Biodegradable plastics

ENGINEERING STUDENTS PRESENTATION

1. Welcome

2. Biodegradable Plastics Submitted by Drisya DS S5 Civil Register No. 16010159

3. ABSTRACT The biodegradable plastics production in Thailand, emphasizing the potential contribution of cassava starch in these products. Types of biodegradable  plastics and their manufacturing processes are described. The major types of biodegradable plastics discussed are directly-expanded starch products and various starch-polymer blends (PCL, PLA, PVA and PHA). Research focusing on cassava on cassava starch incorporation into biodegradable plastics is plastics is summarized.

4. INTRODUCTION Plastics designed to degrade comparatively quickly include oxo -degradable and UV degradable polymers that break down when exposed to oxygen or light respectively. . To qualify as bio-degradable, however, this degradation has to happen, at least in part, due to cell mediated phenomena or microorganisms. As a result the polymer is eventually reduced to water, carbon dioxide, biomass and possibly methane. To be considered as compostable it must meet some strict criteria as defined in national and international standards: Biodegrade : break down into carbon dioxide, water and bio mass. Disintegrate ; after three months composting and subsequent sifting through a 2 mm sieve no more than 10% residue may remain . Eco toxicity: the bio-degradation does not produce any toxic material and the compost can sustain plant growth.

5. What is a biodegradable plastic ? Firstly, it is an environmental-friendly plastic. It does not cause any harm or destruction to our environment. Secondly, it can be decompose, unlike typical and standard plastics. For example , they can easily decompose in natural environments such as composting and landfill environments . Thirdly, it would not harm human’s health when these plastic decompose into the soil.

6. Manufacturing process technology This kind of product is known also as “Gelatinized starch puff” or “Plate expanded  by extrusion” or “Baking with water”. The products are formed by the swelling and expansion of starch through the action of high temperature and water vapor.

7. Why does biodegradable plastic differ from other plastic ? There are a lot of different plastics with different properties, but the main reason plastics are non-biodegradable is because the chains of molecules called polymers that make up the plastic are too long and the bonds between the molecules are very strong to be broken down. So they will eventually be broken down, but it takes a lot longer than biodegradable materials .

8. Design concept of biodegradable plastic

9. What does science say about biodegradable plastic ? Biodegradable plastic is a plastic that decompose in natural environment; aerobic (composting) and anaerobic (landfill) environment. It is a durable and degradable plastic. Biodegradable plastics typically are produced in two forms: injection molded (solid, 3D shapes), typically in the form of disposable food service items, and films, typically sold as collection bags for leaves and grass trimmings, and agricultural mulch . In the United States, ASTM International is the authoritative body for defining biodegradable standards . The current ASTM standards are defined as standard specifications and standard test methods. Standard specifications create a pass or fail scenario whereas standard test methods identify the specific testing parameters for facilitating specific biodegradable tests on plastics .

10. Applications Biodegradable plastics are a new generation of polymers emerging in the market. Biodegradable plastics have an expanding range of potential applications, and are driven by the growing use of plastics in packaging and the perception that biodegradable plastics are 'environmentally friendly', their use is predicted to increase. However , issues are also emerging regarding the use of biodegradable plastics and their potential impacts on the environment and effects on established re cycling systems and technologies.

11. Extrusion process of biodegradable plastic.

12. Biodegradable Plastics Products

13. Advantages 1. Bioplastics Are Renewable 2. Biodegradable Plastics Break Down Faster 3. Biodegradable Plastics Are More Environmentally Friendly 4. Bioplastics Can Be Recycled Easier 5. Producing Bioplastics Requires Less Energy 6. Bioplastics Reduce Foreign Oil Dependence 7. Biodegradable Plastics Are Not Toxic

14. Disadvantages Under proper conditions biodegradable plastics can degrade to the point where microorganisms can metabolise them. Degradation of oil-based biodegradable plastics may release of previously stored carbon as carbon dioxide. Starch-based bioplastics produced from sustainable farming methods can be almost carbon neutral but could have a damaging effect on soil, water usage and quality, and result in higher food prices.

15. Biodegradable Plastic in the world ? We can find these biodegradable plastics in any store that subscribe and sell these things. But usually , if we buy online, it would be cheaper. The famous online store for this would be Alibaba.com . Most of the biodegradable plastics that sell through internet service would be from China (mainland) and Hong Kong.

16. Conclusion We can help by use less plastic and use more biodegradable plastic. As we do so, we can save environment from being destroyed but unneeded chemical substances. Soon, the use of biodegradable plastics will be globalised and people should take more attention to it by support any programme regarding biodegradable plastics .

17. REFERENCES Chollakup , R., S. Chotineeranat , K. Piyachomkwan , Y. Prachasitthisak and K. Sriroth . 1999a. Effect of gamma radiation on cassava starch, polycaprolactone and mechanical properties of their  biodegradation blends.  In: Biotechnology for a Self-sufficient Economy. Proc. of the 10th Annual Meeting of the Thai Society for Biotechnology, and the Annual Meeting of the National Center for Genetic Engineering and Biotechnology, held in Bangkok, Thailand. Nov 25-27, 1998. Chollakup , R., A. Jarerat and K. Sriroth . 1999b. Inclusion of silk protein in cassava starch and   polycaprolactone blend.  In: Proc. of the 5th Asia-Pacific Biochemical Engineering Conference and the 11th Annual Meeting of the Thai Society for Biotechnology, held in Phuket, Thailand.  Nov 15-18, 1999. p.173 . Daniell , H. and C. Guda . 1997. Biopolymer production in microorganisms and plants. Chemistry and Industry. July 1997 . Sakai, K., N. Hamada and N.Y. Watanabe. 1987. Identification and characteristics of a poly (vinyl alcohol) – degrading bacterium. Kagaku to Kogyo 61: 372-377 . Tokiwa , Y., A. Iwamoto and M. Koyama. 1990a. Development of biodegradable plastics containing polycaprolactone and/or starch. Polymer Preprints American Chemical Society, Division of Polymer Materials Science and Engineering 63: 742-746

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19. Thanks