关键词: 聚乳酸, 热塑性聚氨酯, 拉伸速率, 力学行为, 形态演化

Abstract: A series of poly(lactic acid) (PLA)/thermoplastic polyurethane (TPU) blends were prepared by melt compounding with a twin-screw extruder. A universal testing machine, impact testing machine, dynamic mechanical analyzer (DMA) and scanning electron microscope (SEM) were used to test the tensile property, impact strength, dynamic thermo-mechanical property and morphology of PLA/TPU blends, respectively. The results indicated that the elongation at break, impact strength and loss modulus of PLA/TPU blends increased distinctly with increasing TPU content, and the morphology of fracture surfaces present a change from droplets to thick fibers and thin fibers. Moreover, compared with pure PLA, the elongation at break and impact strength increased by 300 % and by a factor of 13.5 for the blend containing 40 wt % TPU, respectively.

Key words: poly(lactic acid), polyurethane thermoplastic, drawing rate, mechanical behavior, morphology