,5% por 24 horas. Os dentes foram seccionados no sentido vestíbulo-lingual, polidos e as superfícies observadas em um microscópio óptico, sendo as imagens processadas em um computador através do software (Diracom3). Os valores dos percentuais de penetração dos materiais foram submetidos à análise de variância e ao teste de Tukey (p< 0,05). O material Compoglass aplicado pela técnica convencional, sem o uso de adesivo apresentou média de penetração inferior aos demais tratamentos, sendo a diferença entre as médias estatisticamente significativa. O material FluroShield apresentou médias de penetração semelhantes quando aplicado por ambas as técnicas convencional e invasiva, com ou sem a prévia aplicação de adesivo (p>0,05). A ocorrência de infiltração para as amostras tratadas com Compoglass sem adesivo foi estatisticamente superior ao mesmo material aplicado com adesivo pelo Teste exato de Fisher (p<0,05). Entre as técnicas convencional e invasiva não houve diferenças estatisticamente significativas ao nível de 5%, na ocorrência de infiltração, tanto para Compoglass quanto para FluroShield, pelo teste exato de Fisher. FluroShield aplicado sem adesivo apresentou os menores percentuais de amostras com infiltração quando comparado com o mesmo material associado ao uso de adesivo. Conclui-se que, os maiores percentuais de penetração e os menores percentuais de infiltração foram encontrados para o material FluroShield aplicado sem o adesivo. Para o material Compoglass os maiores percentuais de penetração e menores percentuais de infiltração foram encontrados quando associado ao emprego de adesivo<br>Abstract: The sealants effectiveness and clinical success depend on retention and reduction of the occlusal caries. This study evaluated the penetration and the microleakage of the FluroShield Sealant (Dentsply) and the Compoglass compomer (Vivadent). Sixty-four premolars, noncarious were used and they were divided into eight groups. Four groups were submitted to Enameloplasty Sealant Technique (EST) and the other one to Conventional Sealant Technique (CST). The group 1: CST and applied Compoglass; group 2: EST and applied Compoglass; group 3: CST, primer SCA and Compoglass; group 4: EST, primer SCA and Compoglass; group 5: CST and applied FluroShield; group 6: EST and applied and Fluroshield; group 7: CST, primer PSA and FluroShield; grupo 8: EST, primer PSA and FluroShield. After that, the teeth were termocycled 500x at temperature 5° and 60°C, and imersed in a 0.5% solution basic fuchsin dye for 24 hours. The teeth were sectioned in a bucal-lingual direction, and they were polished. The surfaces were evaluated on the optical microscope. The images were captured into the computer (Diracom3 System). The percentage data of the penetration of both materiais were submitted to variance analyses and Tukey's Test (p<0.05). The penetration data from the Compoglass samples with no adhesive used by the conventional sealant technique were significantly lower than the other groups (p<0.05). The penetration means those were obtained with the use of FluroShield for both techniques, conventional and invasive, did not show significant differences statistically (p>0.05). Compoglass applied without adhesive showed more leakage percentages than the same material applied with adhesive. FluroShield no adhesive showed lower leakage percentages than the same material used with adhesive. FluroShield used no adhesive and Compoglass used with adhesive provided the highest percentage of penetration and the lowest leakage<br>Mestrado<br>Materiais Dentarios<br>Mestre em Odontologia
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Bilyeu, Bryan. "Characterization of Cure Kinetics and Physical Properties of a High Performance, Glass Fiber-Reinforced Epoxy Prepreg and a Novel Fluorine-Modified, Amine-Cured Commercial Epoxy." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4437/.
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Kinetic equation parameters for the curing reaction of a commercial glass fiber reinforced high performance epoxy prepreg composed of the tetrafunctional epoxy tetraglycidyl 4,4-diaminodiphenyl methane (TGDDM), the tetrafunctional amine curing agent 4,4'-diaminodiphenylsulfone (DDS) and an ionic initiator/accelerator, are determined by various thermal analysis techniques and the results compared. The reaction is monitored by heat generated determined by differential scanning calorimetry (DSC) and by high speed DSC when the reaction rate is high. The changes in physical properties indicating increasing conversion are followed by shifts in glass transition temperature determined by DSC, temperature-modulated DSC (TMDSC), step scan DSC and high speed DSC, thermomechanical (TMA) and dynamic mechanical (DMA) analysis and thermally stimulated depolarization (TSD). Changes in viscosity, also indicative of degree of conversion, are monitored by DMA. Thermal stability as a function of degree of cure is monitored by thermogravimetric analysis (TGA). The parameters of the general kinetic equations, including activation energy and rate constant, are explained and used to compare results of various techniques. The utilities of the kinetic descriptions are demonstrated in the construction of a useful time-temperature-transformation (TTT) diagram and a continuous heating transformation (CHT) diagram for rapid determination of processing parameters in the processing of prepregs. Shrinkage due to both resin consolidation and fiber rearrangement is measured as the linear expansion of the piston on a quartz dilatometry cell using TMA. The shrinkage of prepregs was determined to depend on the curing temperature, pressure applied and the fiber orientation. Chemical modification of an epoxy was done by mixing a fluorinated aromatic amine (aniline) with a standard aliphatic amine as a curing agent for a commercial Diglycidylether of Bisphenol-A (DGEBA) epoxy. The resulting cured network was tested for wear resistance using tribological techniques. Of the six anilines, 3-fluoroaniline and 4-fluoroaniline were determined to have lower wear than the unmodified epoxy, while the others showed much higher wear rates.
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Tchatchoua, Ngassa. "Synthesis and Characterization of Phosphine Oxide Containing Monomers and of the Flame Resistant Polymers Prepared Therefrom." Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/37676.
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This thesis has focused on the synthesis and characterization of amino functional monomers, principally monomers containing aryl phosphine oxide units. Utilization of these monomers was demonstrated in various types of linear and network polymerizations. The diamines monomers included bis(3-aminophenyl) methyl phosphine oxide (DAMPO), bis(3-aminophenyl) phenyl phosphine oxide (DAPPO), bis(3-aminophenoxy phenyl) phenyl phosphine oxide (BAPPO) and bis(3-aminophenoxy phenyl) methyl Phosphine oxide (BAMPO). From these monomers high molecular weight poly(ether imides), polyurea-urethanes, poly(arylene ether ketones) poly(arylene ether sulfones) and poly(arylene ether phosphine oxides) were. Internal and external fire testing methodologies showed that the new polymers containing phosphine oxide units were fire resistant while maintaining the desirable physical characteristics of carefully selected control systems.
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In addition, suitable curing schedules for epoxy networks were determined by using dielectric monitoring techniques. The curing rates varied with the structure of the monomers and were slowest for the deactivated control (4,4'aminophenyl sulfone). Epoxy networks containing aryl phosphine oxide units had higher char yields in dynamic thermogravimetric analyses than control specimens. This correlated with their superior flame resistance.
