Dissertations / Theses: 'Plastics'

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Al-Ati, Tareq. "Oxygen permeation of virgin HDPE films versus recycled HDPE films /." Online version of thesis, 1994. http://hdl.handle.net/1850/11875.

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LINDSTRAND, NILS, and KARL THUNELL. "From Plastic to Paper Mapping the real cost of plastics." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-224931.

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Doshi, Shailesh R. "A novel coextrusion process for the manufacture of short fiber-reinforced thermoplastic pipe /." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72817.

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Pitteri, Silvio. "Processing and evaluation of filled thermoplastics." Thesis, Brunel University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253309.

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Lovett, Michael Scott. "The ultrapyrolytic upgrading of waste plastics and plastics/heavy oil mixtures." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq20877.pdf.

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Dura, Matthew Jonathon. "Behavior of Hybrid Wood Plastic Composite-Fiber Reinforced Polymer Structural Members for Use in Sustained Loading Applications." Fogler Library, University of Maine, 2005. http://www.library.umaine.edu/theses/pdf/DuraMJ2005.pdf.

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Bodalia, Raj. "An investigation of the "walking" behavior in the manufacturing of biaxially oriented polypropylene films /." Online version of thesis, 1988. http://hdl.handle.net/1850/10691.

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Aw, Cheong Soon (Samuel). "A study to evaluate the permeation characteristics of black tea flavors and linalool in four different plastic films /." Online version of thesis, 1995. http://hdl.handle.net/1850/11853.

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Jaffer, Shaffiq A. "Experimental studies of static mixers and twin screw extruders /." *McMaster only, 1998.

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Fisher, Tom. "Plastics in contemporary consumption." Thesis, University of York, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.542812.

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Benson, Margaret. "Disposal of thermosetting plastics." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310518.

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Resen, Abdul-Amir S. "Biaxial creep of plastics." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.256753.

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13

Bonas, Calvin (Calvin A. ). "Re-usability of plastics." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32877.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.
Includes bibliographical references (p. 42-43).
A research project was designed in order to learn more about the quality of recycled plastics when compared to new material. The study was carried out by researching and learning about how the recycling process operates. Further research was then conducted on the seven different types of resins that exist in the recycling world today. After collecting the data, an experiment was devised in order to learn more about the capabilities of using recycled plastics for regular household applications. The results of the experiment showed that most of the seven recyclable plastics could actually be used again as along as special care was taken to ensure that the quality of the recycled product was equivalent to that of the virgin material. However, it was determined that a more rigorous recycling program for plastic would be feasible but it is not a practical endeavor for economic purposes. As a result, many of the manufacturers within the plastics realm prefer to use new plastic as opposed to recycling their products.
by Calvin Bonas.
S.B.

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14

Thomson, Hilary Elizabeth. "Ignition characteristics of plastics." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/13123.

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Rabinovich, Daniel. "Just one word: Plastics." Revista de Química, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/100995.

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McDonald, Seonaidh. "The management of post-consumer plastics waste recycling in the UK." Thesis, University of Stirling, 1996. http://hdl.handle.net/1893/1786.

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This thesis examines the management of post-consumer plastics waste recycling in the UK. It brings together information and approaches from a number of disciplines in order to present a comprehensive view of the post-consumer plastics waste recycling industry and provide insight into participation issues. Two Scottish collection schemes are utilised as case studies throughout. The thesis summarises current practice in post-consumer plastics recycling and describes the processes associated with it. It also presents a summary of legislation relevant to plastics recycling in the UK, EC and US in particular. The thesis includes a quantitative survey of 500 members of the public that analyses their recycling behaviour and factors that affect motivation. It also looks at public perceptions of plastics. This is complemented by a qualitative study of plastics recyclers that examines recycling routines in more detail, and explores issues that affect the participation, and quality of donation, of individuals. The evaluation of post-consumer plastics recycling schemes is discussed, and models are developed in order to assessth eir financial viability. The lessons gained from this programme of research are then summarised in a policy framework.

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Ferguson, Sean Michael. "Plastics Without Petroleum History and Politics of 'Green' Plastics in the United States." Thesis, Rensselaer Polytechnic Institute, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3557924.

