聚氨酯预聚体增容PLA/TPU复合材料的制备与性能

Preparation and Properties of PLA/TPU Composite by Compatibilization of Polyurethane Prepolymer

以聚乳酸(PLA)、热塑性聚氨酯(TPU)和聚氨酯预聚体(PUP)为原料,通过原位反应制备了一系列聚乳酸/热塑性聚氨酯(PLA/TPU)复合材料,并详细分析了PUP对PLA/TPU复合材料的反应原理、力学性能、断面形貌及结晶性能的影响。结果表明:随着PUP的加入,复合材料的拉伸样条出现明显的屈服和缩颈现象,当PUP含量为15%时,试样的断裂伸长率提升了382%,冲击强度是未加PUP试样的2. 1倍,拉伸强度轻微下降,另外,FTIR和SEM分析结果表明,PUP中NCO基团与PLA中末端羟基或羧基的反应显著改善了PLA和TPU共混物的相容性。结晶测试表明,PLA/TPU复合材料比纯PLA的结晶速率和晶体的完善程度都高。

Polylactic acid( PLA),thermoplastic polyurethane( TPU) and polyurethane prepolymer( PUP) were used as raw materials to prepare a series of PLA/TPU composite through in-situ reaction,and the effects of PUP on the reaction principle,mechanical properties,fracture morphology and crystallization properties of PLA/TPU composite were analyzed in detail. The result showed that,with the addition of PUP,composite’s tensile specimens exhibited pronounced yield and necking. The elongation at break increased to 382%,the impact strength was 2. 1 times of the unfilled PUP sample,the tensile strength decreased slightly. In addition,FTIR and SEM analysis showed that,the reaction of NCO groups in PUP with terminal hydroxyl or carboxyl groups in PLA significantly improved the compatibility of PLA and TPU blends. The crystallization test showed that PLA/TPU composite had a higher crystallization rate and more perfect crystal than pure PLA.