IMPROVEMENT IN MECHANICAL PROPERTIES OF FLEXIBLE POLY(L-LACTIDE)-b-POLYETHYLENE GLYCOL-b-POLY(L-LACTIDE) BIOPLASTIC BY MELT BLENDING WITH BORON NITRIDE

Abstract

Poly(L-lactide)-b-polyethylene glycol-b-poly(L-lactide) triblock copolymer (PLLA-PEG-PLLA)/boron nitride (BN) composites with BN contents of 1, 2 and 4 wt.% were prepared by melt blending. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and tensile testing were carried out to characterize the phase morphologies, thermal properties and mechanical properties of composite films. The BN particles showed good distribution and dispersion throughout the film matrices as observed from SEM. DSC analysis showed that increasing crystallinity content and decreasing half crystallization-time of PLLA-PEG-PLLA/BN composites were obtained when the BN content was increased. The ultimate tensile stress significantly increased and strain at break steadily decreased with an increase in the BN content. These results showed that the BN particles enhanced crystallizability and mechanical properties of PLLA-PEG-PLLA.