主链含四重氢键基元聚氨酯的合成与性能

SYNTHESIS AND PERFORMANCE OF POLYURETHANE WITH QUADRUPLE HYDROGEN BOND UNITS

合成了一种新型含有UPy(2-ureido-4[1H]-pyrimidone)基团的二羟基化合物,以此二羟基化合物作扩链剂,通过与聚氨酯预聚体进行的扩链反应,制备了一系列主链含UPy的聚氨酯(PU-UPy).傅里叶红外光谱(FTIR)、氢核磁共振(1H-NMR)等测试结果表明,在聚氨酯主链中确实含有UPy链段.同时,热性能及力学性能测试表明,聚氨酯中的UPy二聚体会集聚而形成微晶,熔点在60℃附近.在聚氨酯主链中引入UPy,能大幅提高聚氨酯的力学性能,调整软段的分子量,以及在主链中UPy含量可改变聚氨酯弹性体的断裂伸长率和抗张强度.

A new kind of supramolecular polymer can be obtained through hydrogen bond interactions of UPy（2-ureido-4-pyrimidone） units.So it is a new method of polymer modification.Inspired by this,a new kind of polyurethane with UPy units in the main chain was designed.A novel polyurethane chain extender containing UPy units was synthesized through five steps.UPy units were introduced into the main chain of the polyurethane through reacting OH groups with the NCO groups in the prepolymer.The structure was characterized by FTIR and 1H-NMR.The thermal testing results showed that the UPy units aggregated to form microcrystals which melted around 60℃ in the polyurethane.The polyurethane with UPy units in the main chain showed greatly improved mechanical performances compared to the non-UPy counterpart in the tensile testing.The breaking strength was up to 28.6,17.3,15.5,14.9 MPa by using PTMG650,1000,1400,2000 as the soft segment.UPy content in the PU can be adjusted through changing the molecular weight of the soft segment to get PU elastomers with proper performance.