Amorphous biodegradable polyesters

Modelling degradation of amorphous biodegradable polyesters basic model... 

Synthetic biodegradable polyesters fall into two broad categories. One is highly amorphous, imparting flexibility and clarity comparable to a conventional LDPE copolymer. A second group of semicrystalline polyesters is more rigid, with properties similar to PET, PP, or PS. 

Polylactide is a kind of biodegradable polyester that possesses many desirable properties such as non-toxicity, hydrolyzability and biocompatibility for use for varied biomedical purposes such as sutures, fracture fixation, oral implant and drug delivery microspheres.It is popularly synthesized by the ringopening polymerization of lactide monomers which are the cyclic dimers of lactic acid. Polymerization of racemic D,L-lactide typically results in atactic, amorphous polymers named poly(D,L-lactide) (rg 60 °C), whereas polymerization of L-lactide or D-lactide results in isotactic, semicrystalline polymers called poly(L-lactide) or poly(D-lactide) (7" 180 PLA fractures... 

Later work by Suzuki and Tokiwa(55,56,57) in which they evaluated the stability of polyesters to lipases confirmed the work of Potts. Potts(58) demonstrated the biodegradation of polycaprolactone which he used in the fabrication of agricultural articles, such as plant pots. J. P. Kendnck(59) demonstrated that amorphous regions of polyesters were more readily biodegraded than crystalline regions. 

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