Plastic bottles, plastic spoons, plastic packaging, plastic bags… we use a lot of plastic. Plastics are made from polymers, which are super long chains of atoms. We love them because they’re cheap and super sturdy for how light they are. The problem is that they’re so sturdy that, after we throw them away, they can sit around in a landfill for a million years. Almost all plastics we use come from petroleum products, but recently more is being made from corn starch which has a compact structure which can be used as a plastic.
Since corn starch is often used and cannot be easily found in Dipolog City, we thought of another replacement for it that can meet its standards and can easily be found, which is the cassava starch. The cassava root is long and tapered, with a firm, homogeneous flesh encased in a detachable rind, about 1mm thick, rough and brown on the outside. Commercial varieties can be 5 to 10 cm in diameter at the top, and around 15 cm to 30 cm long.
A woody cordon runs along the root’s axis. The flesh can be chalk-white or yellowish.
Cassava roots are very rich in starch, and contain significant amounts of calcium (50 mg/100g), phosphorus (40 mg/100g) and vitamin C (25 mg/100g). However, they are poor in protein and other nutrients. In contrast, cassava leaves are a good source of protein, and are rich in the amino acid lysine, though deficient in methionine and possibly tryptophan. These components are components of biodegradable plastic.
1. 2. Objectives of the Study The main objective of the study is to formulate a ‘biodegradable’ plastic material using cassava starch.
The study also aims to determine the amount of time the plastic will decompose with the use of cassava starch. The study furthermore aims to also determine the loading capacity of the plastic when used as a carrier and or holder of a given volume of materials. 1. 3. Significance of Study This study is important to be able to help Mother Earth in reducing its pollutants and toxic or harmful wastes. Through this study, the researchers will be able to help other people, the animals and the environment. The researchers would like to stop plastic pollution and be part of the solution.
Plastic bags and bottles, like all forms of plastic, create significant environmental and economic burdens. Biodegradable plastics could be an effective solution to all of the pollution problems. Biodegradable plastics are a much better choice than non biodegradable plastics because they are friendlier to the earth and the environment. Biodegradable plastics break down faster, can be recycled easier and are non-toxic. With these characteristics of biodegradable plastics, we could help save lives and the environment as well. 1.
4. Scope and Limitation of the Study This experiment only covers plastic bags, not including other plastic materials such as plastic containers, plastic cups, straws and other plastic utensils. Most of the materials used in the experiment are accessible and can be bought in supermarkets. However, there are a few which are not available in nearby stores. Premix Polyester Resin and Polymer MEKP Hardener are manufactured by Polymer Products (Phil) Inc. and can be bought in Bagong Ilog, Pasig City. 1. 5. Definition of Terms Polymers
– A substance that has a molecular structure built up chiefly or completely from a large number of similar units bonded together. Petroleum – A liquid mixture of hydrocarbons that is present in suitable rock strata and can be extracted and refined to produce fuels. Amino Acid – Important organic compounds made from amine and carboxylic acid functional groups, along with a side-chain specific to each amino acid. Lysine – An ? -amino acid with the chemical formula HO2CCH(CH2)4NH2. It is an essential amino acid for humans. Methionine – An ?
-amino acid with the chemical formula HO2CCHCH2CH2SCH3. This essential amino acid is classified as nonpolar. Tryptophan – One of the 22 standard amino acids and an essential amino acid in the human diet. Biodegradable – Capable of being decomposed by bacteria or other living organisms. Decompose – Decay; become rotten. Polyester Resin – Unsaturated resins formed by the reaction of dibasic organic acids and polyhydric alcohols. 2 Review of Related Literature Research has been done on biodegradable plastics that break down with exposure to sunlight (e. g.
, ultra-violet radiation), water or dampness, bacteria, enzymes, wind abrasion and some instances rodent pest or insect attack are also included as forms of biodegradation or environmental degradation. It is clear some of these modes of degradation will only work if the plastic is exposed at the surface, while other modes will only be effective if certain conditions exist in landfill or composting systems. Starch powder has been mixed with plastic as a filler to allow it to degrade more easily, but it still does not lead to complete breakdown of the plastic.
Some researchers have actually genetically engineered bacteria that synthesize a completely biodegradable plastic, but this material, such as Biopol, is expensive at present. The diversity and ubiquity of plastic products substantially testify to the versatility of the special class of engineering materials known as polymers. However, the non-biodegradability of these petrochemical-based materials has been a source of environmental concerns and hence, the driving force in the search for ‘green’ alternatives for which starch remains the frontliner.
Starch is a natural biopolymer consisting predominantly of two polymer types of glucose namely amylose and amylopectin. The advantages of starch for plastic production include its renewability, good oxygen barrier in the dry state, abundance, low cost and biodegradability. The longstanding quest of developing starch-based biodegradable plastics has witnessed the use of different starches in many forms such as native granular starch, modified starch, plasticized starch and in blends with many synthetic polymers, both biodegradable and non-biodegradable, for the purpose of achieving cost effectiveness and biodegradation respectively.
In this regard, starch has been used as fillers in starch-filled polymer blends, thermoplastic starch (TPS) (produced from the combination of starch, plasticizer and thermomechanical energy), in the production of foamed starch and biodegradable synthetic polymer like polylactic acid (PLA) with varying results. However, most starch-based composites exhibit poor material properties such as tensile strength, yield strength, stiffness and elongation at break, and also poor moisture stability.
This therefore warranted scientific inquiries towards improving the properties of these promising starch-based biocomposites through starch modification, use of compatibilizers and reinforcements (both organic and inorganic), processing conditions, all in the hope of realizing renewable biodegradable substitutes for the conventional plastics. (images. marieeeeeeeeeeeeeeel. multiply. multiplycontent. com/)