Friday, October 18, 2019

Biodegradability of polymers Term Paper Example | Topics and Well Written Essays - 750 words

Biodegradability of polymers - Term Paper Example The degradable products are biogas, carbon dioxide and methane. Natural polymers such as polysaccharides, proteins and nucleic acid are degraded by hydrolysis and oxidation. Biodegradation can occur aerobically and anaerobically depending on the availability of oxygen. Chemical structure, physical properties, molecular weight, porosity, elasticity and morphology are responsible for a material’s biodegradation. Compounds which can be biodegradable have the power to break down in environments where the material is decomposed by biological processes with the production of water, carbon dioxide and carbon containing soil (Leja and Lewandowicz 256). There are various tests which can be performed to assess the biodegradability of polymers. The tests performed can be simple or complex depending on their duration of action. Simple tests are rapid and complex ones are slow. The test methods that are practiced are different. Plate testing method is a simple method used as an initial test. The polymer that is to be tested is set on a mineral salt agar accompanied with some carbon for fungal growth to start. Then the sample is inoculated by fungi such as Aspergillusniger. The level of biodegradability is measured by loss of dry weight and surface colonization. Another method for assessment is the enzyme test. In this method specific enzymes are used to catalyze polymers such as starch-blended polymers. The polymer of choice is inserted into an enzyme solution and is incubated. The degree of biodegradability is measured by weight loss of polymer. Another method is when various microbial consortia or groups are identified for various po lymers. This test gives its assessment by showing changes in molecular weight and mechanical properties. Modified sturm test is a simple method in which activated sewage sludge is used. The desired

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