by N Li · 2009 · Cited by 8 — This project aimed to examine the quantities of plastic wastes epa/osw/nonhaz/municipal/pubs/msw07-rpt.pdf (accessed.

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Reduce, Reuse, and Replace: A Study o n Solutions to Plastic Wastes An Interactive Qualifying Project Submitted to the faculty of Worcester Polytechnic Institute May 5, 2009 By Ningwei Li Dilasha Mahat Seonhee Park Project Advisor: Professor Robert W. Thompson

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2 Abstract This project aimed to examine the quantities of plastic wastes discarded and the fate of various plastics in the environment. Our Interactive Qualifying Project was concerned with researching the possible alternatives to plastics, m ainly biodegradable plastics that have been claimed to biodegrade and help environment. Moreover, it was also required to evaluate the best methods to deal with our plastic wastes that are environmentally, economically, and energy – wise viable.

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3 Acknowled gement We would like to thank a number of people who greatly helped us and shared their knowledge and experience s to complete this project. First we would like to thank faculty members, wh o were generous enough to take time to answer our questions; Profe ssor Zhou, Mr. Hutson, Professor Brisson, Professor Fehribach, Professor Padir, Mr. Thomsen, Professor Dollenmayer, Professor Masamune, Miss Kumar, and Professor Pietroforte. We would also like to thank Mr. Kraskousakas, director of the Chartwells Services , and Ms. Tomaszeski, the coordinator of the Sustainability and the manager of the Facilities systems, for providing us information on recycling programs and plastic uses in WPI. Finally, we would like to express our sincere gratitude to our advisor, Prof ess or Robert W. Thompson, for guiding and providing feedbacks to us throughout the project.

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4 Acronyms ABS: Acrylonitrile – B utadiene – S tyrene BBzP: B utyl B enzyl P hthalate BLL: Blood Lead Level BPA: Bisphenol A BPI: International Biodegradable Products Insti tute of the United States BPS: Biodegradable Plastics society of Japan DEHA: Bis(2 – ethylhexyl) A dipate DEHP: Bis(2 – ethylhexyl) Phthalate EPA: U.S. Environmental Protection Agency HDPE: High Density Polyethylene HIPS: H igh – I mpact P olystyrene LDPE: Low Densi ty Polyethylene LLDPE: Linear Low Density Polyethylene MSW: Municipal Solid Waste PAYT: ay – A s – Y ou – T PET: Polyethylene Terephthalate PHA: Polyhydroxyalkanoate PHB: Polyhydroxybutyrate PLA: Polylactic Acid PLGA: Poly ( lactic – co – glycolic acid) PP: Poly propylene PS: Polystyrene PUF: P olyurethane F oams

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6 Glossary Dow ncycling: process where the recycled/reproduce product has inferior quality than the original product MSW: more commonly known as tr ash or garbage, consists of everyday items such as product packaging, grass clippings, furniture, bottles, food scraps, newspapers, applian ces, paint, and batteries (EPA) . Recyclates: r ecycled material s that wi ll be used to form new products (AggRegain 2009) Shredder residue: remaining particles after the sorting processed by the trammel in the recycling industry Trommels: screening device s used in the recycling industry for sorting particles of different sizes

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9 Table of Figures Figure 1 MSW Generation Rates from 1960 to 2006 23 Figure 2 Total MSW Generations 24 Figure 3 How the Bottles Bill Works 32 Figure 4 The States with Bottles Bills 32 Figure 5 Bulk Separation and Size Reduction Process 35 Figure 6 Froth Flotation Process 36

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10 Background Plastics Definition of Plastics Plastic is a kind of material that is commonly known and used in everyday life . To define plastic at molecular level, plastic is a kind of organic polymer, which has molecules containing long carbon chains as their backbones with repeating units. The structure of these repeating units and types of atoms play the main role in determining the characteristic s of the plastic. These long carbon chains are well packed together by entanglements and Van der Waals forces between large molecules, and form a strong, usually ducti le solid material. Also, additives are usually added when manufacturing of commercial plastics is carried on , in order to improve the strength, durability or grant the plastic specific characteristics. Generally , there are two kinds of commercial plastics, thermoplastic and thermosetting plastic. Thermoplastics can be reheated, melted, and molded into different shape s , while thermosetting plastic will degrade and turn into other substances if reheated after molding. The molecules of thermoplastics are pack ed together by entanglements and Van der Waals forces. When a thermoplastic is heated up, it loses its entanglements and its molecules get farther away from each other, which causes the plastic changing from solid to liquid without breaking the bonds withi n the molecules. On the other hand, the molecules of thermosetting plastic are packed together not only by entanglements and Van der Waals forces, but also by the cross – links between molecule s . When a thermosetting plastic is heated up, the cross – linking

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11 bonds between molecules break apart and the plastic turns into another substance when it melts, usually by decomposing (Callister and Rethwisch, Fundamentals of Materials Science and Engineering, 3rd Ed. 2008) Why traditional pla stics are not biodegradable The nature of traditional plastics is the reason why they cannot be biodegraded. The carbon chains of traditional plastics are too long and too well packed for microorganisms to digest, but if they are broken into small pieces the microorganisms will be able to degrade them. However, the breakdown process is too long for most of the traditional plastics, if there is no any artificial processing before being thrown in a landfill is involved . Therefore, before the plastics degrade themselves naturally, more plastics will be manufactured, causing increasing plastic pollution around the world. Types of Plastics Today, there are many different types of plastics manufactured in the plastic industry. They are applied in different areas depending on their properties. The table below summarizes names of all commonly used plastics, their properties, and application s . It shows the importan ce of plastic materials, since they are used in many different areas.

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