摘要
采用固体高分辨１３Ｃ核磁共振谱以及溶液碳谱、氢谱的方法对以聚四氢呋喃（ＰＴＭＯ）为软段、４，４’－二苯基甲烷二异氰酸酯（ＭＤＩ）为硬段、４，４’－二羟已氧基联苯（ＨＢ６）为扩链剂的液晶型聚氨酯弹性体的相态结构、分子运动、氢键相互作用等问题进行了研究。探讨了样品的化学结构与上述问题间的关系。
he 13C CP/MAS,PST/MAS and DD/MAS NMR experiments were carried out on a mainchain liquid-crystalline polyurethane elastomer based on poly(tetramethylene oxid)(PTMO),4,4'-diphenylmethane diisocyanate(MDI)and 4,4'-bishydroxyhexyloxybiphenyl(HB6).The HB6 segment which serves as chain extender in the sample was found to be well crystallized,whereas the hard segment MDI was not because of the great content of graft structure in the MDI segment(Scheme2).The mobility of MDI segment was found to be higher than that of the HB6 segment in both MHz and low frequency regions.Two carbonyl peaks were observed in the 13C CP/MAS spectrum and were assigned to hydrogen-bonded and free carbonyl groups.The relative content of free carbonyl groups is higher than that of the hydrogen-bonded ones.A small peak at about 64.80 ppm in both 13C high-resolution spectrum in DMF-d7 and 13C CP/MAS spectrum is assigned to the methylene carbon that locates at the chain end of the PTMO soft segment.
出处
《功能高分子学报》
CAS
CSCD
1995年第4期400-408,共9页
Journal of Functional Polymers
基金
国家教委留学归国人员科研资助
关键词
液晶型
聚氨酯弹性体
核磁共振
Main-Chain liquid crystalline polyurethane elastomer,Solid-State high-resolution 13C NMR
