抄録
In this study polylactic acid(PLA) was used as a biodegradable plastic. Plastic sheets of PLA were rolled with the reduction ratio of 25 to 75% and at the temperature of 70 to 100°C. Tensile and bending test were carried out for rolled sheets. Both of tensile and bending strength in rolling direction were increased with increase of rolling reduction. The tensile strength and Young’s modulus of the rolled biodegradable plastics were 1.6 times and 1.7 times higher as compared with the non-rolled plastics, respectively. Effects of rolling on microstructure were observed with X-ray diffraction, polarization microscope, and differential scanning calorimeter(DSC). Consequently, relationships of mechanical properties with orientation of molecular chains and crystallization of the polymer were made clear.
