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1

Macauley, Nicola Jayne. "Extrusion and thermoforming of polypropylenes." Thesis, Queen's University Belfast, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337017.

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2

Lam, Ying. "Quantification of dynamic mixing characteristics during polymer extrusion." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B36540869.

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3

Lam, Ying, and 林瀅. "Quantification of dynamic mixing characteristics during polymer extrusion." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B36540869.

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4

Zhao, Jianhong. "Solid state extrusion of polymers through convergent-divergent dies." Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/22079.

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Compared with metals, polymer materials have Iow strength and stiffness. However, molecular orientation can enhance many mechanical properties of polymer materials in the direction of orientation. Studies on solid state polymer extrusion (Le. extrusion carried out at temperatures below the melting point of the polymer) through convergent dies show that it is possible to produce extrudates exhibiting a high degree of monoaxial orientation in the extrusion direction. Although the strength of these extrudates has been greatly enhanced in the orientation direction, the strength decreases in the transverse direction to the axial orientation. Biaxially oriented polymer materials, on the other hand, show increased mechanical properties in more than one direction. But so far, extrusion processes that confer orientation in more than one direction have not received much attention. The present work is concerned with the development of biaxial orientation in thick thermoplastics extrudates by extrusion through dies exhibiting simultaneously converging and diverging walls perpendicular to each other and with a cross-section area at the die entry being the same as at the exit. Four die designs are examined, known respectively as the dual-taper die, the expansion fish-tail die, the constant fish-tail die and the cross die, using polytetrafluoroethylene and ultra-high molecular weight polyethylene. Measurements of birefringence and tensile strength on sections of the extrudates have shown that a preferential orientation along the transverse direction is normally achieved with the fish-tail dies and the dual-taper die, while the extrudates obtained with the cross die were found to exhibit a cross-ply orientation pattern with a bias in the extrusion direction for outerlayers and a preferential orientation in the transverse direction for the middle layers. The mechanics of the processes has been analysed by a plasticity approach for solid state extrusion, and by using variable wall boundaries for the melt extrusion analysis. The extrusion pressure predicted by the analysis compares very well with the values measured experimentally.
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5

Wang, Xinting. "NEW SYSTEMS FROM THE FORCED ASSEMBLY CO-EXTRUSION PROCESS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1607104088439343.

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6

Hurysz, Kevin Michael. "Paste mechanics for fine extrusion." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/19424.

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7

Handlos, Agnita A. "The processing of microcomposites based on polypropylene and two thermotropic liquid crystalline polymers in injection molding, sheet extrusion, and extrusion blow molding." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-164735/.

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8

Rongzhi, Huang. "MULTILAYER CO-EXTRUSION AND TWIN-SCREW COMPOUNDING OF POLYMERIC ELASTOMER SYSTEMS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1404864078.

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9

Shishesaz, Mohammad Reza. "Structure-property relationships in extruded plastics foams." Thesis, Brunel University, 1989. http://bura.brunel.ac.uk/handle/2438/5404.

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Physical properties and morphology of extruded semicrystalline polymers can be significantly affected by modification and change in die design and melt viscosity of the molten polymer. Further modifications to physical properties (i.e. density and open cell fraction) of foamed material occur, following the modification of melt viscosity by melt blending of polypropylene and high density polyethylene). The main object of this research project was to carry out a systematic examination of rheological properties of polymer/gas mixture, affect of die design, polymer molecular weight (melt viscosity), and processing conditions on density, open cell fraction, cell morphology (i.e. cell size and cell size distribution) and micromorphology of polyolefin foams. Also attention was given to method of stabilisation of extruded foam, where, it was found support of the extrudated foam (by adding a specially designed die adapter to the end of the die) prior to entering the cooling tank could result not only to a specimen with uniform cross section, but also due to drop in melt temperature, the cell walls are to some extent rigidized, hence, the collapse of bubbles are limited. From commercial point of view control of cell collapse, density and open cell fraction, will make these foamed materials valuable for their filtration characteristics. Microstructural analysis of polypropylene (unfoamed state) by X-ray diffraction and Differential Scanning Calorimetry revealed 13-spherulites are only formed in skin layer, and beneath the thickness of 500 pm from the surface, the crystal structure of this polymer is only consist of B-spherulites. On the other hand, the chemical blowing agent (Hydrocerol CF-20), was found to have nucleating affect on microstructure of polypropylene, where, it has resulted in reduction of size of spherulites together with a drop in recrystallisation temperature and formation of P and a spherulites through the thickness of extrudated foam. The foregoing chemical blowing agent was found to have no significant affect on the crystal structure of the high density polyethylene.
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10

Uvieghara, Mathias N. "The Effect of Deborah Number and Aspect Ratio on the Film Casting of LLDPE Melts." Fogler Library, University of Maine, 2004. http://www.library.umaine.edu/theses/pdf/UviegharaMN2004.pdf.

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11

Parpart, Dawn Allison. "PET/nylon 66 polymer blends and carpet recycling." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/9139.

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12

林肖明 and Chiu-ming Lam. "Visualization studies on the dynamic processing characteristics of conventional full-flighted and barrier type single-screws." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31222845.