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The brittle epoxy matrices were subsequently modified with reactive or non-reactive thermoplastic polymers in order to improve their fracture toughness. Poly(ether imides) and poly(ether sulfones) showed good phase separation behavior with tetrafunctional epoxy matrices during the curing reactions, as confirmed by scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA). Mechanical tests showed that reactive thermoplastic modification of the epoxy networks improved the fracture toughness of the systems, without noticeable decreases in other characteristics such as flexural modulus. Reactive systems also maintained chemical resistance in contrast to non-reactive thermoplastic controls.<br>Ph. D.
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Aquino, Eugene Canlas. "The Effects of the Exposure of Atomic Oxygen on Polymeric Material: I Siloxane Modified Epoxy Resins II Polyetherimide Films with Additives." W&M ScholarWorks, 1991. https://scholarworks.wm.edu/etd/1539625668.
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Kim, Young-Eun [Verfasser]. "Modified phenol formaldehyde resins for C-fiber reinforced composites : chemical characteristics of resin, microstructure and mechanical properties of their composites / Kim, Young Eun. [Technische Universität Chemnitz, Institut für Werkstoffwissenschaft und Werkstofftechnik]." Chemnitz : IWW, 2010. http://d-nb.info/1011885034/34.
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Yalala, Bongani Ndhlovu. "Ion exchange resins an functional fibres :a comparative study for the treatment of brine waste water." Thesis, University of the Western Cape, 2009. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8342_1298358875.
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<p>To improve the adsorption capacity of polyacrylonitrile (PAN) fibres, hydrophilic amidoxime fibres were prepared by subsequent conversion of the cyano groups to an amidoxime group by reacting with hydroxylamine at 80°<br>C at an optimum amidoximation time of 2 hrs. The amidoxime fibre was hydrolyzed/alkali treated in a solution of sodium hydroxide to enhance or improve the adsorption properties. This was followed by characterization of the amidoxime and hydrolyzed fibres using Scanning electron microscopy (SEM)<br>Fourier transform Infrared Spectroscopy (FTIR) and exchange capacity (cationic and anionic). SEM showed that the hydrolysis process made the surface of Amidoxime fibre rougher than that of Polyacrylonitrile fibre. FTIR revealed that the hydrolyzed Amidoxime fibres contained conjugated imine (-C=N-) sequences. Functionalization enhanced the sorption of amidoxime fibres by an increase of 20 % in the cationic exchange capacity. This was achieved by the part conversion of the cyano groups into the carboxylic acid groups. The fibres showed faster kinetics largely due the available exchange sites on the surface of the fibres hence the equilibration was achieved much quicker.</p>
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Koutsikas, Peter. "The influence of porosity levels on shear strength and water movement in a resin-modified glass ionomer restorative cement (Fuju II LC Improved) : thesis submitted for the degree of Master of science in Dentistry, Dental School, Faculty of Health Sciences, the University of Adelaide /." Title page, table of contents and abstract only, 2004. http://web4.library.adelaide.edu.au/theses/09DSM/09dsmk882.pdf.
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Avila, Gisseli Bertozzi de. "Resina industrial de poliuretano modificada com terra diatomácea para ser empregada na modelagem odontológica." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/58/58131/tde-26032010-124102/.
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Este estudo avaliou a resina de poliuretano de alto desempenho 6470 e endurecedor Dt 082 (Huntsman Advanced Materials Química Brasil Ltda., fornecido pela Maxepoxi, Santo Amaro, São Paulo, Brasil) carregada com 30 % diatomita para ser empregada na modelagem odontológica. O material foi manipulado na proporção de 1/8 entre resina e endurecedor, com acréscimo de acelerador de poliuretano na proporção de uma gota para cada 200gramas de resina. Foram obtidas amostras de resina pura, modificada com diatomita e gesso tipo IV(Fuji Rock EP), GC America Inc-USA para os ensaios de resistência a compressão e tração por compressão diametral ASTM D 695 2(a), resistência a fratura por impacto ISO 179-1: 2000., resistência a flexão três pontos (ISO 1567:1999), resistência ao desgaste por abrasão norma ASTM D 4060. Amostras foram analisadas quanto ao comportamento dimensional em um projetor de perfil (Mitutoyo PJ-A3000 Japão), a rugosidade superficial Ra, e capacidade de copia de detalhes foram analisadas em Rugosímetro (Mitutoyo Surftest SJ-301 - Japão), a dureza superficial foi analisada em durômetro Sussen Wolpert, tipo Testor HT1 com método de Dureza Rockwell. A compatibilidade da resina com elastômeros de moldagem foi analisada com os criterios aderência do material de modelagem no molde e alteração na coloração do modelo obtido. O ensaio de resistência a compressão e tração por compressão diametral foram realizados na Máquina Universal de Ensaios DL2000 EMIC, com célula de carga de 2000 Kgf e velocidade de 1,3 mm/min. O ensaio de flexão foi realizado no mesmo equipamento com distância entre os apoios de 52 mm, célula de carga de 2000 Kgf e velocidade de 5 mm/min. O ensaio de resistência a fratura por impacto foi realizado na Máquina de Impacto CEAST modelo Resil 25 utilizando ensaio tipo Charpy. O ensaio de resistência ao desgaste por abrasão foi realizado em abrasímetro TABER, que determina a perda de massa por 1000 ciclos, utilizando o rebolo padrão CS-17 com 1000g de carga, ASTM D 4060. Os dados obtidos foram analisados estatisticamente variância e tukey com significância de 95%, e verificou-se que: A resina de poliuretano pura ou modificada com diatomita sobre os dois critérios adotados é compatível com silicone de condensação e adição; a capacidade de cópia da resina foi reduzida com a adição de diatomita mas permaneceu superior ao gesso tipo IV; a diatomita interferiu na rugosidade superficial da resina de poliuretano mas os valores foram menores que os apresentados pelo gesso tipo IV; a diatomita adicionada na resina de poliuretano aumentou a dureza superficial, a resistência a compressão, a tração por compressão diametral, a resistência ao desgaste por abrasão, ao impacto, e a flexão três pontos. A resina pura e a modificada com diatomita foram superiores ao gesso tipo IV para resiste resistência a compressão, a tração por compressão diametral, a resistência ao desgaste por abrasão, ao impacto e a flexão três pontos. Verificou-se comportamento dimensional semelhante para o gesso tipo IV e a resina de poliuretano modificada com diatomita, a resina pura contraiu, a diatomita reduziu a contração da resina de poliuretano. Com a realização desse estudo concluiu-se que: A resina de poliuretano pura ou modificada com diatomita é compatível com os elastômeros silicone de condensação e adição; a carga diatomita no percentual de 30% aumenta a dureza superficial, a resistência a compressão, a resistência a tração por compressão diametral, a resistência a fratura por impacto, a resistência a flexão três pontos, e a resistência ao desgaste por abrasão da resina de poliuretano; a resina de poliuretano quando modificada com 30% de diatomita apresenta comportamento dimensional semelhante ao gesso tipo IV; a diatomita reduziu a capacidade de copia da resina de poliuretano e aumentou sua rugosidade superficial, mas a resina carregada apresentou menor rugosidade superficial e maior capacidade de cópia que o gesso tipo IV; diante dos resultados encontrados com a modificação da resina de poliuretano com 30% de diatomita existe a viabilidade do uso desse material na modelagem odontológica<br>This study evaluated