Abstract
The effects of the annealing and Poly(e-caprolactone) (PCL) content ratio on the stress-strain curves of poly(L-lactic acid) (PLLA) was examined. Specimens were made using a melt-mixer and a hot press. After observation of cryo-fractured surfaces of specimens, the stress-strain curves were measured using universal testing machine. In the compressive tests, the yield stress of PLLA increased with annealing time. The peaks near the elastic limit of stress-strain curves of annealed PLLA were not observed. In order to calculate the crystallinity of annealed PLLA, differential scanning calorimetry curves (DSC curves) of specimens were measured. When PCL was added, the yield stress and Young's modulus of quasi-static compressive tests were deceased with increasing PCL content. In particular, the drastic change of yield stress between PLLA:PCL=50:50 and PLLA:PCL=30:70 was observed.
