2003 Volume 59 Issue 7 Pages 272-277
The blend film of poly l-lactic acid (PLLA) added with triacetin (TAC) was prepared by using a solvent cast technique. The blend film exhibits elastomeric property owing to the plasticization effect of TAC. In order to investigate the degradation mechanism of the blend film under load and hydrolysis conditions, we performed the strip bend test and the environmental stress cracking(ESC) test in aqueous NaOH solutions. The following conclusions are deduced from the observed result: (i) the degradation mechanism under load conditions is different from that under no-load conditions, (ii) the fracture behavior of PLLA film can be analyzed by linear fracture mechanics, (iii) annealing decreases ESC resistance of PLLA, and (iv) the addition of TAC to PLLA enhances ESC resistance.