the high performance polyurethane resin 6470 and hardener Dt 082 (Huntsman Advanced Materials Química Brasil Ltda., supplied by Maxepoxi, Santo Amaro, São Paulo, Brazil) loaded with 30 % diatomite, for use in dental modeling. The material was manipulated in the ratio of 1:8 between resin and hardener, with the addition of the polyurethane accelerator in the proportion of one drop for each 200 grams of resin. Samples of pure resin, modified with diatomite type IV plaster (Fuji Rock EP), GC America Inc-USA, were obtained for the following tests: resistance to compression; diametral compression test ASTM D 695 2(a) to obtain tensile strength, and resistance to fracture by impact ISO 179-1: 2000., three point bending flexural test (ISO 1567:1999); resistance to wear by abrasion, Standard ASTM D 4060. Samples were analyzed with regard to dimensional behavior in a profile projector (Mitutoyo PJ-A3000 Japan); surface roughness Ra, and capacity to copy details were analyzed in a Roughness meter (Mitutoyo Surftest SJ-301 - Japan), surface hardness was analyzed in a Sussen Wolpert durometer Type Tester HT1, with the Rockwell Hardness method. The compatibility of the resin with molding elastomers was analyzed by the criteria of modeling material adherence to the mold and color alteration of the model obtained. The resistance to compression test and diametral compression test for tensile strength were performed in a Universal Test Machine EMIC DL2000, with a 2000 Kgf load cell and speed of 1.3 mm/min. The bending flexural test was performed in the same equipment with a distance of 52 mm between the supports, 2000 Kgf load cell and speed of 5 mm/min. The resistance to fracture by impact was tested in a CEAST Impact Machine model Resil 25 using the Charpy type test. The test for resistance to wear by abrasion was performed in a TABER abrasimeter, which determines the loss of mass per 1000 cycles, using the standard CS-17 abrasive wheel (grindstone) with a 1000g load, ASTM D 4060. The data obtained were statistically analyzed by the analysis of variance and Tukey tests at the level of significance of 95%, and it was verified that: The pure or diatomite-modified polyurethane resin, considering the two criteria adopted, is compatible with condensation and addition silicone; the copying capacity of the resin was reduced with the addition of diatomite, but remained superior to that of type IV plaster; the diatomite interfered in the surface roughness of the polyurethane resin, but the values were lower than those presented by the type IV plaster; diatomite added to the polyurethane resin increased the surface hardness, resistance to compression, traction resistance to diametral compression, resistance to wear by abrasion, impact, and to three point bending flexure. The pure and diatomite-modified polyurethane resin were superior to type IV plaster for resistance to compression, traction resistance to diametral compression, resistance to wear by abrasion, impact and three point bending flexure. Similar dimensional behavior was verified for type IV plaster and diatomite-modified polyurethane resin; the pure resin contracted, and the diatomite reduced polyurethane resin contraction. Conducting this study enabled the following conclusions to be drawn: The pure or diatomite-modified polyurethane resin is compatible with the condensation and addition silicone elastomers; the diatomite load of silicone percent increases the surface hardness, resistance to compression, traction resistance to diametral compression, resistance to fracture by impact, resistance to three point bending flexure, and resistance to wear by abrasion of polyurethane resin; when polyurethane resin is modified with 30% diatomite it has a dimensional behavior similar to that of type IV plaster; the diatomite reduced the polyurethane resin capacity to copy and increased its surface roughness, but the loaded resin presented less surface roughness and greater capacity to copy than the type IV plaster; in view of the results found by modifying the polyurethane resin with 30% diatomite, it is feasible to use this material in dental modeling.
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Molleri, Roberto Rogerio. "Avaliação in vitro da liberação de fluoretos de duas resinas compostas modificadas por poliacidos e um ionomerico modificado por resina." [s.n.], 2000. http://repositorio.unicamp.br/jspui/handle/REPOSIP/289718.
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Orientador: Luis Roberto Marcondes Martins<br>Dissertaçâo (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba<br>Made available in DSpace on 2018-07-27T13:31:40Z (GMT). No. of bitstreams: 1
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Previous issue date: 2000<br>Resumo: Muitos estudos demonstram a liberação de fluoretos dos cimentos de ionômero de vidro modificados por resina e de resinas compostas modificadas por poliácidos. Os efeitos anticariogênicos dos fluoretos têm levado a sua incorporação em um grande número de materiais dentários. O objetivo deste estudo foi quantificar e comparar in vitro a liberação de fluoretos de três materiais restauradores, duas resinas compostas modificadas por poliácidos, e um cimento de ionômero de vidro modificado por resina, nos períodos de 1,4,7,10,15 e 21 dias. Foram confeccionados cinco corpos-de-prova cilíndricos, com medidas de 3 mm de altura por 6 mm de diâmetro utilizando uma matriz metálica pré-fabricada. Os corpos de prova foram mantidos em recipientes com 20 mL de água destilada e deionizada, na temperatura de 37 graus centígrados. A água foi trocada após cada medição. A análise da água foi realizada por um potenciômetro modelo 720 A, marca Orion (Cambridge, MA, USA), acoplado a um eletrodo seletivo para fluoretos, modelo 9609, marca Orion (Cambridge, MA, USA), que determinou a quantidade de fluoretos em partes por milhão. Os dados foram submetidos à análise de variância e teste de Tukey. O estudo demonstrou o mesmo padrão de liberação de fluoretos para os três materiais, pois todos apresentaram maior liberação nas primeiras 24 horas. Após o décimo dia houve estabilização na liberação para todos os materiais. A liberação de fluoretos nas resinas compostas modificadas por poliácidos se manteve menor e constante, se comparada ao cimento de ionômero de vidro modificado por resina, que apresentou valores médios maiores<br>Abstract: Many studies have shown the release of fluorides frem resin-modified glass ionomer and polyacid-modified composite resin. The anticariogenic effects ofthe fluoride ions have called for their use in a great number of dental materiais. The aim of this study was to evaluate and compare, in vitro, the fluoride release of three restorative materiais, the polyacid-modified composite resin and a resin-modified glass ionomer, in 1,4, 7, 10, 15, and 21 days. Five cylindrical samples were made, 3 mm high by 6 mm in diameter by using a pre-built metallic matrix. The samples were stored in 20 mL containers in deionized, distilled water, at 37°C. The water was replaced after each measurement. The water analysis was done by an Orion 720 A model potentiometer (Cambridge, MA, USA), attached to an Orion 9609 model selective electrode for fluorides (Cambridge, MA, USA), which determined the amount of fluorides in parts per milion. The study showed the same fluoride release pattern forthe three materiais, as ali ofthem presented a high release in thefirst24 hours. Afterthetenth day, there was a stabilization in the release for ali materials. The fluorides release in the 'polyacid-modified composite resin remained lower and constant, comparing to the resin-modified ionomer glass cement, which showed higher mean values<br>Mestrado<br>Mestre em Materiais Dentários
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Mezzenga, Raffaele. "Hyperbranched polymers as modifiers for thermoset resins /." [S.l.] : [s.n.], 2001. http://library.epfl.ch/theses/?nr=2428.