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13

Huang, Keyuan. "Decrosslinking of Crosslinked Polyethylene via Ultrasonically Aided Extrusion." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1428160856.

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14

Sanyal, Yoddhojit 1969. "Synthesis and analysis of a microcellular plastics extrusion system for insulation of fine wires." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/50529.

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Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998.
Includes bibliographical references (leaves 138-140).
This thesis deals with analytical and experimental work performed on the extrusion of microcellular plastics with cell sizes of 20 microns or less and cell densities of about a billion cells per cm3. An analytical model of cell nucleation and cell growth during extrusion was developed. This model predicts the nucleation rate by taking into account Gibbs free energy change due to phase separation, as well as surface energy, in binary systems (such as polymer/gas mixtures). The cell growth kinetics during extrusion is also studied under some limiting cases. The analysis shows that due to the simultaneous occurrence of cell nucleation and cell growth during extrusion, these two phenomena are coupled and compete with each other for the gas dissolved in the polymer. With the aid of this model the important extrusion parameters affecting the microstructure of the foam were identified. An order-of-magnitude prediction of cell size, cell density and foam void fraction were made based on realistic numerical values of these parameters. The next phase of the project consisted of using the analytical model and Axiomatic Design Theory to design a tandem extrusion system for wire coating. Satisfaction of the Independence Axiom showed that the process was controllable. Preliminary analysis of the Information Axiom indicated that the system would be stable. Experiments were performed over a range of conditions to determine their effects on the final wire insulation diameter and capacitance. The experimental results were compared to the analytical predictions to further verify the validity of the model as well as to determine its limitations.
by Yoddhojit Sanyal.
Sc.D.
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15

Alemaskin, Kirill. "ENTROPIC MEASURES OF MIXING IN APPLICATION TO POLYMER PROCESSING." Case Western Reserve University School of Graduate Studies / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=case1098397260.

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16

Repka, Michael Andrew. "Physical-mechanical and chemical properties of topical films produced by hot-melt extrusion /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.

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17

Barnes, Christopher Mark. "The cooling and solidification of thermoplastic polymers : an experimental and theoretical study of the cooling and solidification of thermoplastic polymers in various blow moulding and pipe extrusion situations." Thesis, University of Bradford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236460.

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18

Sabol, Edward A. "The development of a dual extrusion blending process and composites based on thermotropic liquid crystalline polymers and polypropylene." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/40650.

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19

Novák, Jakub. "Návrh a realizace vytlačovací hlavy a návazných členů pro vytlačování kruhových plastových profilů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230993.

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In this work is developed a proposal for extrusion head for extruding plastic wires of small diameter. There is a new conceptual design of cooling, which allows shape extruded products already in the extrusion head and thereby eliminates the need for large cooling tanks. To determine the optimal design is used software named Virtual Extrusion Laboratory, which is used in practice for the simulation of the extrusion process. Then it is experimentally determined behavior of plastic material, when the temperature of the melt in the extrusion head is reduced.
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20

Gao, Xiang. "Ultrasound Assisted Extrusion and Properties of Polycarbonate/Carbon Nanotubes Composites and Cast Films." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1493394163570255.

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21

Pandey, Vivek. "Extensional Mixing Elements for Improved Dispersive Mixing in Extrusion Operations." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1591698465031928.

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22

Zhong, Jing. "Ultrasonically aided extrusion in preparation of polymer composites with carbon fillers." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1460413630.

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23

Harris, Patrick James. "LAYERED POLYMERIC SYSTEMS:NEW PROCESSING METHODS AND NOVEL MECHANICAL DESIGN IN EXTENSIONAL RHEOLOGY." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1410544432.

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24

Arroyo-Huayta, Carlos, Sebastian Cruces-Raimudis, Gino Viacava-Campos, Claudia Leon-Chávarri, and Daniel Aderhold. "Model to improve the efficiency in the extrusion area in a manufacturing sme of the industrial plastic sector based on smed, autonomous maintenance and 5s." Springer, 2021. http://hdl.handle.net/10757/656029.

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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.
At present, companies in the Peruvian plastic sector have an average capacity utilization indicator of 71.45%. However, in Peru many SMEs are with 50% well below this indicator. After a study performed in a representative company of the Peruvian plastic sector, the causes of low efficiency in resource utilization were determined through a problems tree and a Pareto analysis. These causes are failures, reprocesses and Setup times in the extrusion machines, taking around 1008 h a year to solve these problems. This article proposes a model to improve efficiency, integrating Lean Manufacturing tools such as 5s, SMED, and autonomous maintenance. The first one was used as a support tool, while SMED was used to reduce the configuration time and autonomous maintenance to reduce the failures number and the reprocesses number. The model was validated through a case study, obtaining as results the reduction of the setup time by 50%, breakdowns by 50% and reprocesses by 60%.
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25

Mehta, Bhavin V. "Computer aided design and analysis of polymer flows in three dimensional extrusion dies." Ohio : Ohio University, 1992. http://www.ohiolink.edu/etd/view.cgi?ohiou1173753025.

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26

Cengiz, Filiz. "Preparation And Characterization Of Recycled Polypropylene Based Nanocomposites." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609873/index.pdf.

