Isothermal Crystallization Behaviour and Mechanical Properties of Poly(L-lactic Acid)/Talc/Ethylene bis-Stearamide Composites

Abstract

Talc is very effective on the enhancement of crystallization of poly(L-lactic acid) (PLLA) and can retain fine mechanical properties with addition of ethylene bis-stearamide (EBS), thus, PLLA/ talc/EBS composites were prepared to improve the crystallization rate and retain fine mechanical properties of material. Compared to the neat PLLA at 110 ºC, upon the addition of 10 % talc and 3 % EBS, the induction period of poly(L-lactic acid) decreased from 4.0-0.4 min and half time of overall crystallization decreased from 10-1.8 min at 101 ºC. The Avrami theory was used to describe the kinetic of isothermal crystallization of PLLA/talc/EBS composites. PLLA/talc/ EBS composites not only take a heterogeneous nucleation process followed by a three-dimensional crystal growth but also have other complicated nucleation mechanism. Scanning electron microscopy showed that addition of talc enhanced compatibility between poly(L-lactic acid) and ethylene bis-stearamide. The mechanical results showed that addition of high content of talc significantly weakened the mechanical properties of biodegradable poly(L-lactic acid). However, Adding ethylene bis-stearamide to poly(L-lactic acid)/talc composites can retain fine mechanical properties of biodegradable poly(L-lactic acid).