Dissertations / Theses on the topic 'Polypropylene liner'
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McCallum, Tara J. "Properties and foaming behaviour of thermoplastic olefin blends based on linear and branched polypropylene." Thesis, Kingston, Ont. : [s.n.], 2007. http://hdl.handle.net/1974/872.
Full textRao, Nikhil. "Interfacial tension, blending and morphology of linear low-density polyethylenes with polypropylene." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ40097.pdf.
Full textNelson, Burke I. (Burke Irving). "Control of a polypropylene visbreaking process using an in-line process rheometer." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28499.
Full textThe rheometer was used as a viscosity sensor to provide feedback control for a polypropylene visbreaking process. A first order plus dead time model was used to model the process and the rheometer together, and typically had dead times of less than 60 s and a first order time constant of 15 s. Gain scheduling was incorporated into minimum variance and proportional-integral controllers to achieve closed-loop settling times of 200 s for viscosity setpoint changes and process disturbances.
Singh, Priti. "Morphology and rheology of binary blends of polypropylene and linear low density polyethylene." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0019/MQ49686.pdf.
Full textCardoso, Elisabeth Carvalho Leite. "Desenvolvimento de espumas a partir de misturas poliméricas de polipropileno linear (PP) e polipropileno de alta resistência do fundido (HMSPP)." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-22092011-085351/.
Full textFoamed polymers are future materials, with a comprehensive application field. They can be used in order to improve appearance of insulation structures, for example, or to reduce costs involving materials. This work address to Isotactic Polypropylene / High Melt Strength Polypropylene blends, for foams production. Rheological behavior of polymer melt, especially referring to viscosity in processing temperature, plays a decisive role in applications where dominates extensional flow, as in case of foaming. If the viscosity is very low, it will correspond to a low melt strength, as in case of linear homopolymer (Isotact PP), and the foam will be prejudiced, due to the impossibility of expansion. Otherwise, if the viscosity is very high, with a high melt strength, the foam will collapse immediately after its formation. In order to get foams with an homogeneous and defined cellular structure, there were accomplished blends, 50% in weight, between linear homopolymer (isotactic PP) and HMSPP, from PP modified as per gamma radiation, in acetylene environment and at a 12.5 kGy dosis. Extrusion process used a soluble foaming methodology, according to a processing/dissolution principle, which involves the dissolution of a Physical Blowing Agent (PBA), under 30 bar pressure, homogeneously mixed with polymeric melt. Extrusion conditions, that generally involve temperature, pressure and viscoelastic material flow control were experimentally investigated to define prevalent characteristics for producing foams. Nitrogen was the used PBA and process extrusion parameters were adapted to PP, HMSPP and their 50% in weight mixtures thereof. Major PP and HMSPP characteristics were obtained via melt Index and melt strength and thermal analyses (DSC/TGA), in order to make viable and to reproduce foaming as per extrusion process. Foams cellular morphology of PP, HMSPP and their 50% in weight mixtures thereof was investigated, with and without talc addition, as nucleating agent, by using Scanning Electron Microscope (SEM). Micrographs obtained pointed to closed cells foams, in which the pressure is kept during all cell formation stage, informing that closed cells foams are used in thermal insulation in Civil Construction and in thermal vials. Density analyses accomplished in foams produced in our work showed typical results for high density foams (320 to 800 kg/m3 range), around 500 kg/m3, used for wire and cables and for structural purposes (structural foams), by replacing wood, metals or solid plastics. Structural foams have high density (above 320 kg/m3) and cellular structures are specially composed by holes.
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.
Full text3210), 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.
CARDOSO, ELISABETH C. L. "Desenvolvimento de espumas a partir de misturas polimericas de polipropileno linear (PP) e polipropileno de alta resistencia do fundido (HMSPP)." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9485.
Full textMade available in DSpace on 2014-10-09T13:57:01Z (GMT). No. of bitstreams: 0
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Uzoukwu, E. Emeka. "Le Secteur pétrochimique dans le concept de développement global du Nigéria : les branches d'applications : polypropylene - linear alkyle benzene - carbon black." Paris, EHESS, 1990. http://www.theses.fr/1990EHES0018.
