MDI原位增容PBT/TPU共混物的研究

Study on In-Situ Compatibilization of PBT/TPU Blends with MDI

以二苯基亚甲基二异氰酸酯(MDI)为原位增容剂,通过熔融共混法制备了不同MDI含量的聚对苯二甲酸丁二酯/热塑性聚氨酯(PBT/TPU)共混物,并对其化学结构、力学性能、微观形貌和结晶性能进行研究。结果表明:MDI可以有效改善PBT和TPU之间的相容性;随着MDI含量增加,PBT/TPU共混物的拉伸强度增大,断裂伸长率和缺口冲击强度则先增大后减小;当MDI质量分数为1.0%时,共混物的断裂伸长率和缺口冲击强度分别达到304%和31.0kJ/m^(2),与不含MDI的共混物相比分别提高了591%和308%。MDI的加入会使PBT/TPU共混物的结晶度下降,但不改变其晶体结构。

Polybutylene terephthalate/thermoplastic polyurethane(PBT/TPU)blends with different contents of diphenylmethylene diisocyanate(MDI)were prepared by meltmixing using MDI as in-situ compatibilizer.The chemical structure,mechanical properties,micro-morphology and crystallinity of PBT/TPU blends were studied.The results show that MDI can effectively improve the compatibility between PBT and TPU.With the increase of MDI contents,the tensile strength of PBT/TPU blends increases,while the elongation at break and notched impact strength of the blends first increase and then decrease.When the mass fraction of MDI is 1.0%,the elongation at break and notched impact strength of the blends reach 304%and 31.0kJ/m^(2),respectively,which are 591%and 308%higher than the blend without MDI.The addition of MDI can decrease the crystallinity of PBT/TPU blends,but does not change their crystal structures.