壳聚糖-氧化石墨烯/热塑性聚氨酯复合材料的原位溶液聚合及性能

In-situ solution polymerization and properties of chitosan-graphene oxide/thermoplastic polyurethane composites

为了制备高力学性能、阻隔性能和导热性能的热塑性聚氨酯(TPU)复合材料,采用改进的原位溶液聚合法,将壳聚糖改性的氧化石墨烯(CS-GO)与TPU预聚体接枝,再经扩链反应得到CS-GO/TPU复合材料。利用FTIR、XRD、FESEM对CS-GO进行表征,并采用万能试验机、氧气透过仪和导热仪对CS-GO/TPU复合材料的性能进行测试分析。结果表明:CS与GO之间存在氢键作用,CS-GO在TPU基体中的分散性优于GO。CS-GO的均匀分散有效阻隔了O2的渗透,提高了CS-GO/TPU复合材料的阻隔性能。CS-GO与TPU基体之间的相互作用有利于应力载荷的传递和导热网络的形成,与纯TPU相比,当CS-GO含量为1wt%时,CS-GO/TPU复合材料的拉伸强度和断裂伸长率分别提高了106.8%和111.2%,导热系数提高了1.55倍。

An improved in-situ solution polymerization method was used in order to prepare the thermoplastic polyurethane(TPU)composite with high mechanical properties,barrier properties and thermal conductivity.Graphene oxide modified by chitosan(CS-GO)was grafted onto TPU prepolymer,then CS-GO/TPU composite was synthesized by chain extension reaction.The microstructure of CS-GO was characterized by FTIR,XRD and FESEM.The properties of CS-GO/TPU composites were tested by universal testing machine,oxygen transmission instrument and thermal conductivity meter.The results show that there is a hydrogen bond between CS and GO,and the dispersibility of CS-GO in the TPU matrix is better than GO.The enhancement of barrier property of CS-GO/TPU composites is due to the uniform dispersion of CS-GO which can effectively block the penetration of oxygen.The interaction between CS-GO and TPU matrix has positive effect on the transmission of stress load and the formation of a thermally conductive network.Compared with the pristine TPU,when mass fraction of the CS-GO is 1 wt%,the tensile strength and elongation at break of CS-GO/TPU composites are increased by 106.8%and 111.2%,respectively;the thermal conductivity is 1.55 times higher than the pristine TPU.