Biodegradable polymers environmental effects

Initial photooxidation and several other factors will diminish the molecular weight of polymers thereby releasing low molecular weight portions of pol3nneric chains which eventually can be biodegraded. The total environmental effect on polymers is therefore put together by... 

The over growing environmental pressure caused by the wide spread consumption of petroleum based polymers and plastics has hastened the development of biodegradable and environmentally acceptable materials. Biopolymers derived from various natural resources such as proteins, cellulosics, starch and other polysaccharides are regarded as the alternate materials. Biodegradable polymeric materials derived from renewable sources are the most promising materials because of their easy availability and cost effectiveness. Biodegradable modified polysaccharides have been found to possess varied applications such as salt resistant absorption of water [109]. 

In the following paragraphs, different test methods for the assessment of polymer biodegradability are presented. Measurements are usually based on one of the four approaches given above, but combinations also occur. Before choosing an assay to simulate environmental effects in an accelerated manner, it is critical to consider the closeness of fit that the assay will provide between substrate, micro-organisms or enzymes, and the application or environment in which biodegradation should take place... 

Tsuji, H. and Suzuyoshi, K. (2003) Environmental degradation of biodegradable polyesters 4. Effects of pores and surface hydroplrilicity on biodegradation of poly(8-caprolactone) and poly[(R)-3-hydroxybutyrate] films in controlled seawater. Journal of Applied Polymer Science, 90, 587-593. 

What makes artificial plastics so attractive compared with long-used natural polymers such as wood, paper, cotton, wool, silk, horn, or natural rabber (caoutchouc) Synthesized plastics can be easily formed into almost any shape, they are resistant to environmental effects, heat, chemicals, and they are inexpensive (these properties, of course, differ depending on the type of plastics). Natural polymers have some advantages, too, primarily that they are typically more biodegradable than synthetic materials. As environmental pollution worsens, this property is becoming increasingly important. Humankind must use resources efficiently and must try to prevent unnecessary problems in the enviromnent. 

Knowledge of the environmental fate and ecotoxicological profile of intermediates released during biodegradation would obviously enable a better characterisation of the environmental behaviour of the overall biodegradable polymer (or plastic), and would confirm and strengthen any conclusion on the absence of ecotoxicological effects, as already inferred from the bioassays prescribed by the aforementioned standards. 

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