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Among the new technologies heralded as part of the emerging bioeconomy are plastics made from plant material, known as bioplastics. This dissertation examines the political and historical underpinnings of the bioplastics that are now being offered as an alternative to petrochemicals in the United States. As a case study of "green" technological development, bioplastics challenge dominant conceptions of innovation for sustainability. The bioplastics being developed and marketed today are the outcome of interventions in commodity crop prices, incubation of research on biomass during periods of fossil fuel dominance, and the commercialization of publicly funded research. Their origins can be traced at least as far back as the 1920s, when advocates of "chemurgy" encouraged the federal government to create research centers to discover new industrial uses of agricultural crops.

Research in science and technology studies (STS) indicates that social structures shape perceptions of problems, condition viable solutions, and limit the diversity of stakeholders and ideas present in the social construction of technology. This study examines these processes in the history and current debates about bioplastics. The dissertation asks who has influenced the social construction of bioplastics and why bioplastics have become part of a larger bioeconomic vision now. Theoretical insights are drawn from the sociological theory of the treadmill of production, which argues that environmental problems cannot be solved in a capitalist system in which the federal government, private industries, and organized labor continuously seek the expansion of production and consumption at the expense of environmental sustainability. Major players in the chemical and biotechnology industries have pursued bioplastics as a means of continuing economic growth and consumption of goods, even as petroleum becomes costly and environmentalists voice objections to petrochemicals. There are many critiques of bioplastics and their impacts at every stage of bioplastics, from sourcing feedstocks from food crops to disrupting existing recycling and composting systems. Nevertheless, the bioplastics currently on the market were not designed to resolve these environmental concerns. Increasingly, however, activists are using non-governmental institutions, particularly the development of voluntary standards, to shape the industry and technology. The study examines the extent to which such reforms might lead to the production of more sustainable alternatives to petrochemicals.

Ultimately, this dissertation presents the history and politics surrounding the field of bioplastics in order to highlight how things "might have been otherwise" and what changes in society could be useful for producing more sustainable technologies.

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Sævik, Svein. "On stresses and fatigue in flexible pipes." Norway : Dept. of Marine Structures, the University of Trondheim, 1992. http://catalog.hathitrust.org/api/volumes/oclc/27348152.html.

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Buys, Alexander George. "Performance evaluation of aluminium alloy 7075 for use in tool design for the plastic industry." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/1246.

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Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2009.
The objective of this project was to measure the performance of high-strength aluminium alloys as injection mould material compared against conventionally used tool steel.

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Kasichainula, Nagesh. "Mechanic characterization of reinforced rigid polyurethane foams /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p1418038.

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Halliwell, Susan M. "Weathering of plastics glazing materials." Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/15369.

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Plastics glazing materials have properties which allow their widespread use in construction, for example as rootlights. However, they are more susceptible than is glass to degradation by weathering, notably the combined effects of ultraviolet light, heat and moisture. Examples of unacceptable durability have been seen in practice, particularly when high operating temperatures occur in sunlight. Artificial weathering tests are used to assess plastics glazing materials in a reasonably short time, two main types being utilised in this study. The applicability of ultra-fast methods of accelerated degradation has been shown to depend on the extent to which the mechanisms of degradation simulate practical weathering, since different procedures were found to promote different mechanisms in the materials tested. Misleading information was obtained when the full spectrum of solar UV and much of the visible was not adequately reproduced in the accelerated tests. In particular an established grade of PVC-U performed unexpectedly poorly under fluorescent lamps. Procedures based on xenon arc sources were found to be the most generally applicable because they better reproduce the full solar spectrum range and, hence, the typical effects observed in plastics materials in practice. Several analytical techniques were used to characterise the virgin polymers and to assess the weathered materials. Two commercial grades of each polymer type (poly[vinylchloride], polycarbonate and poly[methylmethacrylate]) were studied, and measured changes explained in terms of initial polymer properties. Profiling of chemical (e.g. carbonyl index measured by photo-acoustic fourier transform infrared), physical (e.g. molecular weight, surface gloss/roughness), optical (e.g. colour, light transmission) and mechanical properties (e.g. impact resistance) as a function of exposure period and environmental conditions enabled degradation rates and mechanisms to be established for each material. In conducting these tests particular attention was given to the control and effects of sample temperature during weathering, and to the wavelength range of the light source used. Poly(vinylchloride) was affected much more by weathering at higher temperatures, and by exposure to short wavelength radiation, than was polycarbonate, with acrylic being the most durable overall. Practical applications of this work are through Standards committees primarily. in particular with plastics rootlights (B/542/8 and CEN/TCI28/SC9).