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Almahdy, Ahmed. "In-vitro assessment of modified resin adhesive-tooth interfaces." Thesis, King's College London (University of London), 2013. https://kclpure.kcl.ac.uk/portal/en/theses/invitro-assessment-of-modified-resin-adhesivetooth-interfaces(c820f600-610a-49cc-be4e-efce959120b4).html.
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Objectives: This research aimed to characterize the interfacial characteristics of modified dental resin-based adhesive systems bonded to sound and carious dental tissue. The modification included the incorporation of matrix metalloproteinase (MMP) inhibitors within the primers of these adhesives. Materials and methods: Two MMP inhibitors (BB94 and GM6001) were added to three adhesive primers, Optibond FL “OB” (Kerr, USA), Prime&Bond NT “PB” (Dentsply, USA) and G-Bond “GB” (GC, UK) and bonded to sound dentine. The inhibitory effect of the modified adhesive on recombinant MMPs and on sound dentine MMPs was assessed using FRET-based measurement of MMP activity and substrate zymography, respectively. Micro-tensile bond strength and micro-permeability were used to evaluate the modified adhesives’ physical properties. Micro-Raman spectroscopy analysis was validated on carious dentine and it was used to evaluate the interface between the modified OB primer and caries-affected dentine. The inhibitory effect of the modified adhesive on caries-affected dentine was studied using in-situ zymography. Results: The fluorometric assay and zymography showed that modified adhesives had high affinity toward both synthetic FRET-peptides and dentine powder substrates, respectively. The immediate micro-tensile bond strength was enhanced for OB (48.0 MPa ± 20.3 SD for BB94 and 42.0 MPa ± 18.7 SD for GM6001) and GB (34.8 MPa ± 19.2 SD for BB94 and 41.7 MPa ± 17.6 SD for GM6001). However, no changes were detected between the control and the inhibitor groups following 3-month storage. Additionally, the micro-permeability of PB and GB showed less dye seepage, to the “hybrid layer” and to the “adhesive”, respectively. The caries-infected dentine was defined significantly by the KHN (< 20.6), AF (> 14.4 A.U.) and by the relative contribution of the mineral (< 36.4%), Porphyrin fluorescence (> 25.3%) and Infected dentine signal (> 0.3%) Raman clusters. The caries-affected dentine-adhesive interface exhibited more hydrophobic resin (32.8% ± 3.9 SD) that maintained over four-week aging. Conclusions: The addition of MMP inhibitors to contemporary dental adhesive systems resulted in modified adhesives that had an enhanced dentine-adhesive interface with inhibited MMP activity. Such properties enhance the clinical performance of adhesive systems.
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Sidhu, Sharanbir Kaur. "Resin-modified glass ionomer restorative materials : an evaluation involving microscopy." Thesis, King's College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362847.
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Gonçalves, Priscilla Santana Pinto. "Selamento de fossas e fissuras após 6 meses com diferentes materiais: Resinoso X Ionómerico." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/25/25145/tde-03092013-154047/.
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Este estudo avaliou e comparou, após 6 meses, dois materiais usados como selantes de fossas e fissuras, FluroShield® (Dentsply, Germany) e Clinpro™ XT Varnish (3M ESPE, Dental Products, St. Paul, MN, U.S.A.) quanto à retenção e características superficiais. Além disso, comparou-os, com um grupo controle não selado, com relação à incidência de cárie no período. Participaram deste trabalho, 31 crianças de 6 a 8 anos de idade, com no mínimo dois primeiros molares permanentes hígidos e história de cárie, num total de 114 dentes divididos aleatoriamente em três grupos: CLP (Clinpro™ XT Varnish), FS (FluroShield®) e ctr (Controle). O selamento foi realizado sob isolamento relativo para ambos os materiais testados, após profilaxia prévia com jato de bicarbonato de sódio e água e, condicionamento com gel de ácido fosfórico a 35% por 15 segundos. A avaliação clínica foi realizada por dois examinadores calibrados após 6 meses. Avaliou-se a retenção e a incidência de cárie nas cinco áreas oclusais: OM, OC, OD, OV e OL; e as características superficiais e a retenção considerando a superfície oclusal como um todo. Houve diferença estatisticamente significante para a prevalência de cárie (teste de Kruskal Wallis, p=0,000 a 0,007), para todas as áreas, entre os grupos selados (CLP e FS) e o controle. Sendo que quanto à incidência, só foi verificada diferença significante para a área OL (p=0,014). O teste do Qui-quadrado identificou que não houve diferença estatisticamente significante entre os materiais, com relação à taxa de sucesso de retenção da superfície oclusal como um todo, quando se considerou o somatório das cinco áreas (p=0,079) ou quando se verificou a retenção por superfície (p=0,141). No entanto, a análise do conjunto de critérios de retenção na superfície oclusal toda, mostrou uma diferença estatisticamente significante para o FS (teste de Mann-Whitney, p=0,002). Em relação às características superficiais, o FS apresentou superioridade durante o período estudado de forma significativa, indicada pelo teste de Mann-Whitney, para a deterioração marginal (p=0,000), descoloração marginal (p=0,008), e descoloração superficial (p=0,001). Ele também foi superior, mas não significante, quanto à textura superficial. A frequência de bolhas nas superfícies seladas não mostrou diferença significativa (teste do Qui-quadrado, p=0,758) entre os materiais. Desta forma, pode-se concluir que ambos os materiais foram efetivos nos primeiros 6 meses de avaliação, embora, tenha havido melhor desempenho clínico do selante FluroShield®.<br>This study evaluated and compared two dental sealants, for 6 months. The materials, Fluroshield® (Dentsply, Germany) and Clinpro™ XT Varnish (3M ESPE Dental Products, St. Paul, MN, USA) were analyzed with regard their retention and superficial characteristics. They also were compared with a control group, without sealant, regarding the dental caries incidence. The sample was composed by 31 children from 6 to 8 years of age, with at least two sound first permanent molars, but with a dental caries history. A total of 114 teeth were randomly alocated in three groups: CLP (Clinpro™ XT Varnish), FS (Fluroshield®) and ctr (Control). The sealings were applyed under relative isolation after a previous prophylaxis with a water-air-polishing jet, and an enamel etching with a 35% phosphoric acid gel for 15 seconds. Clinical evaluation was performed by two calibrated examiners after 6 months considering: the sealant retention and the incidence of occlusal caries in five areas: OM, OC, OD, OV and OL and finally, the surface characteristics and retention considering the occlusal surface as only one area. It was shown a significant difference (Kruskal-Wallis test, p=0.000 to 0.007) for the caries prevalence in all areas comparing the sealed group (CLP and FS) versus control. Whereas the incidence, it was only verified a significant diference for the OL area (p=0.014). There was no significant difference (Chi-square test, p=0.079) between the materials regarding the success rate of retention for the occlusal surface when it was considered the sum of the five areas, or for the occlusal surface without divisions (p=0.141). Nevertheless there was a significant difference between the sealants (Mann-Whitney test, p=0.002), with better results for the FS group, when it was analysed the influence of all the retention criteria. Regarding the surface characteristics, the FS group showed a significant superiority (Mann-Whitney test) during the period of the study for the impairment marginal (p=0.000), marginal discoloration (p=0.008), and surface discoloration (p=0.001). Although FS had also been superior for the surface texture, this result was not significant. The frequency of bubbles in the sealed surfaces was not significant (Qui-square test, p=0.758) between the materials. Thus, it can be concluded that both materials were effective during this first 6 months of evaluation, although it is evident that the Fluroshield® sealant had shown a better clinical performance.