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The aim of this study was to improve the mechanical properties of a recycled grade polypropylene. Polymer blends and nanocomposites were prepared by melt compounding method in a twin screw extruder. Cloisite®
15A, Cloisite®
25A and Cloisite®
30B were used as organoclays, and ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) and maleic anhydride grafted polypropylene (PP-MAH) were used as compatibilizers. The effects of additive concentrations, types of organoclays and compatibilizers, processing conditions, and the compatibilizer to organoclay ratio on the morphology and mechanical, thermal and flow properties were investigated. Organoclay loading over 2 wt% prevented the intercalation mechanism and material properties, even in the presence of compatibilizer, as a consequence of large clay agglomerate formation. E-MA-GMA compatibilizer improved the intercalation ability of the polymer
however a substantial increase in mechanical properties was not obtained. PP-MAH is found to be a better compatibilizer. Processing conditions significantly affected both mechanical properties and morphology. When the processing temperature was decreased and screw speed was increased simultaneously, tensile and impact properties were improved owing to enhanced shear and dispersive forces. TEM analysis revealed that intercalated and delaminated structures were formed with the addition of PP-MAH compatibilizer. In addition to that, as the ratio of PP-MAH to organoclay was increased, more effective dispersion of organoclay was observed and hence resultant improvements in both tensile and impact properties were greater at compatibilizer to organoclay ratio of three. Cloisite®
15A exhibited the highest improvements in mechanical properties, although the degree of organoclay dispersion was better for Cloisite®
25A and particularly for Cloisite®
30B. Melt flow index values were lower compared to pure recycled polypropylene in the presence of organoclay and compatibilizers. DSC analysis indicated no significant change in the melting behavior of the matrix materials.
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27

Yeniova, Canan Esma. "Impact Modified Polystyrene Based Nanocomposites." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610306/index.pdf.

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Polystyrene, PS, is a preferable polymer in industry, but, its brittle characteristic restricts its utilization. The aim of this study is to improve the impact strength of PS by the help of elastomeric materials SEBS-g-MA and E-BA-GMA. In order to prevent the reduction in the tensile strength of the materials, three different types of organic montmorillonites, MMT, (Cloisite®
30B, 25A and 15A) were used as fillers. Nanocomposite preparation was performed in a co-rotating twin screw extruder. Initially elastomer and organoclay contents were kept at 5wt% and 1-2wt% respectively. Well dispersed silicate layers were obtained for the nanocomposite containing SEBS-g-MA and Cloisite®
25A owing to the high viscosity of SEBS-g-MA and the solubility of polystyrene end block of SEBS with PS matrix. Owing to higher hydrophobicity of Cloisite®
15A a better dispersion was expected compared to Cloisite®
25A, but, it was concluded that two long aliphatic tails of Cloisite®
15A limited the access of polymer chains to the clay surface. The desired impact strength values could not be achieved by using 5wt% elastomeric materials
therefore, it was decided to increase the SEBS-g-MA content up to 15, 20, 30 and 40wt%. With increasing elastomer content, increasing average elastomer domain size was obtained. Also, it was observed that with the addition of organoclay, the elastomeric domain size increases since the clay particles reside in the elastomer phase and at the interphase between elastomer and PS. The mechanical test results showed that the nanocomposites containing 15 and 20wt% SEBS-g-MA have the optimum average domain size that results in better impact strength values without deteriorating tensile properties.
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28

Mert, Miray. "Impact Modified Nylon 66-organoclay Nanocomposites." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608112/index.pdf.

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PA 66 nanocomposites and PA 66 blends were prepared using Cloisite 15A, Cloisite 25A and Cloisite 30B as organoclays and Lotader 2210 (E-BA-MAH), Lotader AX8840 (E-GMA) and Lotader AX8900 (E-MA-GMA) as impact modifiers. The effects of the composition, types of the components and the addition order of the nanocomposites on the morphology, mechanical, flow and thermal properties were investigated. Melt compounding step was carried out twice in a co-rotating twin-screw extruder. This was called as All-S mixing sequence when all the components were melt mixed, simultaneously. The concentration of the elastomer was determined as 5 wt% and the organoclay as 2 wt% to minimize agglomeration of the organoclay and decrease in the mechanical properties. The components which exhibited the best mechanical results and organoclay delamination in All-S mixing sequences were compounded by using different addition orders. Substantial increases were not observed in the tensile, impact, flexural and hardness test results of the nanocomposites compared to the polymer matrix that was twice extruded. Addition order of the components affected the properties of the nanocomposites and dispersion of the elastomeric domains and the organoclay. The best mechanical test results were obtained for All-S mixing sequence of (PA 66-15A-2210). The degree of organoclay dispersion is better in Cloisite 15A and Cloisite 25A containing nanocomposites than the ones which have Cloisite 30B. Low melt flow index values aided dispersion of the organoclay whereas the slight changes in the crystallinity did not significantly contribute to the changes in the mechanical properties of the nanocomposites or the blends.
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29

Baena, Johanna. "PROCESSING AND KINETIC STUDIES OF THE REACTIVE BLENDS OF POLY(VINYL CHLORIDE) AND THERMOPLASTIC POLYURETHANES." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1163727625.