Full textThe petrochemical instrutory of nigeria that we propose to analyse poresents certain number of specificitises which indeed motivated our research. The apprehension of these principal specificities were observed by analysing the existence of a section of petrochemical industry in the context of general development of nigeria through the theory of "inductible industries" (industrie motrices). But at the same time our studies reveals through its analysis that the historical development of nigeria presents limits of pertinents condition of this theory. Withen petrochemical industry itself, the major concept of calculation * of linkage and induction effect show corresponding application. * on the level of general development of nigeria, the concept of "inductibility" or "linkage" industires meet lots of handicorp in its methodological application, in the sense that the other other concept of the theory : that of "triangulation" does not have its objective correspondance in the strategic planing, by nigerian decision makers. Thus nigeria did not opte for this concept as to it's development, not for the fact that it does not have a modern administrative society, nor was it for the fact it's decision. .
McShane, P. M. "Optimization of the morphological, mechanical and rheological properties of novel polypropylene/ethylene-octene copolymer blends for automotive fuel line protection applications." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268405.
Full textKelly, Adrian L. "On-line shear and extensional rheometry of polymer melts in the extrusion process." Thesis, University of Bradford, 1997. http://hdl.handle.net/10454/2796.
Full textMuñoz, Pablo Andrés Riveros. "Graftização de anidrido maleico em polipropileno, por extrusão reativa, na presença de nanopartículas: estudo de reação e monitoramento in-line." Universidade Federal de São Carlos, 2014. https://repositorio.ufscar.br/handle/ufscar/720.
Full textUniversidade Federal de Sao Carlos
The grafting reaction of maleic anhydride onto polypropylene by reactive extrusion, in presence of nanoclay, was studied. The organoclay (Cloisite 20A) was used as support for dicumyl peroxide (DCP), and different amounts of clay were used. The increment in the clay amount leads to reduction in the reaction rates, because it hinders the peroxide release, once organoclay absorbs partially the peroxide. Changes in the reaction mechanisms, in presence and absence of clay, were performed in a Haake internal mixing chamber, between 1 and 7 min of reaction. The results showed changes in the number, and length of maleic anhydride grafting, and in the molar mass. The reactive extrusion of polypropylene with maleic anhydride was studied based in central composite experimental design, using as factors the maleic anhydride and dicumyl peroxide concentrations. The experimental design was analyzed by ANOVA and shows that the increment in clay, used as peroxide support, leads to decrease in the grafting reaction of short succinic groups, by the introduction of long succinic groups, because its concentration increases the maleic anhydride homopolymerization. In the same way the increase in maleic anhydride concentration leads to decrease in the PP grafting level, because the maleic anhydride homopolimerization is increased, decreasing the reaction between polymer and monomer. The in-line monitoring of the reactive extrusion showed a good correlation between the light absorption measured and the formation of secondary reaction products, lately identified off-line as poli(maleic anhydride).
Neste trabalho estudou-se a reação de graftização de anidrido maleico em polipropileno, por extrusão reativa, na presença de nanopartículas argila montmorilonita. A argila montmorilonita organicamente modificada (Cloisite 20A) foi utilizada como suporte para o peróxido de dicumila (DCP), e foi testada em diferentes proporções. Este estudo mostrou que a argila é capaz de absorver parcialmente o peróxido, e que a quantidade de peróxido absorvida interfere no rendimento das reações. As alterações no mecanismo de reação, induzidas pela presença de argila, foram inicialmente estudadas em câmara de mistura Haake, sendo que a reação, na presença e ausência da argila, foi realizada entre 1 e 7min. Os resultados indicam alterações no tamanho e número de enxertias, além de alterações na degradação das cadeias poliméricas, estudadas através de SEC. Já a extrusão reativa do polipropileno com anidrido maleico, foi estudada com base em um planejamento experimental tipo composto central, onde os fatores estudados foram as concentrações de anidrido maleico e peróxido. A análise do planejamento experimental, realizada por ANOVA, mostra que a presença da argila, utilizada como suporte para o peróxido, tende a diminuir a quantidade de enxertias succínicas curtas, favorecendo a inserção de enxertias succínicas longas, devido à maior incidência das reações de homopolimerização do anidrido maleico. De maneira análoga o aumento nas concentrações de anidrido maleico, diminui o nível de reação, pois há maior concorrência entre as reações de graftização e homopolimerização do monômero. O monitoramento em tempo real das extrusões, mostrou a possibilidade de quantificação da modificação química por meio de colorimetria in-line, através do monitoramento da formação de produtos secundários, identificados como poli(anidrido maleico).
