丁羟聚氨酯的结构、形态与性能关系的研究

STRUCTURE,MORPHOLOGY AND PROPERTIES OF POLYBUTADIENE POLYURETHANES

以一步法合成了一系列不同组成、不同硬段含量的丁羟聚氨酯,并以红外光谱、偏光显微镜、DSC、X光衍射仪、Instron材料试验机等对所合成样品的结构、形态及性能进行了表征。结果表明,扩链剂、硬段含量对C=O的氢键化程度以及体系的相分离程度都有影响;丁羟聚氨酯的T(?)约为—75℃,比纯丁羟的T_8约高6℃,表明该材料具有较高的微相分离程度;WAXS、DSC表明在MDI-丁羟聚氨酯中有结晶存在。丁羟聚氨酯的拉伸强度和硬度都随硬段含量的提高而增大,但伸长率下降,MDI-丁羟聚氨酯的性能优于DTI丁羟聚氨酯。

A series of polybutadiene polyurethanes has been prepared by one step method with different hard segment content and different diisocyanates. The structure, morphology and mechnical properties of the above samples were characterised by wide angle X-ray diffraction, infrared spectrometer, electron microscopy, opitical microscopy and Instron material tester. The WAXD curves show that there is diffuse peak for every sample and there is a small peak at 23° (20) for each MD1 based polyurethane sample which with chain extender partly crystallined. The IR result shows that there is about 60-70% C = O group without extender and about 80-90% with extender samples hydrogen bonded. Opitical microscopy shows that the phase separetion degree of HTPBD based polyurethanes is very high. The phase separetion degree of MDI based PUs is higher than that of TD1 based PUs. In the film sample, there is crystalline structure. Mechnical properties show that the stength and the hardness of the samples increase with the hard segment content increase . The strength and hardness of MD1 based PUs are higher than that of TD1 based PUs with the same hard segment content.