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30

Kretschek, David. "Desenvolvimento de um cabeçote de extrusão por êmbolo para polipropileno granulado visando a manufatura aditiva." Universidade Tecnológica Federal do Paraná, 2012. http://repositorio.utfpr.edu.br/jspui/handle/1/890.

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CAPES
Um dos processos de manufatura aditiva mais popularesse baseia na fusão e deposição do material. O princípio de funcionamento aplicado nestes equipamentos restringe o fornecimento de matéria-prima, principalmente no mercado nacional, e a gama de materiais aplicáveis. O desenvolvimento de um equipamento capaz de processar o material na forma granulada contribuiria para a popularização do processo e para a ampliação da gama de materiais disponíveis a serem utilizados. Este trabalho descreve o desenvolvimento de um cabeçote de extrusão capaz de processar polipropileno granulado e extrudá-lo em forma de filamento contínuo e controlado. Este foi projetado de forma a reduzir o efeito da degradação sobre o material. Experimentos foram conduzidos a fim de caracterizar o comportamento dimensional dos filamentos gerados e assim permitir o seu melhor controle. A degradação do material no interior do cilindro aquecido foi avaliada por ensaios de espectroscopia no infravermelho e de tração em amostras de filamentos. Os resultados dos experimentos de extrusão mostraram que os filamentos apresentam variação de vazão ao longo do comprimento extrudado, sendo que a sua largura aumenta até atingir um patamar onde estabiliza. Os ensaios de espectroscopia mostram ocorrer degradação dentro do cilindro aquecido, mas os efeitos negativos sobre a resistência mecânica dos filamentos são menos acentuados quando empregando o cabeçote projetado. Concluiu-se que o princípio de extrusão por êmbolo com alimentação granulada é viável, necessitando, no entanto, desenvolver mecanismos de controle da extrusão mais adequados ao processo.
One of the most popular additive manufacturing processes is based on fuseddeposition of the material. The principleapplied to these machines makes difficult to find suppliers of raw materials, especially in brazilian market, and narrow the variety of materials applicable. The development of equipment able to process the material in the granular form will contribute to the process popularization and extension of available material to be used. This work describes the development of an extrusion head capable to process polypropylene granules and extrudeit as continuous and controlled filament. The extrusion head was designed in order to minimize the volume of material to be fused and reduce the effect of material degradation. Experiments were conducted to characterize the dimensional behavior of the filaments generated and thus allow its better control. The material degradation inside the extrusion head was assessed by infrared spectroscopyand its negative effects over filaments strength by tensile tests.The results of the extrusion experiments showed that the filaments have flow variation along the extruded length, following an increasing curve until a value where its average stabilizes. Spectroscopy showed that degradation occurs inside the heated cylinder, but its negative effects on material strength are less intense when using the designed extrusion head. It was concluded that the extrusion plunger principle with granulated feeding is viable for Additive Manufacturing, requiring, however, better control mechanisms of the extrusion to enable the manufacture of uniform and cohesive parts.
5000
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31

Alyamac, Elif. "Impact Modified Poly(ethylene Terephthalate)-organoclay Nanocomposites." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605092/index.pdf.

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This study was conducted to investigate the effects of component concentrations and addition order of the components, on the final properties of ternary nanocomposites composed of poly(ethylene terephthalate), organoclay, and an ethylene/methyl acrylate/glycidyl methacrylate (E-MA-GMA) terpolymer acting as an impact modifier for PET. In this context, first, the optimum amount of the impact modifier was determined by melt compounding binary PET-terpolymer blends in a corotating twin-screw extruder. The amount of the impact modifier (5 wt. %) resulting in the highest Young&rsquo
s modulus and reasonable elongation at break was selected owing to its balanced mechanical properties. Thereafter, by using 5 wt. % terpolymer content, the effects of organically modified clay concentration and addition order of the components on ternary nanocomposites were systematically investigated. Mechanical testing revealed that different addition orders of the materials significantly affected mechanical properties. Among the investigated addition orders, the best sequence of component addition (PI-C) was the one in which poly(ethylene terephthalate) was first compounded with E-MA-GMA. Later, this mixture was compounded with the organoclay in the subsequent run. Young'
s modulus of not extruded pure PET increased by 67% in samples with 5 wt. % E-MA-GMA plus 5 wt. % clay loading. The highest percent elongation at break was obtained as 300%, for the addition order of PI-C, with 1 wt. % clay content, which is nearly 50 fold higher than that obtained for pure PET. In X-ray diffraction analysis, extensive layer separation associated with delamination of the original clay structure occurred in PI-C and CI-P sequences with both 1 and 3 wt. % clay contents. X-ray diffraction patterns showed that, at these conditions exfoliated structures resulted as indicated by the disappearence of any peaks due to the diffraction within the consecutive clay layers.
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32

Ersu, Dilek. "Preparation And Characterization Of Nanocomposites With A Thermoplastic Matrix And Spherical Reinforcement." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/3/12607447/index.pdf.