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Harkin-Jones, Eileen M. A. "Rotational moulding of reactive plastics." Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317442.

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Freitas, Pedro Guilherme de Valle-Flôr Telles de. "Auditoria a Key Plastics Portugal." Master's thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/9338.

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Dissertação para a obtenção do grau de Mestre em Engenharia Mecânica
O presente trabalho consiste numa auditoria energética a uma unidade fabril de injecção de plástico para a indústria automóvel. Inicialmente foi efectuado um trabalho de recolha e levantamento de dados dos consumos energéticos que existiam na Key Plastics Portugal. Foram identificados os principais consumidores de energia e estudadas possíveis soluções de melhoria com vista à redução do consumo energético dos mesmos. Este estudo envolveu a execução de planos de retorno simples com vista a determinar, para o montante orçamentado, qual era a viabilidade do estudo face a conjectura económica que vivemos.

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24

Wang, Bo. "Integrated analyses in plastics forming." Thesis, Sheffield Hallam University, 1996. http://shura.shu.ac.uk/19363/.

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This is the thesis which explains the progress made in the analysis, simulation and testing of plastics forming. This progress can be applied to injection and compression mould design. Three activities of plastics forming have been investigated, namely filling analysis, cooling analysis and ejecting analysis. The filling section of plastics forming has been analysed and calculated by using MOLDFLOW and FILLCALC V. software. A comparing of high speed compression moulding and injection moulding has been made. The cooling section of plastics forming has been analysed by using MOLDFLOW software and a finite difference computer program. The latter program can be used as a sample program to calculate the feasibility of cooling different materials to required target temperatures under controlled cooling conditions. The application of thermal imaging has been also introduced to determine the actual process temperatures. Thermal imaging can be used as a powerful tool to analyse mould surface temperatures and to verify the mathematical model. A buckling problem for ejecting section has been modelled and calculated by PATRAN/ABAQUS finite element analysis software and tested. These calculations and analysis are applied to the special case but can be use as an example for general analysis and calculation in the ejection section of plastics forming.

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25

Owsiany, Dana Lynn 1969. "Sand stabilization using waste plastics." Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/291370.

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A study on the possible use of melted waste thermoplastics to stabilize soils, and produce plastic-soil structural composites is presented. Specifically, the effects of melted thermoplastics on the shear strength, and creep characteristics of sands are examined. An extensive experimental program was conducted to examine the strength and creep characteristics of different plastic-sand compositions. It was found that increasing plastic content in the sand results in stronger, and stiffer soils with negligible creep deformations for loads which are at least 50% of the strength of the composite. It is expected that injection of melted waste thermoplastics in sands can improve significantly the engineering characteristics of foundation, and slope stability of sands. Other potential applications include construction of structural elements, bricks, etc.

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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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Pickens, Mark Everett Vaidyanathan Vijay Varadarajan. "Design and validation of an automated multiunit composting system." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/ark:/67531/metadc12184.

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Strand, Seth R. "Effects of Friction Stir Welding on Polymer Microstructure." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd338.pdf.

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Bravo, Victor. "Finite element simulation of flow in twin screw extruder mixing elements." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0005/NQ42727.pdf.

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30

Lee, One-Chul. "Creep phenomenon of fiber reinforced plastics." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/21003.

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Vainstein, Jimmy. "A study of the conditions and variables that affect the printing of shrink films on waterbased flexography /." Link to online version, 2005. https://ritdml.rit.edu/dspace/handle/1850/1107.

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32

Souza, Benjamin J. "Fracture Mechanics Characterization of WPC-FRP Composite Materials Fabricated by the Composites Pressure Resin Infusion System (Compris) Process Volume I (Chapters 1-7, Appendix A)." Fogler Library, University of Maine, 2005. http://www.library.umaine.edu/theses/pdf/SouzaBJ2005.pdf.

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33

Kaartinen, Johanna. "A Checklist for Plastic Product Design: Preventing Pitfalls in a Design Process and Premature Failures of Plastic Products." Thesis, Högskolan i Skövde, Institutionen för ingenjörsvetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-9683.

