聚偏氟乙烯/聚醚型热塑性聚氨酯弹性体共混物的相互作用及增容机理

采用流延成膜法制备了4种增容改性的聚偏氟乙烯(PVDF)与聚醚型热塑性聚氨酯弹性体(TPU)固体共混物(PVDF/TPU).结合分子动力学模拟研究了PVDF/TPU的相互作用,并探讨了其增容机理.研究结果表明,与PVDF/TPU-1,PVDF/TPU-2及PVDF/TPU-3相比,加入γ-缩水甘油醚氧丙基三甲氧基硅烷-端氨基丁腈橡胶(GPTMS-ATBN)后,PVDF/TPU-4的2个玻璃化转变温度(T_g)相互靠近,两相界面存在分布梯度,构成了双相连续的微观结构,表明GPTMS-ATBN增容PVDF/TPU共混物具有显著效果.同时,PVDF/TPU-4的共混结合能大幅减小,二面角扭转能、键角弯转能等明显增大,表明PVDF及TPU与GPTMS-ATBN之间发生相互作用.傅里叶红外光谱(FTIR)及X射线光电子能谱(XPS)证实了GPTMS-ATBN增容PVDF/TPU的机理为GPTMS-ATBN中ATBN链段与PVDF彼此缠绕,相互混溶,而水解后两端GPTMS中大量羟基与TPU分子链中氨基甲酸酯键及醚键相互吸附,从而生成了氢键.

Interfacial Interaction and Compatibilizing Mechanism of PVDF/TPU Blends

It is supposed that the adding of compatibilizer can play an important role on the compatibility of composite systems.In order to study on the effect of compatibilizerγ-glycidoxypropyltrimethoxysilane (GPTMS), amine-terminated butadiene acrylonitrile rubber(ATBN) and γ-glycidoxypropyltrimethoxysilane- amine-terminated butadiene acrylonitrile rubber(GPTMS-ATBN)] on the compatibility of poly(ethylene fluoride)(PVDF) and thermoplastic polyurethane(TPU), compatibilizer modified PVDF/TPU solid blends were prepared by compatibilizer combined with PVDF/TPU as matrix by solution casting, the interactions of PVDF/TPU blends were investigated by molecular simulation.Besides, the mechanism of compatibilization of the blends was deeply discussed by Fourier transform infrared spectroscopy(FTIR) and X-ray photoelectron spectroscopy(XPS).The results showed that compared with PVDF/TPU-1, PVDF/TPU-2 and PVDF/TPU-3, the molecular interactions existed between functional groups in PVDF/TPU-4 blends which were explained by the two temperature of glass transition(Tg) of PVDF/TPU-4 moved toward each other in DSC, distribution gra- dient existed in the interface of the two phases in the blends and a continuous two-phase microstructure was constituted after adding GPTMS-ATBN.All of these results displayed that GPTMS-ATBN played a significant effect on the compatibility of PVDF/TPU-4 blends.Moreover, the mixing energy of PVDF/TPU/-4 blends was significantly lower.Meanwhile, the values of bond energy, dihedral energy, angle energy and Vdw energy of the PVDF/TPU-4 blends were greater than the corresponding values of the others.It presented that molecular interactions were formed in PVDF, TPU and GPTMS-ATBN.The molecular simulation results were in agreement with the experimental results.Furthermore, based on FTIR and XPS, the compatibilizing mechanism of GPTMS-ATBN for PVDF/TPU was that the interwinding existed between the chain of ATBN and PVDF.In addition, the hydrogen bonding interactions displayed between the hydroxyl groups in the chain of hydrolytic GPTMS and the ether groups in TPU.The same intermolecular interactions produced between the hydroxyl groups and amino formic acid ester groups of GPTMS and TPU.