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ABSTRACT:
Biodegradable polymers are a newly emerging field. Biodegradable polymers are useful for various applications in medical, agriculture, drug release and packaging fields.Biodegradable polymers have received much more attention in the last decades due their potential applications in the fields related to environmental protection and the maintenance of physical health. At present only few groups of the mentioned biopolymers are of market importance. The main reason is their price level, which is not yet competitive. The future of each biopolymer is dependent not only on its competitiveness but also on the society ability to pay for it. The future outlook for development in the field of biopolymers materials is promising.To improve the properties of biodegradable polymers, a lot of methods have been developed, such as random and block copolymerization or grafting. These methods improve both the biodegradation rate and the mechanical properties of the final products. Physical blending is another route to prepare biodegradable materials with different morphologies and physical characteristics.To provide added value to biodegradable polymers, some advanced technologies have been applied.
KEYWORDS: Biodegradable polymers; biodegradation and bioerosion, polyesters; polyamides, designing of biodegradable polymers etc.
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1.INTRODUCTION:
Biodegradable polymers are a newly emerging field. A vast number of biodegradable polymers have been synthesized recently and some microorganisms and enzymes capable of degrading them have been identified. In developing countries, environmental pollution by synthetic polymers has assumed dangerous proportions. As a result, attempts have been made to solve these problems be including biodegradability into polymers in everyday use through slight modifications of their structures. [1]
One of the first problems to become apparent while over viewing the literature in this area is the fact that there are varying definition of 'biodegradation' and 'bioerosion. Ikada defines biodegradable polymers as those, which are degraded in these biological environments not through thermal oxidation, photolysis, or radiolysis but through enzymatic or non-enzymatic hydrolysis. [1] Williams [2] defines biodegradation as biological breakdown of polymeric material, as opposed to simple hydrolytic breakdown, a definition also held by Gilbert et al. [3] Gilding, on the other hand, reports that the phrase 'biodegradable polymer' is widely used for any polymer that undergoes in vivo degradation. [4] Graham and Wood define biodegradable system as those, which degrade after a...