Effects of Triacetin Addition on the Thermal and Mechanical Properties of Poly(L-lactic acid)/Polycarbonate Blends

초록

In order to enhance the poor impact strength and low elongation-at-break of poly(L-lactic acid) (PLA), PLA/poly(bisphenol A carbonate) (PC) and PLA/PC/triacetin (TA) blend films were prepared by a melt-blending process. Thermal and mechanical properties of the blend films were analyzed by using a universal testing machine, impact strength tester, scanning electron microscope, differential scanning calorimeter, and dynamic mechanical analyzer. Results showed that there was no miscibility between PLA and PC polymers. The crystallization of PLA in PLA/PC blends become different and the PLA crystals formed were imperfect. Addition of TA to PLA(70)/PC(30) blends made the crystallization of PLA easier compared to PLA(70)/PC(30) blends. Although the tensile breaking stress of PLA/PC films decreased as the PC content increased, the elongation-at-break and impact strength of the PLA/PC blend films were not enhanced. However, both elongation-at-break and impact strength of PLA(70)/PC(30)/TA films increased dramatically with increasing TA content without decreasing tensile breaking stress, indicating that TA acted as an excellent compatibilizer in PLA/PC blends.

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