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The aim of this study is to investigate the effects of compatibilizers, fumed silica and mixing order of components on morphological, thermal, mechanical and flow properties of LDPE/Fumed silica nanocomposites. As compatibilizer(Co)
ethylene/n-butyl acrylate/maleic anhydride (E-nBA-MAH), ethylene/glycidyl methacrylate (E-GMA) and ethylene/methyl acrylate/glycidyl methacrylate (E-MA-GMA) Lotader®
resins
as silica Cab-o-sil®
M5 fumed silica were used. All samples were prepared by means of a lab scale co-rotating twin screw extruder and injection molded into standard samples. In the first step, individual effects of filler and compatibilizers were studied in binary systems with LDPE. Then, keeping the amount of compatibilizer constant at 5%, ternary nanocomposites were prepared by adding 2 or 5% of fumed silica using different component mixing orders. Among investigated mixing orders, mechanical test results showed that the best sequences of component addition are FO1 [(LDPE+Co)+M5] and FO2 [(LDPE+M5)+Co] mixing orders. Considering the compatibilizers, E-nBA-MAH terpolymer showed the highest performance in improving the mechanical properties, E-GMA copolymer also gave satisfactory results. According to the DSC analysis, since addition of fumed silica and compatibilizer does not influence the crystallization behavior of the compositions, it is concluded that, neither fumed silica nor any of the compatibilizers have nucleation activity on LDPE. MFI test results showed that, addition of fumed silica increases the melt viscosity, decreasing MFI values of samples. This change seems to be directly proportional to fumed silica amount.
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33

Altan, Cansu. "Preparation And Characterization Of Glass Fiber Reinforced Poly(ethylene Terephthalate)." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605216/index.pdf.

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Glass fiber reinforced poly(ethylene terephthalate), GF/PET has excellent potential for future structural applications of composite materials. PET as a semi-crystalline thermoplastic polyester has high wear resistance, low coefficient of friction, high flexural modulus and superior dimensional stability make it a versatile material for designing mechanical and electromechanical parts. Glass fibers are currently used as strength giving material in structural composites because of their high strength and high performance capabilities. In order to obtain high interfacial adhesion between glass fiber and polymer, glass fibers are treated with silane coupling agents. The objective of this study is to produce GF/PET composites with varying glass fiber concentration at constant process parameters in a twin screw extruder. Also, by keeping GF content constant, it is aimed to observe the effects of process parameters such as screw speed and feed rate on structural properties of the composites. Another objective of the study is to investigate the influence of different coupling agents on the morphological, thermal and mechanical properties and on fiber length distributions of the composites. Tensile strength and tensile moduli of the GF/PET composites increased with increasing GF loading. There was not a direct relation between strain at break values and GF content. The interfacial adhesion between glass fiber received from the manufacturer and PET was good as observed in the SEM photograps. Degree of crystallinity values increased with the addition of GF. Increasing the screw speed did not affect the tensile strength of the material significantly. While increasing the feed rate the tensile strength decreased. The coupling agent, 3-APME which has less effective functional groups than the others showed poor adhesion between glass fiber and PET. Therefore, lower tensile properties were obtained for the composite with 3-APME than those of other silane coupling agents treated composites. Number average fiber length values were reduced to approximately 300&
#61549
m for almost all composites prepared in this study.
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34

Kilinc, Mert. "Production And Characterization Of Boron-based Additives And The Effect Of Flame Retardant Additives On Pet-based Composites." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610635/index.pdf.

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For the aim of production of poly(ethylene terephthalate), PET based flame retardant composites
boron based flame retardant additives, 3.5 mole hydrated zinc borate and boron phosphate were synthesized. Zinc borate was synthesized with the reaction of boric acid and zinc oxide in both laboratory and pilot scale reactors. Effects of reaction parameters on kinetics of reaction and final product particle size were evaluated. Boron phosphate was synthesized via dry, wet and microwave methods. In addition to the synthesized flame retardant additives, several non-halogenated flame retardant additives, which were commercially available, were also used. Composites were prepared using twin screw extruder and molded by injection molding, followed by characterization in terms of flame retardancy behavior, mechanical and thermal properties, and morphologies. Based on the results of first stage experiments, aiming to determine effective additives, different amounts and combinations of triphenyl phosphate, triphenyl phosphine oxide, zinc borate and microwave produced boron phosphate were chosen and used in PET matrix. Flame retardancy of the composites were determined by conducting horizontal burning rate and limiting oxygen index (LOI) tests. Smoke emissions during fire were also measured. According to the LOI test results, LOI of neat PET was determined as 21%, and with the addition of 5% boron phosphate and 5% triphenyl phosphate together, LOI was increased up to 36%. The smoke density analysis results implied that, boron phosphate was a successful smoke suppressant for PET matrix. In addition to flammability properties, tensile and impact properties of the composites were also improved with flame retardant additives and expecially with the addition of triphenyl phosphate.
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35

Feng, Jingxing. "Transport Phenomena in Polymeric Blends and Multilayer Films." Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1548202751756984.

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36

Tijen, Seyidoglu. "Purification And Modification Of Bentonite And Its Use In Polypropylene And Linear Low Density Polyethylene Matrix Nanocomposites." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612204/index.pdf.