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Designing an injection molded plastic part requires optimizing the part with respect to various stakeholders’ needs throughout its life cycle. The conditions in which a product is operating in service are often inadequately understood or specified, resulting in wrong material selection, which in turn leads to failure when the product is used. Many aspects interrelate with the initial part design and the essential rules of each should be taken into account to ensure a well-functioning plastic product. Regardless, a part design often passes sequentially from concept development to the manufacturing phase with features that unnecessarily complicate production, add costs and weaken the intended embodiment of the product. Therefore, a checklist was developed to ensure that oversights do not happen and verify that a design fulfills the requirements set for it. The commissioning company in the project was the design office Sytyte Oy. The aim of this thesis work was to investigate the effects of design decisions on the product’s feasibility and performance in service. The study focused on the underlying reasons for failures in plastic products, failure phenomena and ways of preventing them. The project started with literature research. To support the theoretical review, a small-scale survey was conducted among operators in plastic industry in Finland to strengthen the outcome of the project. The findings from the research were compiled into a checklist. The approach into the list was adopted from the FMEA method aiming to create a stripped-down version of it. The result offers a tool for anticipating and spotting possible failures by bringing up the influences that most frequently affect the part performance. It contributes to preventing delays in processing and premature failures in service. The checklist was verified by specialist consultation to receive suggestions and requirements for improvements and to ensure its reliability.

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Moran, Matthew T. "Testing the predictability of water-based flexographic inks on plastic substrates /." Online version of thesis, 1993. http://hdl.handle.net/1850/11271.

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Ruan, Haihui. "Collision between two perfectly plastic beam structures : modeling and verification /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?MECH%202004%20RUAN.

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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2004.
Includes bibliographical references (leaves 235-241). Also available in electronic version. Access restricted to campus users.

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36

George, Andrew R. "A new spectroscopic method for the non-destructive characterization of weathering damage in plastics /." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1605.pdf.

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37

Statler, David. "A mechanistic and modeling study of recycled and virgin flame retarded polycarbonate." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5656.

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Thesis (Ph. D.)--West Virginia University, 2008.
Title from document title page. Document formatted into pages; contains xvii, 180 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 166-173).

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Velpuri, Seshagirirao V. "Fracture Toughness Testing of Plastics under Various Environmental Conditions." Thesis, University of North Texas, 1997. https://digital.library.unt.edu/ark:/67531/metadc278346/.

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The primary objective of this study is to test the applicability to plastics of a fracture toughness testing tool developed for metals. The intent is to study pre-test conditioning of several plastic materials and the effect of the depth of the razor notch cut in the chevron notched fracture toughness test specimens. The study includes the careful preparation of samples followed by conditioning in various environments. Samples were subjected to laboratory air for a specific duration or to a controlled temperature-humidity condition as per the ASTM D1870. Some of the samples were subjected to vacuum conditioning under standard test specifications. Testing was conducted using the conventional three-point bend test as per ASTM D5045-95. ASTM E1304, which sets a standard for short rod and bar testing of metals and ceramics provides some basis for conducting chevron notched four-point bend tests to duplicate the toughness tool. Correlation of these results with the ASTM test samples is determined. The four-point bend test involves less specimen machining as well as time to perform the fracture toughness tests. This study of fracture toughness testing has potential for quality control as well as the fracture property determination.

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39

Kwok, Siu-man. "Predicting the creep behaviour of plastics /." [Hong Kong] : University of Hong Kong, 1990. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12996312.

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Zakharova, Elena. "Sustainable plastics derived from renewable resources." Doctoral thesis, Universitat Politècnica de Catalunya, 2017. http://hdl.handle.net/10803/461889.

