Preparation and Mechanical Properties of Poly (lactic acid)/Montmorillonite Nanocomposites

摘要

In this paper, poly (lactic acid) (PLA)/ montmorillonite (MMT) composites were prepared on HAAKE Torque Rheometer with different processing temperature and rotate speed. Based on the results of tensile properties of the composites, the optimum processing conditions: 145℃, 80r/min were obtained. WAXD measurements for the samples prepared under optimum processing conditions were performed. WAXD results show that a strong diffraction peak appeared at 20=3.62° for MMT sample, while this diffraction peak is very weak and only a small shoulder remains in the PLA / MMT composites prepared, which indicates the original ordering of MMT is destroyed during processing. The less content of MMT in the composite, weaker the diffraction peak, that is, less ordered layers coherence of the MMT in the composites. The tensile properties of the samples show that the modulus of PLA / MMT nanocomposite increased greatly, comparing with that of the pure PLA, but the tensile strength and the break elongation of the composites decreased to some extent.