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The potential use of Resadiye/Tokat bentonite as a reinforcement in polypropylene (PP) and linear low density polyethylene (LLDPE) polymer matrix nanocomposites filler was investigated. At first, organoclays (OC) were prepared by cation exchange reaction (CER) between the raw bentonite (RB) and three quaternary ammonium salts with long alkyl tails (QA): hexadecyl trimethyl ammonium bromide [HMA] [Br], tetrabutyl ammonium tetrafluoroborate [TBA] [BF4], tetrakisdecyl ammonium bromide [TKA] [Br] and one quaternary phosphonium (QP) salt: tetrabutyl phosphonium tetrafluroborate [TBP] [BF4]. Characterization of resulting materials by XRD, TGA, FTIR and chemical analysis confirmed the formation of organoclays. Ternary composites of PP/organoclay/ maleic anhydride grafted polypropylene (MAPP) were prepared with two different grades of PPs in a co-rotating twin screw extruder. Composites prepared with these organoclays and PPs showed microcomposite formation. In the second part of the study, raw bentonite was purified by sedimentation, and characterization of purified bentonite (PB) by XRD, cation exchange capacity (CEC) measurement and chemical analysis (ICP) confirmed the success of purification method. PB was then modified with two QA`s: dimethyl dioctadecylammonium chloride [DMDA] [Cl], tetrakis decylammonium bromide [STKA] [Br] and one QP: tributyl hexadecyl phosphonium bromide [TBHP] [Br]. Organoclays from PB were used with the PP with lower viscosity, and ternary nanocomposites (PP/Organoclay2/MAPP5) were prepared in the extruder followed by batch mixing in an intensive batch mixer. Use of DMDA and TBHP OCs resulted in nanocomposite formation, while STKA resulted in microcomposite formation as observed by XRD and TEM. Young`s modulus and yield stress of the samples were enhanced through nanocomposite formation. In the last part of the study, ternary composites of LLDPE/Organoclay/ compatibilizer, a random terpolymer of ethylene, butyl acrylate and maleic anhydride (E-BA-MAH, Lotader®
3210), were prepared by melt compounding in the batch mixer at two different clay concentrations (2 and 5 wt %) and fixed compatibilizer/organoclay ratio (&alpha
=2.5). A commercial organoclay, I34, was also used in LLDPE based nanocomposites to make a comparison. XRD and TEM analyses of the compounds prepared by DMDA and TBHP showed mixed nanocomposite morphologies consisting of partially intercalated and exfoliated layers. Young`s modulus and tensile strength of nanocomposites prepared with DMDA and TBHP showed generally higher values compared to those of neat LLDPE, while results were the highest in the composites prepared with commercial organoclay I34. Parallel disk rheometry was used as a supplementary technique to XRD, TEM and mechanical characterizations, and it was shown to be a sensitive tool in assessing the degree of dispersion of clay layers in the polymer matrix.
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37

Agrawal, Akash. "Examining the Effectiveness of Different Mixing Elements in the Twin Screw Compounding of Liquid Crystal Polymer and Polypropylene." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1512742062745962.

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38

Pham, Thuy Linh. "Plastification en injection des polymères fonctionnels et chargés." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-01015839.

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L'objectif principal de la thèse est de modéliser et visualiser les phénomènes de plastification des polymères dans le procédé d'injection-moulage. Dans les procédés de transformation des polymères par un système vis-fourreau (extrusion, injection), la plastification est l'étape durant laquelle le polymère originellement à l'état solide est graduellement fondu et homogénéisé par le chauffage externe et l'action mécanique de la friction contre les parois de l'outillage et du cisaillement. Cette étape est capitale dans la maîtrise technique et économique du procédé, en termes d'homogénéité thermique, de mélange des charges et de temps de séjour du polymère. Nous envisageons de visualiser et modéliser l'ensemble du processus de plastification dans les monovis d'injection. Afin de comprendre et de mesurer cette étape, nous avons conçu, validé et réalisé un fourreau à fenêtres. Ce système se compose de trois fenêtres de visualisation, insérées dans un fourreau en acier usiné par électroérosion. Le comportement mécanique de cet assemblage a été analysé par simulation numérique, sous différentes sollicitations thermiques, pressions et contraintes. L'hétérogénéité des matériaux de structure (acier - verre) a fait apparaître des problèmes potentiels de fuites, de fragilité qui ont été pris en compte dans la conception. Ce fourreau à fenêtres nous permet de visualiser et de suivre à l'aide des caméras scientifiques, les différents états du polymère une fois introduit dans l'ensemble vis-fourreau. Les résultats confirment les hypothèses théoriques de la plastification. Certains sont mis en évidence, comme l'existence d'un lit solide adossé à l'arrière du filet de la vis, ainsi que son évolution par rapport à la vitesse de rotation de la vis, ou l'apparition des films fondus entre le filet de la vis et le lit solide, et entre la paroi du fourreau et le lit solide. Certains sont par contre à vérifier par d'autres expériences, comme par exemple : l'apparition de la rupture du lit solide quelle que soit la vitesse de rotation de la vis, la valeur de la vitesse du lit solide par rapport à la vitesse de rotation de la vis. Nous souhaitons aussi, grâce à ce système "fourreau transparent", pouvoir étudier, modéliser et visualiser les aspects de dispersion et de mélange des charges (traceurs, pigments, mélange maître) au sein de la matrice polymère à l'état solide ou fondu.
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39

Vanin, Mirela. "Estudo das condições de extrusão reativa e suas influencias na compatibilização e propriedades da mistura poli (tereftalato de etileno) (pet)/policarbonato (pc)." [s.n.], 1998. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266473.