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In this century, the major use of synthetic polymers have been as replacements for more traditional materials, particulary in packaging. Today the packaging industry is by far the major user of plastics. Another interesting application of these materials is drug delivery systems. Polymers have played an integral role in the advancement of drug delivery technology by providing controlled release of therapeutic agents in constant doses over long periods, cyclic dosage and tunable release of both hydrophilic and hydrophobic drugs. Modern advances in drug delivery are now predicated upon the rational design of polymers tailored for specific cargo and engineered to exert distinct biological functions. Aliphatic polyesters such as poly(L-lactic acid), poly(butylene succinate), and polyhydroxyalkanoates among others, constitute primary examples of bio-based polymers that distinguish by being fully renewable and displaying partial or total biodegradability. This Ph.D. Thesis is devoted to the synthesis of aliphatic random and block polyesters from renewable resources with application for packaging and drug delivery. The main goal of this project is to develop new bio-based polymers with similar or even improved properties compared to those of conventional plastics obtained from non-renewable sources. The two cyclic acetals, 2,3-di-O-methylene-L-threitol and dimethyl 2,3-di-O-methylene-L-threarate, were used for the synthesis of two series of PBS copolyesters differing in which unit, butylene or succinate, was replaced, in addition of the corresponding parent homopolyesters. 2,4:3,5-di-O-methylene-D-glucitol was used for the synthesis of PBS copolyesters by melt polycondensation. Three series of polyalkanoates (adipates, suberates and sebacates) were synthesized using as monomers three sugar-based bicyclic diols derived from D-glucose and D-mannose. ABA triblock copolyesters were synthesized by ROP of L-lactide in solution initiated by telechelic D-glucose- and L-tartaric-based polyester macroinitiators. The synthesized polyesters were characterized by nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC) and viscosimetry. Thermal properties were analyzed by differential scanning calorimetry (DCS) and thermogravimetry (TGA). Crystalline structure of polyesters was studied by X-ray and its mechanical properties were evaluated as well. Hydrolytic degradation and biodegradation assays were followed by GPC and NMR. Nanoparticles made from triblock copolyesters were characterized by scanning electron microscopy (SEM) and dynamic light-scattering (DLS).
En este siglo, el mayor empleo que se les ha dado a los polímeros sintéticos ha sido como sustitutos de materiales más tradicionales, en particular, materiales para envase y embalaje. Hoy en día la industria de envasado es, por mucho, la mayor consumidora de plásticos. Otra aplicación interesante de estos materiales son los sistemas de administración de fármacos. Los polímeros han jugado un papel fundamental la tecnología de administración de fármacos al proporcionar un medio de liberación controlada de agentes terapéuticos en dosis constantes durante largos periodos; la dosificación cíclica y la liberación sintonizable de fármacos hidrofílicos e hidrofóbicos. Actualmente, los avances modernos en la administración de fármacos se basan en el diseño racional de polímeros para la liberación de dosis controladas que modifican distintas funciones biológicas de forma específica. Los poliésteres alifáticos tales como el poli(ácido L-láctico), el poli(succinato de butileno) y los polihidroxialcanoatos, entre otros, constituyen ejemplos primarios de polímeros de base biológica que se distinguen por ser completamente renovables y presentar biodegradabilidad parcial o total. Este trabajo de doctorado está dedicado a la síntesis de poliésteres alifáticos al azar y de bloques a partir de recursos renovables con aplicación para el envasado y la administración de fármacos. El objetivo principal de este proyecto es desarrollar nuevos polímeros biológicos con propiedades similares o incluso mejores en comparación a los plásticos convencionales obtenidos a partir de fuentes norenovables. Los dos acetales cíclicos, 2,3-di-O-metileno-L-treitol y dimetil 2,3-di-O-metileno-L-trearato, se usaron para la síntesis de dos series de copoliésteres de PBS que difieren en qué unidad, butileno o succinato, se reemplazó, además de los homopoliésteres originales correspondientes. Se usó 2,4:3,5-di-O-metileno-D-glucitol para la síntesis de copoliésteres de PBS mediante policondensación en estado fundido. Se sintetizaron tres series de polialcanoatos (adipatos, suberatos y sebacatos) usando como monómeros tres dioles bicíclicos base azúcar derivados de D-glucosa y D-manosa. Los copoliésteres tribloques ABA se sintetizaron mediante ROP de L-láctido en solución iniciada por macroiniciadores de poliester telequelico basados en D-glucosa y L-tartárico. Los poliésteres sintetizados se caracterizaron por espectroscopia de resonancia magnética nuclear (RMN), cromatografía de permeación en gel (GPC) y viscosimetría. Las propiedades térmicas se analizaron mediante calorimetría de barrido diferencial (DCS) y termogravimetría (TGA). La estructura cristalina de los poliésteres se estudió mediante rayos X y sus propiedades mecánicas también se evaluaron. La degradación hidrolítica y los ensayos de biodegradación fueron seguidos por GPC y NMR. Las nanopartículas hechas de copoliésteres tribloque se caracterizaron por microscopía electrónica de barrido (SEM) y dispersión de luz dinámica (DLS).

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Gao, Feng. "Pyrolysis of Waste Plastics into Fuels." Thesis, University of Canterbury. Chemical and Process Engineering, 2010. http://hdl.handle.net/10092/4303.

