Mechanical Properties and Morphology of Polylactide, Linear Low-Density Polyethylene, and Their Blends

Melt blending of linear low density polyethylene (LLDPE) and polylactide (PLA) was performed in an extrusion mixer with post extrusion blown film attachment with and without compatibilizer-grafted low density polyethylene maleic anhydride. The blend compositions were optimized for tensile properties as per ASTM D 882-91. On the basis of this, LLDPE 80 [80 wt % LLDPE and 20 wt % poly(L-lactic acid) (PLLA)] and MA-g-low-density polyethylene 80/4 (80 wt % LLDPE, 20 wt % PLLA, and 4 phr compatibilizer) were found to be an optimum composition. The blends were characterized according to their mechanical, thermal, and morphological behavior. Fourier transform infrared spectroscopy revealed that the presence of compatibilizer enhanced the blend compatibility to some extent. The morphological characteristics of the blends with and without compatibilizer were examined by scanning electron microscopy. The dispersion of PLLA in the LLDPE matrix increased with the addition of compatibilizer. This blend may be used for packaging applications. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 496-502, 2010