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Ashaduzzaman, Md. "Physico-mechanical and decay resistance properties of bio-resin modified wood." Thesis, Bangor University, 2014. https://research.bangor.ac.uk/portal/en/theses/physicomechanical-and-decay-resistance-properties-of-bioresin-modified-wood(f4588ffc-250d-4f89-95f5-8f9ea381dba7).html.
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Rix, Douglas. "Bond strengths and fluoride release of modified glass ionomer and resin adhesives." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ39873.pdf.
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Ro, Emily Y. "Evaluation of Shear Bond Strength of Two Resin-Modified Glass-Ionomer Cements." VCU Scholars Compass, 2003. http://hdl.handle.net/10156/1759.
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Torabzadeh, Hassan. "Laboratory and clinical investigations into resin-modified glass-ionomer cements and related materials." Thesis, University of Bristol, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337636.
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Wong, Dai-cheung Jonathan, and 黃大彰. "Effects of zirconate coupling agents on resin modified composites bonding to zirconia surfaces." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B4833473X.
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Bacchi, Ataís 1986. "Resin cements modified with thiourethane polymer additives = cement layer and bonding interface properties." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288589.
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Orientador: Rafael Leonardo Xediek Consani<br>Texto em português e inglês<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba<br>Made available in DSpace on 2018-08-25T06:50:42Z (GMT). No. of bitstreams: 1
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Previous issue date: 2014<br>Resumo: O objetivo neste estudo foi formular cimentos resinosos a partir de oligômeros tiouretanos, com o propósito de melhorar as propriedades mecânicas do material e minimizar a contração e a tensão de polimerização. Materiais fotopolimerizados e de ativação dupla foram avaliados. Dois oligômeros foram sintetizados ao combinar 1,6-hexanodiol-diisocianato (HDDI) (alifático) com pentaeritritol tetra-3-mercaptopropionato (PETMP) ou 1,3-bis(isocianato-1-metiletil) benzeno (BDI) (aromático) com trimetilol-tris-3-mercaptoproprianato (TMP), na proporção de 1:2 de isocianato e tiol, mantendo grupos tiol pendentes. Inicialmente, 10-30% em peso de ambos os tiouretanos foram adicionados à matriz orgânica formada por BisGMA-UDMA-TEGDMA (nas proporções 50-30-20%, em peso) para o cimento experimental fotopolimerizado. A este, 25% em peso de partículas inorgânicas foram adicionadas. Para o cimento de cura dual, composto pela mesma matriz orgânica e partículas de carga, e para dois materiais comerciais ¿ RelyX Veneer e RelyX Ultimate (3M Espe) - apenas a versão aromática em 10 e 20% em peso foi avaliada. Para todos os materiais, as propriedades mecânicas foram avaliadas através do teste de flexão por três pontos (ISO 4049) para a resistência à flexão (RF), módulo de elasticidade (E) e tenacidade (T). A tenacidade à fratura (KIc) foi avaliada em amostras entalhadas (ASTM Standard E399-90). A tensão de polimerização (TP) foi avaliada usando o aparelho Bioman. Os materiais fotopolimerizados foram avaliados quanto à contração de polimerização (CP) pelo método do disco aderido e a cinética de polimerização (grau de conversão (GC), taxa máxima de polimerização (Rpmax) e vitrificação) avaliadas por infravermelho. A união de uma cerâmica vítrea e um compósito restaurador indireto à dentina foi avaliada com o cimento comercial dual com 0, 10 e 20 % de tiouretano. Os resultados foram submetidos à Análise de Variância e teste de Tukey (?=5%). Quanto ao GC, ocorreu aumento pela utilização da versão alifática nos cimentos experimentais fotoativados; entretanto, a versão aromática não promoveu alteração relevante no GC final dos materiais. Rpmax foi menor nos grupos tiouretanos sendo também significantemente menor para os alifáticos quando comparados aos aromáticos. Apesar de os tiouretanos influenciarem a vitrificação (p=0,035) no cimento experimental, os resultados não foram conclusivos pela análise de Tukey. No cimento comercial foi observado aumento da vitrificação pelo uso do oligômero. Nos cimentos experimentais, RF aumentou com o oligômero aromático e 20% em peso do alifático nos cimentos fotopolimerizados; para E, a versão aromática no cimento com ativação dupla e 10% em peso no material fotopolimerizado causou aumento nos valores. Os materiais comerciais tiveram redução de E com 20% em peso de oligômero, decorrente da redução da proporção de carga inorgânica da matriz. Aumento significante em tenacidade ocorreu nos grupos alifáticos no material fotopolimerizado e para 20% em peso de aromático no cimento dual. K1c aumentou significativamente em ambos os materiais experimentais contendo tiouretano em ambas as concentrações, sendo mais pronunciada em alifáticos na versão fotopolimerizada. Ainda, KIc aumentou com 20% em peso do oligômero em materiais comerciais. A CP reduziu significantemente nos grupos tiouretanos, especialmente para o oligômero alifático no cimento experimental fotopolimerizado. A TP reduziu com os oligômeros de maneira mais acentuada para alifáticos no cimento experimental fotopolimerizado. O uso dos aromáticos em cimentos de ativação dupla também causou redução na TP, e quando com 20% em peso nos materiais comerciais. A modificação do cimento comercial de ativação dupla com 20% em peso do oligômero aromático aumentou a adesão do compósito indireto e da cerâmica vítrea à dentina coronária. Em geral, oligômeros tiouretanos melhoraram as propriedades dos cimentos resinosos avaliados<br>Abstract: The aim of this study was to formulate resin cements with thio-urethane oligomers to improve mechanical properties and minimize shortcomings related to the volumetric shrinkage and polymerization stress. Light- and dual-cured materials were evaluated. Oligomers were synthesized by combining 1,6-Hexanediol-diissocyante (aliphatic) with pentaerythritol tetra-3-mercaptopropionate (PETMP) or 1,3-bis(1-isocyanato-1-methylethyl)benzene (aromatic) with trimethylol-tris-3-mercaptopropionate (TMP), at 1:2 isocyanate:thiol, leaving pendant thiols. Oligomers were added at 10-30wt% to BisGMA-UDMA-TEGDMA (5:3:2). 25wt% silanated inorganic fillers were added. The dual-cured cement, composed by the same organic matrix and filler particles, and for two commercial cements (RelyX Veneer e RelyX Ultimate; 3M Espe) were only evaluated with the addition of the aromatic version in 10 and 20 wt%. For all materials, the mechanical properties were evaluated by the three-point bending test (ISO 4049) for the flexural strength (FS) elastic modulus (E) and toughness (T). The fracture toughness was evaluated with notched specimens (ASTM Standard E399-90). The polymerization stress (PS) was evaluated in the Bioman. For the light-cured materials, the volumetric shrinkage (VS) was evaluated by the bonded-disc method and the polymerization kinetics ¿ degree of conversion (DC), maximum rate of polymerization (Rpmax) and vitrification ¿ evaluated by near-infrared (NIR). The bonding of a glass ceramic and an indirect composite to dentin were evaluated with the dual-cured commercial cement with 0, 10 and 20 wt% of thio-urethane. Data were analyzed with ANOVA and Tukey¿s test (?