基于熔融沉积成型的聚乳酸/热塑性聚氨酯的制备与表征

Preparation and Characterization of Poly( lactic acid)/Thermoplastic Polyurethane Based on Fused Deposition Modeling

通过熔融共混法制备了不同质量比的聚乳酸(PLA)/热塑性聚氨酯(TPU)共混物。采用旋转流变仪、扫描电镜、电子万能试验机及差示扫描量热仪等研究了共混物的动态流变行为、微观形貌、力学性能和热性能,并通过线材机牵引成直径为1.75 mm左右的线材进行熔融沉积成型(FDM)。结果表明,加入TPU后能提高材料的储能模量,使熔体弹性增强,利于熔融铺丝。TPU能改善材料的冲击韧性,且随着TPU含量的增加而增大。另外,PLA/TPU熔融共混后体系的结晶能力下降,对熔融沉积成型收缩翘曲具有抑制作用。当TPU质量分数为10%时,线材的熔融沉积成型效果最好。

Poly（ lactic acid）（ PLA）/thermoplastic polyurethane（ TPU） blends with different mass ratios were prepared by melt blending. The dynamic rheological behavior,mechanical properties,microstructure and thermal performance of the blends were investigated by rotational rheometer,electronic universal testing machine,SEM and differential scanning calorimeter（ DSC）. The pellets of blends were drawn into filaments with a diameter of about 1. 75 mm through a single screw extruder to carry out fused deposition modeling（ FDM）. The results show that the storage modulus and elasticity of blends are enhanced by adding TPU,which is beneficial to melt-laying. The impact toughness of blends can be increased with introduction of TPU. In addition,the shrink and warp of models by FDM are inhibited,which is due to the decline of crystalline ability after blending. The filament shows the best property resulting is 10% of TPU in the blends via FDM method.