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通过熔融共混制备了聚L-乳酸(PLLA)和热塑性聚氨酯(TPU)的共混物,并研究了该PLLA/TPU共混挤出物的流变性能及聚集态结构。结果表明:该PLLA/TPU共混物为假塑性流体,随着共混体系中TPU含量的增加,共混物熔体的表观黏度提高,且非牛顿指数减小,即共混物的黏度对剪切速率的敏感性增强;另外,随着剪切速率或TPU含量的增加,PLLA/TPU共混挤出试样的结晶度呈下降趋势,其断裂强度与模量亦有所降低,而断裂伸长率则有所提高。
The blends of poly (L-lactic acid) (PLLA) and thermoplastic polyurethane (TPU) were prepared by melt blending. The rheological properties and aggregated structure of the PLLA / TPU blends were studied. The results show that the PLLA / TPU blends are pseudoplastic fluid. With the increase of TPU content in the blends, the apparent viscosity of the melt increases and the non-Newtonian index decreases, that is, the viscosity of the blends The sensitivity to shear rate is enhanced. In addition, the crystallinity of PLLA / TPU blends decreases with the increase of shear rate or TPU content, and the fracture strength and modulus decrease Elongation at break increased.