=5%). Regarding the DC, an increase was observed in the light-cured materials containing the aliphatic version. The aromatic oligomer did not promote relevant influence the materials. Rpmax was lower for thio-urethane groups being also significantly lower for the aliphatic group when compared to the aromatic. ANOVA has shown the thio-urethane influencing the vitrification (p=0.035) in the experimental cement, but the results were not conclusive by the Tukey¿s test. For the commercial cement, an increase in the vitrification was observed in the thio-urethane-modified group. For experimental cements, FS increased with the use of 10-30 wt% aromatic oligomer and with 20 wt% of aliphatic for light-cured cements. E was only higher for the aromatic version at 10 wt%. The commercial cements presented a reduction in E with 20 wt% of oligomer caused by the reduction in the filler proportion. A significant increase in T occurred in the aliphatic groups for the light-cured group and for 20 wt% of aromatic in the dual-cured cement. KIc significantly increased in both experimental materials formulated with thio-urethane for both concentrations, being more evident for the aliphatic group in the light-cured version. KIc also increased with the aromatic oligomer in commercial materials. The VS was significantly reduced in the thio-urethane groups, mainly for the aliphatic version in the light-cured cement. The PS decreased in the groups formulated with oligomers in the light-cured experimental materials, being also significant for aliphatics. The use of aromatic oligomer also reduced the PS when added to a 20 wt% proportion of organic matrix. The modification of a dual-cured commercial cement with 20wt% of aromatic oligomer led to an increase in the bond strength of an indirect composite and a glass ceramic to the coronal dentin. Thus, it can be concluded that thio-urethane oligomers improved the properties of resin cements<br>Doutorado<br>Protese Dental<br>Doutor em Clínica Odontológica
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Xie, Shaoxiong. "COMPARATIVE STUDY ON TIP/TIA/ZRP/TEOS MODIFIED EPOXIDES RESIN: ANTI-CORROSION PERFORMANCE." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1534159109126582.
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Afonso, Rebeca Lima [UNESP]. "Estudo da adesão dentinária em restaurações realizadas com ionômero modificado por resina: influência de técnicas restauradoras e do preparo cavitário." Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/95482.
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afonso_rl_me_araca.pdf: 1791982 bytes, checksum: 34a9a88d60d85fbbe1aed0817c8d636e (MD5)<br>O objetivo deste trabalho foi avaliar a interação ocorrida entre um material ionomérico e o tecido dentinário, quando realizadas duas técnicas de preparo cavitário e diferentes tratamentos superficiais. Para tanto, foram utilizados 40 dentes decíduos cariados (n=10). Os preparos cavitários foram realizados pela técnica convencional, com instrumentos cortantes rotatórios ou pela técnica empregada no Tratamento Restaurador Atraumático (ART), com uso de instrumentos cortantes manuais. Para o condicionamento da superfície dentinária foram utilizados o ácido fosfórico a 37% e o poliacrílico a 12,5%. A restauração dos espécimes foi realizada com o cimento de ionômero de vidro modificado por resina Fuji II LC. O tratamento realizado em cada grupo foi: (1) curetas dentinárias + ácido fosfórico + Fuji II LC; (2) brocas + ácido fosfórico + Fuji II LC; (3) curetas dentinárias + ácido poliacrílico + Fuji II LC; (4) brocas + ácido poliacrílico + Fuji II LC. Após a descalcificação e inclusão em parafina, os espécimes foram seccionados, montados seqüencialmente em lâminas de vidro, corados pelo método de Brown & Brenn e analisados em microscópio óptico com ação de luz polarizada AXIOPHOT (ZEISS) a 400X de aumento. Os resultados foram analisados de forma quantitativa e qualitativa. Os testes estatísticos, Análise de variância a um critério e teste de Tukey ao nível de 5%, mostraram que em relação à área de interação dente-material restaurador, os espécimes do grupo IV não apresentaram formação de tags em tecido dentinário, enquanto que as demais combinações de agentes condicionadores e técnicas possibilitaram a formação de tags com comprimentos semelhantes. A análise qualitativa mostrou que ambos os grupos tratados pela técnica do ART, apresentaram uma superfície cavitária irregular, além de inúmeras colônias bacterianas ao longo de...<br>The objective of the present study was to analyze the interaction between a ionomeric material and dentinal tissue using two cavity preparation techniques and different surface treatments. For this purpose, 40 deciduous teeth (n = 10). Cavity preparation was performed with rotary cutting instruments by the standard technique or by the technique employed in atraumatic restorative treatment (ART) using manual cutting instruments. For conditioning of the dentinal surface 37% phosphoric acid and 12.5% polyacrylic acid were used. Restoration of the specimens was performed with Fuji II LC resin-modified glass ionomer cement, and the groups were submitted to the following treatments: (1) dentinal curettes + phosphoric acid + Fuji II LC; (2) burs + phosphoric acid + Fuji II LC; (3) dentinal curettes + polyacrylic acid + Fuji II LC; (4) burs + polyacrylic acid + Fuji II LC. After decalcification and paraffin embedding, the specimens were sectioned, mounted sequentially on glass slides, stained by the method of Brown and Brenn, and analyzed under an Axiophot (Zeiss) polarized light microscope. The results were analyzed quantitatively and qualitatively by analysis of variance and by the Tukey test. With respect to the interaction area between the tooth and restorative material, specimens of group 4 showed no formation of tags in dentinal tissue, whereas the other combinations of conditioning agents and techniques led to the formation of tags of similar lengths. Qualitative analysis showed an irregular cavity surface in the two groups treated by the ART technique, in addition to numerous bacterial colonies throughout the extension of the cavities. Formation of an interaction area between dentinal tissue and ionomeric material was observed in all groups, with this interaction being more regular and showing less variation in thickness in group 2.
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林建揚. "= Polysiloxane modified epoxy resins." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/65112981154745581805.
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YU, CHENG-HSIEN, and 游承憲. "Study on Epoxy Resins Modified Polycarbonate." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5hk766.
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LIN, CHIH-CHIEN, and 林志謙. "Study of nanosilica modified epoxy resins." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/56074630138484336559.
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碩士<br>東海大學<br>化學工程與材料工程學系<br>105<br>In this study, epoxy resin composites containing curing agent, accelerator, and nanosilica (nano-SiO2) are prepared at different ratios, and then cured by heating. The peak temperature and reaction heat (ΔH) are evaluated via differential scanning calorimeter (DSC). The storage modulus, loss modulus, and glass transition temperature are evaluated via dynamic mechanical analysis (DMA). The thermal expansion coefficient (α) and glass transition temperature (Tg) are evaluated via thermal mechanical analysis (TMA). The initial degradation temperature and temperature of maximum rate of degradation are evaluated via thermal gravimetric analyzer (TGA).