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Waste plastic disposal and excessive use of fossil fuels have caused environment concerns in the world. Both plastics and petroleum derived fuels are hydrocarbons that contain the elements of carbon and hydrogen. The difference between them is that plastic molecules have longer carbon chains than those in LPG, petrol, and diesel fuels. Therefore, it is possible to convert waste plastic into fuels. The main objectives of this study were to understand and optimize the processes of plastic pyrolysis for maximizing the diesel range products, and to design a continuous pyrolysis apparatus as a semi-scale commercial plant. Pyrolysis of polyethylene (PE), polypropylene (PP), and polystyrene (PS) has been investigated both theoretically and experimentally in a lab-scale pyrolysis reactor. The key factors have been investigated and identified. The cracking temperature for PE and PP in the pyrolysis is at 450 ºC, but that of PS is lower, at 320 ºC. High reaction temperature and heating rate can significantly promote the production of light hydrocarbons. Long residence time also favours the yield of the light hydrocarbon products. The effects of other factors like type of reactor, catalyst, pressure and reflux rate have also been investigated in the literature review. From the literature review, the pyrolysis reaction consists of three progressive steps: initiation, propagation, and termination. Initiation reaction cracks the large polymer molecules into free radicals. The free radicals and the molecular species can be further cracked into smaller radicals and molecules during the propagation reactions. β-scission is the dominant reaction in the PE propagation reactions. At last, the radicals will combine together into stable molecules, which are termination reactions. There are three types of cracking of the polymers: random cracking, chain strip cracking, and end chain cracking. The major cracking on the polymer molecular backbone is random cracking. Some cracking occurs at the ends of the molecules or the free radicals, which is end chain cracking. Some polymers have reactive functional side group on their molecular backbones. The functional groups will break off the backbone, which is chain strip cracking. Chain strip cracking is the dominant cracking reaction during polystyrene pyrolysis. The reaction kinetics was investigated in this study. The activation energy and the energy requirement for the pyrolysis are dependent on the reaction process and the distribution of the final products. Following the equations from other literatures, the theoretical energy requirement for pyrolyze 1kg PE is 1.047 MJ. The estimated calorific value of the products is about 43.3 MJ/kg. Therefore, the energy profit is very high for this process. The PE pyrolysis products are mainly 1-alkenes, n-alkanes, and α, ω-dialkenes ranging from C1 to C45+. The 1-alkenes and the n-alkanes were identified with a special method developed in this research. It was found that secondary cracking process has a significant influence on the distribution of the product. This process converts heavy hydrocarbons into gas or light liquid product and significantly reduces 1-alkenes and α, ω-dialkenes. This secondary process can be controlled by adjusting the reflux rate of the primary product. The product of PE pyrolysis with maximized diesel range output consist of 18.3% non-condensable gases, 81.7% w/w liquid product, and less than 1% pure carbon under high reflux rate process. Some zeolite catalysts were tested to reduce the heavy molecular weight wax. It was found that NKC-5 (ZSM-5) was the most effective catalyst among zeolites tested. The proportion of the non-condensable gases was promoted from 17% w/w to 58% w/w by adding 10% w/w NKC-5 into the PE feedstock. The products of PP pyrolysis are mainly methyl- oligomers. The reflux effect on the product from pyrolysis of PP is not as great as that on PE. The PP pyrolysis product with high reflux rate consists of 15.7% non-condensable gases, 84.2% condensed liquid product, and less than 0.25% char. Cyclohexane is the dominant component, 21%w/w in the liquid product. 44%v/v of the non-condensable gases is propene. In the pyrolysis product of PS, there are 4% non-condensable gases, 93% liquid, and 3% char. Styrene accounts for 68.59%w/w in the PS liquid pyrolysis products due to the chain strip reactions. There was 19% v/v hydrogen in the gas product, which did not exist in the PE pyrolysis gas product. The composition of the char is almost pure carbon, which is similar to that from PE pyrolysis. The mixture of virgin and post-consumer PE, PP and PS have also been investigated to identify the feedstock interaction and the effect of the contamination on the product. The interaction promotes the production of non-condensable gases. However, the effect of the interaction on the distribution of total product is not significant. Contamination of paper labels on the post-consumer plastics may result in higher solid residue in the product but no significant effect on the product was found in this study. Based on the achievements, a continuous semi-scale reactor has been designed and constructed at maximum capacity of 27.11kg/hr in this research. From the experiments of pyrolysis of both virgin PE and post-consumer PE on this semi-scale pyrolysis reactor, it was found that the major components are 1-alkenes, n-alkanes, and α, ω- dialkenes. The distribution of the condensed products of PE pyrolysis from the semiscale reactor is the same as that of the products from low reflux rate process with the lab-scale reactor. However, the proportion of non-condensable gases is much higher than that from pyrolysis in the lab-scale tests with low reflux rate because the semiscale plant has higher reaction temperature and heating rate. Lower proportion of unsaturated hydrocarbons was found in the condensed product from the post-consumer PE pyrolysis than in the virgin PE product because of the contamination on the postconsumer PE. The actual energy consumption for cracking and vaporizing PE into fuels is 1.328 MJ/kg which is less than 3% of the calorific value of the pyrolysis products. Therefore, the pyrolysis technology has very high energy profit, 42.3 MJ/kg PE, and is environmental-friendly. The oil produced has very high quality and close to the commercial petroleum derived liquid fuels. The experience of design and operation of the semi-scale plant will be helpful for building a commercial scale plant in the future.

