Effects of heat treatment on the thermal and mechanical properties of ramie fabric-reinforced poly(lactic acid) biocomposites

Abstract

Laminated biocomposites based on ramie fabric and poly(lactic acid) were prepared through hot compression molding followed by direct cooling (without heat treatment) or melt crystallization (with heat treatment). The effects of heat treatment and ramie fabric reinforcement on the thermal and mechanical properties of poly(lactic acid) composites were studied. X-ray diffraction and differential scanning calorimetry measurements confirmed that the heat treatment was able to promote the formation of crystals and enhance the crystallinity of poly(lactic acid), and the addition of ramie fabric also accelerated the crystallization rate of poly(lactic acid). Hence, heat treatment and ramie fabric reinforcement both can improve the thermal stability of poly(lactic acid) biocomposites remarkably. The heat deflection temperature of poly(lactic acid)/24 wt% ramie fabric biocomposite with heat treatment was up to 149.3℃, with a highest increase of 90.7℃. The mechanical properties of the ramie fabric-reinforced poly(lactic acid) biocomposites were also improved after heat treatment.