Biodegradation of polyamides

Oppermann FB, Fickaitz S, Steinbiichel A (1998) Biodegradation of polyamides. Polym Degrad Stab 59 337-344... 

Recently the biodegradability of polymers has become very important to the chemical industry and society in general. Chapter 19 describes studies on the biodegradability of polyamides by a number of bacteria. 

Oppermann F B, Pickartz S, Steinbuchel A (1998), Biodegradation of polyamides . Polymer Degradation and Stability, 59, 337-344. 

Heteroatom Chain Backbone Polymers. This class of polymers includes polyesters, which have been widely studied from the initial period of research on biodegradable polymers, polyamides, polyethers, polyacetals, and other condensation polymers. Their linkages are quite frequendy found in nature and these polymers are more likely to biodegrade than hydrocarbon-based polymers. 

The susceptibility of CPAEs to hydrolysis by R. delemar lipase decreased with the shortening of the polyamide blocks and with increasing polyamide content (Figure 10). The simple blends of nylon and PCL at 270 °C for 10 min retained high biodegradability of PCL. 

Hydrolytic reactions, which are best documented, include saponification of esters, hydrolysis of amides, and hydrolysis of ethers (glycosides). Except for ester saponification, all the other reactions proceed at a measurable rate only by enzymic catalysis. Hydrolytic enzymes are regular constituents of the digestive tract and lysosomes. They are responsible for the biodegradation of polyesters, polyamides (including polypeptides), polysaccharides and, probably, polyurethanes. 

These stabilized membrane systems on the basis of polyamides are biodegradable and therefore have a great potential use for in vivo applications. 

Kawasaki, N., Nakayama, A., Yamano, N., Takeda, S., Kawata, Y, Yamamoto, N., and Aiba, S. [2005]. Synthesis, thermal and mechanical properties and biodegradation of branched polyamide 4, Polymer, 46,9987-9993. 

Their liability to biodegradation is comparable to that of polyesters and polyamides with differences in their biodegradation rates. Generally, biodegradability of polyurethanes is dependent on whether the pre-polymer is polyester or polyether. 

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