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42

郭紹文 and Siu-man Kwok. "Predicting the creep behaviour of plastics." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1990. http://hub.hku.hk/bib/B31209762.

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Lam, Ho-ching Dennis, and 林浩正. "Biodegradable plastics : feasible in Hong Kong?" Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/194554.

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Since their inception and invention, plastic materials have taken on an essential role in numerous applications within the lives of human beings for years now. Each year, the global figure for production of plastic is estimated to be more than 100 million tons. The major reason for the existence of such an enormous amount is due to plastics’ supremacy over other materials with their exceptionally useful properties. According to Hong Kong’s Environmental Protection Department, 13,458 tons of waste was disposed in Hong Kong’s landfills per day during 2011. Such an amount is very large in quantity, and it is predicted that the three strategic landfills of Hong Kong will be fully saturated in 2015-16 if the waste generation rate remains similar as present time and business as usual. Plastics made up approximately 19% of the overall composition of Hong Kong’s disposed municipal solid waste in 2011. Plastic material does not degrade efficiently, and since it has only been in production during the most current century, plastic specialists have not been able to conclude the final life span of the material before it completely degrades. Estimates for different plastic polymers range from 20 years to 400 years and above. To solve these increasingly serious environmental issues, the society has raised its demands and directed many researches into biodegradable polymers (i.e., plastics). They have now become more seriously considered as alternative solutions for conventional, non-biodegradable plastics. However, the creation of such biodegradable materials, the efficiency and cost of that creation and the true biodegradability of those materials is under much scrutiny and debate. The purpose of this study was multi-faceted. It primarily focused on (1) the status and production of biodegradable products in Hong Kong and (2) assessment of the general public’s receptiveness towards using such products. This study aimed to evaluate the above two aspects via literature review and interviews of representatives from biodegradable plastics companies in Hong Kong as well as students and general working-class citizens. This element inquired whether the general public would be willing to pay extra money to use biodegradable plastic products, and whether they thought that these products had beneficial effects towards environmental conservation and protection. Also, the general public would be asked their opinion on a duty for biodegradable products and whether they would be adverse to a policy implementation involving such a duty. A large portion of this project’s critically significant data was generated from random, systematic sampling of different people, asking them about the aforementioned monetary scenarios. Results were insightful and informative giving evident trends that represented the public’s attitude towards biodegradable plastics. Overall, the public was positively supportive of biodegradable technology, which is relatively new. Concurrently, extensive literature review was conducted to assess foreign practices and policies regarding biodegradable plastics, as well as the life-cycle of a primary biopolymer called polylactic acid. A concluding recommendation was constructed to envision the future waste management infrastructure in Hong Kong. That infrastructure could build off of the special region’s budding development of incinerators, composting facilities, waste-to-energy facilities, and sorting technologies. Then, to supplement biodegradable polymer production and post-use handling facilities, the Hong Kong SAR Government could implement strong waste management policies to motivate its society to aim for a more sustainable way of life.
published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management

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44

Chow, Ping-Sheng. "Separation of mixed plastics by flotation." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318720.

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Ayre, David Stephen. "Dilatational yielding in rubber-toughened plastics." Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300983.

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Berkery, Daniel J. (Daniel John). "Process monitoring for plastics injection molding." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12746.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1993 and Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1993.
Includes bibliographical references (leaves 196-197).
by Daniel John Berkery.
M.S.

