Recycling environmentally degradable

Hie ester linkage of aliphatic and aliphatic-aromatic copolyesters can easily be cleaved by hydrolysis under alkaline, acid, or enzymatic catalysis. This feature makes polyesters very attractive for two related, but quite different, applications (i) bioresorbable, bioabsorbable, or bioerodible polymers and (ii) environmentally degradable and recyclable polymers. 

As a partial solution to the global issue of plastic waste, in recent years much interest has been devoted to the formulation of environmentally degradable plastic materials. In particular the use of natural polymers presents several advantages such as biodegradability, utilizing of renewable resources, recyclability. At the same time water sensitivity and degradability of natural polymers limit their possible applications. Consequently bioplastics cannot replace synthetic plastics in every application but they can result appropriate in specific products especially for those applications in which recovery of plastics is not economically feasible, viable and... 

For safe disposal of the products without any adverse effects to the environment, such as recycling and subsequent repolymerization, recycling to olefinic feedstock by pyrolysis, continued burial in landfill sites, incineration, and use of environmentally degradable polymers... 

Today, starch is inexpensive and is available annually from com and other crops, and is produced in excess of current market needs in the United States and Europe (1). Starch is totally biodegradable in a wide variety of environments and could permit the development of totally degradable products for specific market demands. Degradation or incineration of starch products would recycle atmospheric CO2 trapped by starch-producing plants and would not increase potential global warming (2) (see also Environmentally Degradable Plastics). 

FuUer, M. (2005) Technical survey of environmentally degradable plastics. Proceedings of Sustainable Plastics Biodegradability versus Recycling, Manchester UK. 

Greene, J. (2007a) Rerformance Evaluation of Environmentally Degradable Elastic Packaging and Disposable Service Ware. Cal Recycle Publications, http //www. calrecycle.ca.gov/Publications/Documents/Plastics/43208001. pdf (last accessed June 2007). 

In fact, the properties of these polymers can be tailored by controlling the carbon feed. They are recyclable and degrade into CO2 and water. In addition, these polymers are also biocompatible. It is because of these reasons that PH As are becoming increasingly popular as environmentally friendly materials with industrial, agricultural and medical applications. ... 

This was brought on by the growing pressure to avoid or reduce environmental pollution from waste polymers and plastics, which were accumulating widely on land and in oceans due to careless disposal, and because of the decreasing availability of landfill space for controlled disposal. Options available then, and now, were landfill, incineration, recycle, and controlled environmental degradation. Environmental degradation at that time was almost always referred to as biodegradation... 

The rate at which the catalyst is lost or degrades has a major influence on the design. If degradation is rapid, the catalyst needs to be regenerated or replaced on a continuous basis. In addition to the cost implications, there are also environmental implications, since the lost or degraded catalyst represents waste. While it is often possible to recover useful materials from degraded catalyst and to recycle those materials in the manufacture of new catalyst, this still inevitably creates waste, since the recovery of material can never be complete. 

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