The DSC results show that the peak temperatures of the epoxy resins decrease with the increasing accelerator percentages. The reaction heats of the epoxy resins increase with the increasing accelerator percentages. MI results in better properties than those of BDMA and MON accelerators at same doping amounts. The peak temperatures and reaction heats are not affected with doping amounts of nanosilica.
The DMA results show that epoxy resins NPEL-128 result in higher glass transition temperatures than those of Epikote-828 at the same doping amount of accelerator. 1.0-MI-2.5-Si results in the highest glass transition temperature of 173 ℃ for epoxy resin NPEL-128 doped nanosilica of 2.5 phr.
The TMA results show that 1.0-MI-5.0-Si results in the lowest thermal expansion coefficient of 52.4 μm/m℃ and the highest glass transition temperature of 153 ℃ for epoxy resin NPEL-128 doped nanosilica of 5.0 phr.
The TGA results show that 1.0-MI-5.0-Si results in the highest initial degradation temperature of 302 ℃ for epoxy resin NPEL-128 doped nanosilica of 5.0 phr. 1.0-MI-2.5-Si results in the highest maximum rate of degradation temperature of 413 ℃ for epoxy resin NPEL-128 doped nanosilica of 2.5 phr.
The optimum parameter of epoxy resin formulation is 1.0-MI-5.0-Si. The amounts of epoxy resin NPEL-128, curing agent DICY, accelerator MI, and nanosilica are 10 g, 7.5 phr, 1.0 phr, and 5.0 phr, respectively.
Keywords: epoxy, accelerator, nanosilica
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蕭涵HSIAO, HAN, and 蕭涵. "Study of carbon nanotube modified epoxy resins." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/nsm2j2.
Full textAbstract:
碩士<br>東海大學<br>化學工程與材料工程學系<br>105<br>Abstract
In this study, the property variations of epoxy resins modified by carbon nanotube are investigated. Epoxy resins are cured by heating to initiate free radical polymerization. The thermal properties of epoxy resins are analyzed by various equipments. Two epoxy resins NPEL-128 and Epikote-828, curing agent DICY (Dicyandiamide), and three accelerator MI (2-Methylimidazole), Monuron (3-(4-chlorophenyl)-1, 1-dimethylurea) and BDMA (N, N-dimethylbenzylamine) are used. Five different amounts of multi-walled carbon nanotube are doped. After samples were cured, the peak temperature and reaction heat (ΔH) are evaluated via differential scanning calorimeter (DSC). The viscoelastic and glass transition temperature (Tg) are evaluated via dynamic mechanical analysis (DMA). The thermal expansion coefficient (α) and Tg are evaluated via thermal mechanical analysis (TMA). The initial cracking temperature, temperature of maximum rate of cracking, and remaining amounts are evaluated via thermal gravimetric analyzer (TGA). The optimal formula is found, and the influence of carbon nanotube doping amounts on material properties is investigated.
The DSC results show that peak temperatures of all formulas increase with increasing doping amounts of carbon nanotube, but ΔH of all formulas decrease. At same doping amounts of carbon nanotube, formulas with accelerator BDMA have lower peak temperatures, but formulas with accelerator MI have higher ΔH.
The DMA results show that storage modulus E’ of glassy state, storage modulus E’ of rubber state, and tanδ Tg of all formulas increase with increasing doping amounts of carbon nanotube. At same doping amounts of carbon nanotube, formulas with accelerator MI have higher E’, and accelerator Monuron have higher tanδ Tg.
The TMA results show that α of all formulas decrease with increasing doping amounts of carbon nanotube, but Tg of all formulas increase. At same doping amounts of carbon nanotube, formulas with accelerator MI have lower α, but formulas with accelerator Monuron have higher Tg.
The TGA results show that initial cracking temperatures and remaining amounts of all formulas increase with increasing doping amounts of carbon nanotube, but the maximum cracking temperatures of all formulas decrease slightly. At same doping amounts of carbon nanotube, formulas with accelerator MI have higher initial cracking temperatures and remaining amounts.
Comparing all properties analyzed by DSC, DMA, TMA and TGA, sample formula 828-MI-2.0 with Epikote-828 epoxy resin of 10 g, curing agent DICY of 7.5 phr, accelerator MI of 1.0 phr, and carbon nanotube of 2.0 phr is the optimal formula in this study.
Keywords: epoxy resins, curing agent, accelerator, carbon nanotube
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吳欣有. "Polysiloxand Modified Epoxy Resins: Joint Interpenetrating Polymer Networks." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/58121778934278410186.
Full textAbstract:
碩士<br>輔仁大學<br>化學學系<br>85<br>The flexibility of liquid rubber and well dispersion of rubbery phase can toughen epoxy resin by promoting process zone mechanisms. Polydimethylsiloxane, owing to its superior flexibility and thermal sta- bility, always regarded as one of the best candidates to modify the me- chanical properties of the epoxy resins. However, polydimethylsiloxane is completely immiscible with epoxy resin restricted its application.
In this study, two types of polydimethylsiloxane-α, ω-diol were used to improve the two compatibility between siloxane and epoxy res- ins. In order to control the phase separation, two different approaches were used: (1) alternating molecular weight of the modifier. (2) changing the curing rate of the epoxy resin.
The results of this study illustrate that this modifier is fully compatible with the epoxy resins, no phase separation (nibber domain) occurred in the final cured samples. The tree leaf type crystals, due to the strain-induced crystallization, were observed in both tensile as well as fracture samples. Although there is no appropriate rubber domain, the experimental results indicate that strain-induced crystallization and larger plastic zone size of PDMS modified epoxy resins could improve the fracture energy significantly. All of the results could be explained successfully by the contribution of the plastic zone size.
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HOU, JUN-HUI, and 侯俊輝. "Syntheses and applications of modified cationic epoxy resins." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/98762675496598932208.
Full textAbstract:
碩士<br>大同工學院<br>化學工程研究所<br>78<br>(A) 本篇合成一系水溶性陽離子樹脂，由二乙基胺與環氧樹脂反應生成三級胺末端之
樹脂後，側鏈接上交鏈基2-乙基乙醇杜塞 TDI／二乙基胺乙醇杜塞 TDI而成。這些樹
脂其側鏈中醇基與半杜塞-TDI之莫耳比為1：1，改變及側鏈中三級胺之相對量，探討
其樹脂性質與電著性質，由實驗結果發現，側鏈交鏈基所含之三級胺基之比率改變時
，對樹脂電著液之諸多性質影響頗大。三級胺基比值提高時，其乳化液之PH亦愈高，
且皮膜之交鏈性在低溫時亦愈高。樹脂乳化液之導電性，電著滲透力會隨三級胺基量
之增加而增加，但電著速率和電著量則隨三級胺基量之增加而減少，當樹脂之側鏈三
級胺占總側鏈之20∼60% 時，該樹脂電著膜之物理化學性質適合實用規格。
(B) 本篇合成之自我交鏈型環氧樹脂是由苯甲胺與環氧樹脂反應成苯甲胺改質環氧樹
脂，再以二級胺開環得到環氧樹脂—加成體，然後與2-EH-TDI之 TDI半保護交鏈體反
應而得。其特點是由苯甲胺衍生之三級胺會增加樹脂中三級胺之含量，因此陽離子之
量會增加，進而提高其導電度與滲透力。由實驗結果顯示，由此種樹脂所配成之電著
液欲其乳化之PH值適當範圍約在5.3∼4.6，而助溶劑 BCS之添加量約在 4∼8%。另外
，PH值之提高會使電著量與破壞電壓也跟著增加，但導電度與電著滲透力會降低。又
BCS 量之增加會降低其電著量與破壞電壓，至於樹脂濃度之增加會提高其導電度，電
著滲透力與電著量。且由此種樹脂配成之電著液進行電著熱硬化後之電著膜其附著度
，耐酸鹼性與硬度皆適合實用規格。
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Hsu, Shih-Hsuan, and 徐世炫. "The preparation method and properties of modified polyamideimide resins." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/gvhcwj.