Coben, Collin. "Use of Pyrolyzed Soybean Hulls as Fillers in Polyolefins." University of Akron / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1590601881643166.
Full textMinot, Sylvain. "Contribution de l’analyse de surface à la compréhension des mécanismes d’application d’un traitement de surface innovant en voie sèche des fibres naturelles (technologie du fluor gazeux)." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1119.
Full textThe objective of this thesis was to study a new surface treatment based on contact with a gaseous reaction mixture F2/O2. (oxyfluorination) already used industrially on polymers but not yet applied to natural fibres. This work was part of a collaborative project aimed at studying and developing the industrial applications of this treatment on natural fibres of vegetable (cotton, linen) and animal (wool and silk) origin. The aim was to integrate mainly oxygenated functions. The understanding of the mechanisms involved was achieved by combining several surface analysis techniques, including microscopy techniques (SEM, AFM) and spectroscopic techniques (XPS, ToF-SIMS). Thanks to the complementarity of these different analysis techniques, it appeared that the oxyfluorination treatment does not degrade the surface and introduces a significant quantity of oxygen on the surface, which is not very dependent on the initial composition of the support but with chemical functions that vary according to the initial chemical structure. The results obtained, particularly in stability tests, have shown that fluorine, also detected on the surface after treatment, is not really integrated into the chemical structure of the supports. The comparison with plasma treatments showed that the treatment has less variability, which was confirmed by considering, via a design of experiments, all the possible modifications in an industrial application context. The study of an industrial transfer was then implemented in the case of the replacement of preparation treatments before dyeing cotton and the effectiveness was tested according to the results of the business tests. The lack of treatment variability did not allow to identify sufficiently optimal conditions to propose the replacement of current treatments despite the advantages of gas phase and atmospheric pressure treatment
Engelbrecht, Deborah. "The life cycle assessment of cyanide containers in Ghana." Diss., 2010. http://hdl.handle.net/10500/3603.
Full textEnvironmental Science
M.Sc. (Environmental Science)
Heeley, E. L., Timothy D. Gough, D. J. Hughes, W. Bras, J. Rieger, and A. J. Ryan. "Effect of processing parameters on the morphology development during extrusion of polyethylene tape: An in-line small-angle X-ray scattering (SAXS) study." 2013. http://hdl.handle.net/10454/9663.
Full textThe in-line development of crystalline morphology and orientation during melt extrusion of low density polyethylene (LDPE) tape at nil and low haul-off speeds has been investigated using Small-Angle X-Ray Scattering (SAXS). The processing parameters, namely haul-off speed and distance down the tape-line have been varied and the resulting crystalline morphology is described from detailed analysis of the SAXS data. Increasing haul-off speed increased orientation in the polymer tape and the resulting morphology could be described in terms of regular lamellar stacking perpendicular to the elongation direction. In contrast, under nil haul-off conditions the tape still showed some orientation down the tape-line, but a shish-kebab structure prevails. The final lamellae thickness (similar to 50 angstrom) and bulk crystallinity (similar to 20%), were low at, for all processing conditions investigated, which is attributed to the significant short-chain branching in the polymer acting as point defects limiting lamellae crystal growth. (C) 2013 Elsevier Ltd. All rights reserved.
BAILLY, Mathieu Roger Marcel. "Preparation and characterization of polyolefin / nanosilica composites." Thesis, 2011. http://hdl.handle.net/1974/6374.
Full textThesis (Ph.D, Chemical Engineering) -- Queen's University, 2011-04-18 15:17:52.471
Coates, Philip D., Philip D. Caton-Rose, Ian M. Ward, and Glen P. Thompson. "Process structuring of polymers by solid phase orientation processing." 2013. http://hdl.handle.net/10454/9638.
Full textSolid phase orientation of polymers is one of the most successful routes to enhancement of polymer properties. It unlocks the potential of molecular orientation for the achievement of a range of enhanced physical properties. We provide here an overview of techniques developed in our laboratories for structuring polymers by solid phase orientation processing routes, with a particular focus on die drawing, which have allowed control of significant enhancements of a single property or combinations of properties, including Young's modulus, strength, and density. These have led to notable commercial exploitations, and examples of load bearing low density materials and shape memory materials are discussed.