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47

Brennan, Louise B. "Recycling plastics from waste computer equipment." Thesis, Swansea University, 2004. https://cronfa.swan.ac.uk/Record/cronfa43077.

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In light of recent European legislation, an increase in recycling and recovery activities is required in the electrical and electronic sector in order to meet stipulated targets. For waste plastics this also includes the separation of plastics containing brominated flame retardants from those that do not. Studies into the FTIR (Fourier transform infrared) spectra of a collection of plastics from waste housings for computer equipment and comparisons with spectra from a selection of flame retardants, as well as testing different plastics identification systems have concluded that infrared spectroscopy cannot be used to detect flame retardants in plastics in the current state of technology. However flame retardants may be detected by using a combination of identification techniques such as IR (infrared) for plastic identification and pyrolytic spectroscopy for additive detection. The effects of recycling and blending on a commercial scale have been assessed on mechanical properties of the four most used plastics in computer equipment housings. Recycled ABS (acrylonitrile-butadiene-styrene), HIPS (high impact polystyrene), modified PPO (polyphenylene oxide) and PC (polycarbonate) /ABS alloy were tested in the pure form and as various blends of ABS and HIPS, HIPS and modified PPO (mPPO), ABS with PC/ABS and a blend of all four plastics. Properties tested were tensile and impact properties, DMT A (dynamic mechanical thermal analysis), viscosity, molecular weight and surface and bulk microscopy. Generally changes to mechanical properties following recycling of pure ABS, HIPS, PPO and PC/ABS are quite small, although there are slight reductions in ductility for HIPS and mPPO. All plastics used in this study appear unaffected by the presence of a small proportion of another plastic, although at higher blend proportions impact strengths of ABS/PC/ABS deteriorate, properties of ABS/HIPS blends remain unaffected and larger proportions of HIPS/PPO are beneficial to all properties. These results indicate that a plastics identification system probably does not need to be exactly 100% accurate.

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Isay, Alina, Vita Martynenko, Valeriya Kim, Nataliya Lepuha, and Victoria Vostrikova. "Biodegradable polymers for production of plastics." Thesis, Молодь у глобалізованому світі: академічні аспекти англомовних фахових досліджень (англ. мовою) / Укл., ред. А.І.Раду: збірник мат. конф. - Львів: ПП "Марусич", 2011. - 147 с, 2011. http://er.nau.edu.ua/handle/NAU/20867.

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Chohan, Sukhvinder K. "Environmental degradation of polyethylene-based plastics." Thesis, Aston University, 1996. http://publications.aston.ac.uk/9675/.

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The criteria involved in the degradation of polyethylene-based degradable polymer samples have been investigated, with a view to obtaining a clearer mechanism of photo-biodegradation. The compatibility of degradable polymer samples during materials recycling was also studied. Commercial and laboratory prepared degradable polymer samples were oxidised in different environments and the oxidation products formed were studied using various analytical chromatographic and spectroscopic techniques such as HPLC, FT-IR and NMR. It was found that commercial degradable polymer samples which are based on the ECO systems, degrade predominantly via the Norrish II process, whereas the other degradable systems studied (starch-filled polyethylene systems, transition metal systems, including metal carboxylate based polyethylene systems and the photoantioxidant-activator systems) photodegrade essentially via the Norrish I process. In all cases, the major photoxidation products extracted from the degradable polymer samples were found to be carboxylic acids, although, in the polymer itself a mixture of carbonyl containing products such as esters, lactones, ketones and aldehydes was observed. The study also found that the formation of these hydrophilic carbonyl products causes surface swelling of the polymer, thus making bioerosion possible. It was thus concluded that environmental degradation of LDPE is a two step process, the initiation stage being oxidation of the polymer which gives rise to bioassimilable products, which are consequently bioeroded in the second stage, (the biodegradation step). Recycling of the degradable polymer samples as 10% homogeneous and heterogeneous blends was carried out using a single screw extruder (180°C and 210°C) and an internal mixer (190°C). The study showed that commercial degradable polymer samples may be recycled with a minimal loss in their properties.

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Busillo, Eric. "Characterization of plastic hypodermic needles." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26584.

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Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Colton, Jonathan; Committee Member: Ku, David; Committee Member: Prausnitz, Mark. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Dissertations / Theses on the topic 'Plastics'

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