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Orientador: Chang Tien Kiang
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: o estudo de misturas poliméricas têm crescido bastante devido à possibilidade de se obter materiais de alta performance. Muitos são os estudos sobre a mistura Poli (tereftalato de etileno)(PET)/Policarbonato(PC) , donde se tem que, esta mistura é termodinamicamente imiscível, mas com possibilidade de se conseguir compatibilizar os polímeros quando misturados no estado fundido, devido a ocorrência de reações de transesterificação. Além disso, a eficiência destas reações podem ser influenciadas pelos parâmetros de processamento. Este trabalho visa o estudo da mistura PET/PC, objetivando combinar a alta resistência térmica e mecânica do PC, com a grande utilidade do PET como polímero de engenharia. As amostras da mistura PET/PC foram confeccionadas por extrusão reativa no estado fundido, variando parâmetros de processamento como: tempo total de processamento e de cisalhamento, concentração de componentes de mistura, emprego e concentração de catalisador e reprocessamento, no equipamento Mini Max Molder e em extrusora dupla rosca. As amostras obtidas foram caracterizadas por: Viscosidade intrínseca, notando-se a possível ocorrência de reações de degradação no emprego de catalisador; Microscopia Eletrônica de Varredura, verificando-se que o aumento do tempo total de processo e do cisalhamento contribuíram para melhorar a dispersão das fases; Infravermelho por Transformada de Fourier, donde verificou-se que a eficiência das reações de transesterificação foi aumentada com o aumento do tempo de processo e de cisalhamento; e análise mecânica, por Análise Dinâmico Mecânica que permitiu observar tendência à miscibilidade da mistura PET/PC devido ao aparecimento de uma única Tg, na análise dos resultados
Abstract: The studies on polymeric mixtures increased considerably due to the possibilities of obtaining high performance materials. Many of them are about the Poly (ethylene terephthalate) (PET)/ Polycarbonate (PC) mixture, which is thermodynamically immiscible, but potentially compatible when the polymers are mixed in the molten state due to transesterification reactions. Besides, the efficiency of these reactions can be influenced by the processing parameters. This study is aimed at studying PET/PC mixture by combining the PC high mechanical and thermal resistance and the usefulness of PET as an engineering polymer. The PET/PC mixture samples were obtained by reactive extrusion in the molten state, varying processing parameters such as: total processing time, shearing time, concentration of the mixture components, utilization of a catalyzer, catalyzer concentration and reprocessing in a Mini Max Molder equipment, as well as varying screw speed in a twin-screw co-rotating extruder. The samples obtained were characterized by: intrinsic viscosity, observing the possible degradation reactions in the utilization of the catalyzer; Scanning Electron Microscopy, verifying if the increase in the processing and shearing time contributed to improve the phase dispersion; Fourier Transformed Intrared analysis was utilized to confirm the efficiency of the transesterification reactions due to the increase in the process time and shearing time; Dynamic Mechanical Analysis showed that the PET/PC mixtures were compatibilized with the appearance of a single Tg
Mestrado
Ciencia e Tecnologia de Materiais
Mestre em Engenharia Química
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40

Rizvi, Ghaus Muhammad. "Extrusion foaming of plastic/wood-fiber composites using a chemical blowing agent." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0020/MQ45623.pdf.

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41

Desa, Stella. "Quality monitoring of recycled plastic waste during extrusion, in-line particle detection." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1995. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ45466.pdf.

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42

Chan, David Tai-Wai. "Analysis of molecular orientation and internal stresses in plastic sheet extrusion process /." The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487596307358216.

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43

Ng, Chin Yee. "Extrusion of microcellular plastic using a tandem foaming system : design, fabrication and experimentation." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10283.

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44

Mizera, J., P. Maj, and B. Adamczyk-Cieslak. "Comparison of Grain Refinement in Selected Materials Subjected to Hydrostatic Extrusion." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35600.

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The subject of this study was to examine and compare the impact of intense hydrostatic extrusion on grain refinement in three different alloys: duplex stainless steel, commercially used aluminum alloy (6060) and Ag-Cu12 alloy. As a result of the process grain sizes from 370 nm to 90 nm were obtained in aluminum and duplex steel. To analyze the of hydrostatic on mechanical properties tensile tests were also carried out. The highest grain refinement (70 nm) and yield strength increase (over 300%) was observed in duplex steel af-ter hydrostatic extrusion. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35600
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45

Martins, Milene Heloisa. "Formulações de misturas de polipropileno pos-consumo e virgem para processamento por injeção." [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248848.

