ENVIRONMENTAL DEGRADATION OF PEROXIDE MODIFIED POLY(L-LACTIDE)

Poly(L-lactide) (PLLA), prepared by a tin(II)-octoate initiated ring-o pening melt-polymerization was separately modified with tert-butylpero xy benzoate (0.1, 0.25 and 0.5 wt%) in an extruder. The peroxide modif ication retarded the melt degradation and caused changes in the morpho logy of the polymer. Injection molded specimens of unmodified and pero xide modified PLLA were prepared. Changes in weight, mechanical streng th, molar mass and in the morphology were studied during degradation i n soil. The peroxide modified samples underwent a more rapid degradati on than the unmodified ones, which can be related to the morphological changes caused by the peroxide modification. The degradation behavior could mainly be related to accessibility to water. Copyright (C) 1996 Published by Elsevier Science Limited.