Poly biodegradation mechanism

PVAc, PVA and PVB homopolymers as well as the different copolymers mentioned above all have a similar chemical motif in common. They exhibit an all carbon-carbon single bond backbone, which needs to be broken at some point in a potential biodegradation mechanism. With respect to the backbone, poly(vinyl ester)s are closely related to poly(olefin)s, poly(styrene)s and poly(acrylate)s. These three are known not to be biodegradable. Instead, they usually decompose by the impact of UV radiation, oxidation and hydrolysis reactions, which are not considered to be biological degradation. 

Schubert, M. A., Wiggins, M. J., Schaefer, M. R, Hiltner, A. Anderson, J. M. (1995) Oxidative biodegradation mechanisms of biaxially strained poly(etherurethane urea) elastomers. Journal of Biomedical Materials Research, 29, 337—347. 

PLA fibers are not only biodegradable but also highly functional due to their intrinsic properties such as bacteriostatic, flame-retardant, and weathering resistance [3, 4], when compared with conventional poly(ethylene terephthal-ate) (PET) fibers. In this chapter, biodegradation mechanism, the key performance features, and potential applications of PLA fiber/nonwoven products are discussed [5, 6]. 

Poly(e-caprolactone) (PCL) is a synthetic polymer which has many advantages biodegradability mechanical properties similar to polyolefins hydrolysability similar to polyesters compatibility with many other polymers ease of melt... 

Polyesters, polycarbonates and poly(amino acids)s can be synthesized and chemically recycled by novel enzyme-catalyzed polymerization and degradation methods, and these technologies will be realized as a sustainable chemical industry in the near future (Fig. 14.26). Based on these considerations, extensive studies of the biodegradation mechanisms should be further carried out in detail. 

The biodegradation of poly(alkylene glycols) is hindered by their lack of water solubiUty, and only the low oligomers of poly(propylene glycol) are biodegradable with any certainty (179—181), as are those of poly(tetramethylene glycol) (182). A similar xo-oxidation mechanism to that reported for poly(ethylene glycol) has been proposed. 

Nanocapsules of biodegradable polymers, such as PLA and PLA copolymers or poly (e-caprolactone), have been prepared by an interfacial polymer deposition mechanism [163-166], An additional component, a water-immiscible oil, is added to the drug-polymer-solvent mixture. A solution of the polymer, the drug, and a water-immiscible oil in a water-miscible solvent such as acetone is added to an external... 

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