Thermal crosslinking of polylactide/star-shaped polycaprolactone for toughening and resistance to thermal deformation

Abstract

The applications of polylactic acid (PLA) are limited by its brittleness and poor thermal resistance. Here, the toughness of PLA and its resistance to thermal deformation were enhanced by crosslinking it with star-shaped polycaprolactone using dicumyl peroxide as a thermal initiator. The mechanical properties of the blended and crosslinked films were investigated via tensile testing. The crosslinked films of PLA/st4PCL-G exhibited toughness 1.2 times greater than that of neat PLA. The resistance to thermal deformation was investigated in a hot oven and in hot water. Although the glass-transition temperature (Tg) of the crosslinked films was lower than that of neat PLA, the crosslinked films exhibited resistance to thermal deformation and maintained shape stability without any shrinkage or distortion at temperatures greater than Tg. This work studied the crosslinking of PLA/star-shaped polycaprolactone to enhance the toughness and resistance to thermal deformation of PLA. The tensile and thermal properties of the blend and crosslinked films were investigated. The simple test of resistance to thermal deformation by immersing in hot water was done. The crosslinked film shows resistance to deforming in hot water (80\u2009°C, above its Tg).