Biodegradable Polymers
With the immense popularity of plastic use, immense amount of plastics requires to be disposed off as waste. Because they do not degrade, it is causing damage to the environment and even adversely affecting the wild life population. For solving this problem, efforts are being made worldwide for developing biodegradable polymers.
American Society for Testing of Material (ASTM) and International Standards Organization (ISO) has defined degradable polymer as”those which undergo a significant change in chemical structure under specific environmental conditions”. Biodegradable polymers are those polymers which get degraded by the actions of microorganism like bacteria, fungi and algae which are present in the nature.
Plastic that is normally produced do not undergo biodegradation easily. This is because their surface in contact with the soil is generally smooth and microorganisms in the soil are unable to penetrate this surface. This type of plastic has an impenetrable matrix made from petroleum and reinforced by inorganic materials.
Another type of polymer has been developed which has a conventional petroleum based matrix surrounded by fibres made from natural products. After disposal of these products, the microorganisms attack the natural fibres within the matrix. That makes the material weaker with open edges opening the way for farther degradation.
Finally, efforts are being made to produce plastics which are completely biodegradable. The matrix of this plastic material produced using natural products like starch and using flax or hemp as fiber reinforcement. Microorganisms are able to consume completely such plastic leaving only carbon dioxide and water in its place.
This entry was posted on Thursday, July 17th, 2008 at 12:32 pm and is filed under Polymers. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.