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Orientador: Mauro-Aurelio De Paoli
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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46

Yapici, Guney Guven. "Severe plastic deformation of difficult-to-work alloys." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/531.

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The present work aims to reveal the microstructural evolution and post-processing mechanical behavior of difficult-to-work alloys upon severe plastic deformation. Severe plastic deformation is applied using equal channel angular extrusion (ECAE) where billets are pressed through a 90o corner die achieving simple shear deformation. Three different materials are studied in this research, namely Ti-6Al-4V, Ti-6Al-4V reinforced with 10% TiC and AISI 316L stainless steel. Microstructure and mechanical properties of successfully extruded billets were reported using light microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), tension and compression experiments and microhardness measurements. The effects of extrusion conditions (temperature and processing route) on the microstructure and mechanical properties are investigated. The underlying mechanisms responsible for observed mechanical behaviors are explored. It is seen that ECAE shear deformation leads to refinement in α plates and elimination of prior β boundaries in Ti-6Al-4V. Decreasing extrusion temperature and increasing number of passes decreases α plate size and grain size. Refined α grain size leads to a significant increase in tensile and compressive flow stresses at room temperature. Texture produced by ECAE has a pronounced effect on mechanical properties. Specifically it leads to tension/compression asymmetry in flow strengths and strain hardening coefficients may be described by the activation of differing slip systems under tension and compression loading. ECAE of Ti-6Al-4V+10%TiC samples also improved mechanical properties due to α plate size refinement. Nevertheless, further extrusion passes should be carried out for tailoring reinforcement size and distribution providing optimum strength and ductility. ECAE deformation of AISI 316L stainless steel at high homologous temperatures (0.55 to 0.60 Tm) results in deformation twinning as an effective deformation mechanism which is attributed to the effect of the high stress levels on the partial dislocation separation. Deformation twinning gives rise to high stress levels during post-processing room temperature tension and compression experiments by providing additional barriers to dislocation motion and decreasing the mean free path of dislocations. The highest tensile flow stress observed in the sample processed at 700 oC following one pass route A was on the order of 1200 MPa which is very high for 316L stainless steel. The ultimate goal of this study is to produce stabilized end microstructures with improved mechanical properties and demonstrate the applicability of ECAE on difficult-to-work alloys.
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47

Коротка, Валерія Олександрівна. "Екструзійний агрегат з модернізацією черв‘яка." Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/41797.

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Метою розробки і проектування є аналітичні, проектувальні розрахунки з використанням відомих методів, нормативних документів, комп’ютерних програм. Проектування та розробка екструзійного агрегату виконана на основі патентних досліджень, вивчення науково-технічної літератури, інженерно-технічних розрахунків та аналітичного огляду. Виконане наступне: -проведені інженерні розрахунки для проектування та розробки ееструдера,згідно з технічним завданням; -вивчено принцип роботи екструзійного агрегату для плівкового пластикату,проаналізовані технічні параметри та характеристики; -на основі патентного дослідження модернізовано черв’як екструзійного агрегату; -розроблено та спроектовано екструзійний агрегат з модернізованим черв’яком для плівкового пластикату;
The purpose of development and design is analytical, design calculations using known methods, regulations, computer programs. The design and development of the extrusion unit is performed on the basis of patent research, study of scientific and technical literature, engineering and technical calculations and analytical review. The following was done: -engineered calculations for the design and development of eestruder, in accordance with the terms of reference; - the principle of operation of the extrusion unit for film plastic was studied, technical parameters and characteristics were analyzed; - on the basis of patent research the worm of the extrusion unit is modernized; - developed and designed an extrusion unit with an upgraded worm for film plastic;
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48

Silva, Reyes Alfredo Jeampiere, and Castro Rosa Fernanda Salas. "Application of Lean Techniques to Reduce Preparation Times: Case Study of a Peruvian Plastic Company." Research India Publications, 2017. http://hdl.handle.net/10757/622530.

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This article examines the problem of an increase in product returns for a company that produces plastic films for flexible packaging. Among the factors that have resulted in the increase of returned products are defects in the films caused by the poor manipulation of materials and, above all, the hard point in the coils caused by excessive extruder preparation time, causing the extrusion head to overheat as well as uneven extrusion. Extrusion is a key process in the production of plastic materials as it transforms polypropylene and additives into plastic sheets. The delay in the preparation time caused by machine operators leads to the overheating of the extrusion head and, therefore, defective products that are ultimately returned to the company by customers. In order to confront this problem, a proposal was developed using the SMED tool of Lean Manufacturing in order to reduce the preparation time of the extruder and to increase the productivity of the company. For the validation of the proposal, we simulated the system to determine the resulting reduction in extruder preparation time.
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49

Zhang, Haiou. "Extrusion of fine-celled plastic/wood-fiber composite foams using CO¦2 as a blowing agent." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0027/MQ50426.pdf.

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50

Nascimento, Jefter Fernandes do. "Estudo da processabilidade e da caracterização do Poli (acido 3-hidroxibutirico) - PHB obtido a partir da cana-de-açucar." [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266531.

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Orientadores: Lucia Helena Innocenti Mei, Jose Augusto Marcondes Agnelli
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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