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

19. Thanks