CITRATE ESTERS AS PLASTICIZERS FOR POLY(LACTIC ACID)

Citrate esters were used as plasticizers with poly(lactic acid)(PLA). Films were extruded using a single-screw extruder with plasticizer con tents of 10, 20, and 30% by weight. All of the citrate esters investig ated were found to be effective in reducing the glass transition tempe rature and improving the elongation at break. It was observed that the plasticizing efficiency was higher for the intermediate-molecular-wei ght plasticizers. Hydrolytic and enzymatic degradation tests were cond ucted on these films. It was found that the lower-molecular-weight cit rates increased the enzymatic degradation rate of PLA and the higher-m olecular-weight citrates decreased the degradation rate as compared wi th that of unplasticized PLA. (C) 1997 John Wiley & Sons, Inc.