【摘要】 采用一步简单的有机反应合成液晶中间体4,4–双(6–羟基己氧基)联苯(BP6),并将其与六亚甲基二异氰酸酯和聚四氢呋喃二醇预聚,最后将预聚体与1,1,1–三(羟甲基)丙烷发生交联反应,制备了一种热固性液晶聚氨酯弹性体(LCPUR)。通过傅里叶变换红外光谱、X射线衍射、X射线小角散射等手段对热固性LCPUR的结构进行表征,随后分别用万能试验机和热重分析仪对其力学性能和热稳定性进行表征。结果表明,热固性LCPUR已经成功合成。通过改变液晶相的含量可以调控聚氨酯(PUR)的微相分离程度和力学性能。当液晶中间体BP6的添加量为20%时,热固性LCPUR的力学性能最好,断裂强度高达30.06 MPa,是纯PUR的2.67倍;断裂伸长率为1685%,是纯PUR的1.58倍。过量的BP6虽然会导致力学性能下降,但会提高LCPUR材料的拉伸弹性模量。联苯型液晶中间体的引入是自增强PUR的有效手段。更多还原

【Abstract】 A facile organic reaction is used to synthesize the liquid crystal intermediate 4，4-bis(6-hydroxyhexyloxy)biphenyl (BP6).The thermosetting liquid crystal polyurethane elastomers(LCPUR) were prepared with hexamethylene diisocyanate，polytetrahydrofuran glycol and BP6，finally cross-linked by 1，1，1-tris (hydroxymethyl propane).The structures of LCPUR were characterized by Fourier transform infrared spectroscopy，X-ray diffraction，X-ray small-angle scattering，and then the mechanical properties and thermal stability of LCPUR were characterized by a universal testing machine and thermogravimetric analyzer.The results show that LCPUR have been successfully synthesized.The micro phase separation and mechanical properties of polyurethanes(PUR) can be adjusted by changing the content of BP6.When the addition amount of the liquid crystal intermediate BP6 is 20%，the mechanical property of LCPUR is the maximum.The breaking strength is as high as 30.06 MPa，which is 2.67 times that of PUR and the breaking elongation is 1685%，which is 1.58 times that of PUR.Excessive BP6 cause a decrease in mechanical properties，but the tensile elastic modulus of LCPUR material is still increased.It is an effective way to strengthen PUR in situ by introduction of biphenyl liquid crystal intermediates.更多还原