Full textAbstract:
碩士<br>國立臺北科技大學<br>分子科學與工程系有機高分子博士班<br>103<br>This research is mainly to study the preparation method and properties of modified polyamideimide resins. In the lab we use different amounts of bismaleimide monomer, hoping to reduce the reaction temperature polyamideimide resin. While in the present study, using a differential scanning calorimetry to measure the glass transition temperature of the resin and the conversion rate.
The experimental results showed that the bismaleimide monomer modified polyamideimide resin, can indeed reduce the reaction temperature polyamideimide resin, this bismaleimide monomer modified polyamideimide resin when it impregnated or coated with quick response control curing reaction.
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Chen, Tsung-Yu, and 陳聰育. "Surface Characterizations of Siloxane-Modified Sulfone- Containing Epoxy Resins." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/76100527480899998575.
Full text
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CHEN, JIAN-HONG, and 陳建宏. "Fracture toughness of thermoplastics modified epoxy resins and composites." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/28956086716527735530.
Full text
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Daniel, Iris. "Biodegradation of Polyacid Modified Composite Resins by Human Salivary Esterases." Thesis, 2009. http://hdl.handle.net/1807/18268.
Full textAbstract:
Polyacid modified composite resins (PMCR) are designed to combine the aesthetics of composites-resins with the fluoride release of glass-ionomers. Objectives: to compare the relative biostability and fluoride release of PMCR (F2000 [3M]; Dyract eXtra [DENTSPLY]) and a composite-resin (Z250 [3M]). Standardized samples were incubated in either buffer or human saliva derived esterases (HSDE) for up to 14 days. High- performance-liquid-chromatography revealed higher amounts of degradation products for all HSDE incubated groups, as compared with the buffer. Z250 samples released higher amounts of bishydroxypropoxyphenylpropane (Bis-HPPP) and triethylene-glycol-dimethacrylate (TEGDMA) than both PMCR. Dyract eXtra and F2000 samples released unique degradation products, respectively di-ester of 2-hydroxyethyl di-methacrylate with butane tetracarboxylic acid (TCB) and glyceryl dimethacrylate (GDMA). F2000 samples released more fluoride for both incubation periods in the presence of HSDE as compared with Dyract eXtra samples. Scanning electron microscopy analysis confirmed the greater degradation of both PMCR, as compared with Z250.
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Lin, Shyue-Tzoo, and 林學佐. "Synthesis and Characterizations of Siloxane-Modified Epoxy Resins and Applications." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/24693883477191802210.
Full text
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Jan, Yih-Dean, and 詹益典. "Properties of dental methacrylate resins with different urethane-modified side chains." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/67211360209326920738.
Full textAbstract:
博士<br>國立臺灣大學<br>臨床牙醫學研究所<br>100<br>Composite resins are currently the most popular dental restorative materials worldwide. Composite resins provide certain advantages such as good esthetics, easy application, and lower costs. However, there remain some disadvantages to their use, such as polymerization shrinkage, low wear resistance, and marginal discoloration. Composite resins are composed of organic monomers and inorganic fillers. High molecular weight dimethacrylate monomers with low polymerization shrinkage and high strength, such as bisphenol A-glycidyl dimethacrylate (bis-GMA), are most commonly used. The high viscosity of bis-GMA reduces the loading of fillers and also the degree of conversion of the monomers in the absence of other low viscosity diluents. Low molecular weight diluent monomers, such as triethylene glycol dimethacrylate (TEGDMA), are often added to reduce viscosity and increase the reactivity and conversion rate. However, the diluent monomers also increase polymerization shrinkage, leading to polymerization stress, debonding at the restoration-tooth interface, secondary caries, postoperative sensitivity, pulpal irritation, and marginal discoloration. Polymerization shrinkage is the principal cause of failure of clinical dental composite resin fillings. Reducing this shrinkage, thus, represents one of the most important goals in the development of new matrices for composite resins.
Currently, there remains a lack of “non-shrinkage” composite resins worldwide. In this study, we aimed to develop low-shrinkage composite resins for dental application. As expected, the higher the molecular weight and volume the monomer, the less extensive the shrinkage when polymerized. Most commercial dental composite resins are composed of bis-GMA or its derivatives. We increased the molecular weight and volume of the dimethacrylate molecule by conjugating functional side chains to the dimethacrylate structure. Urethane, which is a compound of diisocyanate and 2-hydroxyethyl methacrylate (HEMA), is a material suitable for use as a dimethacrylate side chain. Polyurethane displays certain advantages, such as low shrinkage, high wear resistance, and good biocompatibility. We selected three diisocyanates with different chemical structures as side chain
materials: 1,6-Diisocyanatohezane (HDI),
4,4’-diisocyanatodicyclohexylmethane (H12MDI) and toluene 2,4-diisocyanate (TDI). HDI is a linear structure molecule. H12MDI contains two aliphatic rings (cyclohexane) linked by a methyl group, whereas TDI contains a toluene moiety.
When conjugated to dimethacrylate, these three chemical structures reduced polymerization shrinkage and increased the mechanical strength of the composites. Different structures and numbers of side chains on dimethacrylate provided different results. The molecular weight and viscosity of experimental resins were increased as functional side chain density was increased. The polymerization shrinkage and degree of conversion were decreased when functional side chain density was increased. Polymerization shrinkage in the DM-M-1.5c and DM-T-1.5c groups was significantly less extensive than in the other groups (p<0.05). Although the degree of conversions of these two groups were significantly lower than that of the control group, the surface hardness values were equal to or significantly higher than that of the control group because of increasing functionalities of the side chain-modified groups. There were non-significant differences between these two groups and the control group in cell vitality. The biocompatibility of dental resin is related to the stereo hindrance of resin matrix molecular structures. When the ratio of HDI, H12MDI or TDI functional side chain to dimethacrylate is increased, the stereo hindrance of resin structure is increased, more toxic resin monomers are trapped in the complicated resin structure, and thus the resin matrix reveals less cytotoxicity. The urethane modification of dimethacrylate, therefore, represents an effective means of reducing polymerization shrinkage and increasing surface hardness. The modified dimethacrylate with good biocompatibility might be suitable for dental use in the future.