水分对预聚体结构及其聚氨酯性能的影响∗

摘要

以二异氰酸酯(MDI-50)和端羟基聚丁二烯(HTPB)为原料,合成聚氨酯预聚体(PPU),加入不同比例的水分反应制得含水PPU。研究了水分对PPU的结构及相关性能的影响。傅立叶转换红外线光谱( FTIR)结果表明,PPU中的氢键作用对水分较敏感,且随着含水量的增加,硬段间的氢键相互作用加强,羰基的氢键作用趋向于无序化。溶解率测试表明,水分会起到扩链和交联的作用,交联倾向于在扩链后期加剧。同时水含量的增加,使得聚氨酯材料的玻璃化转变温度提高,机械性能降低。%Polyurethane prepolymer(PPU)was polymerized using diisocyanate(MDI-50)and hydroxyl-termina-ted polybutadiene( HTPB) oligomer,then different content of water was added into PPU to study effect of water on the structure and properties of PPU by Fourier transformation infrared spectroscopy ( FTIR ) , differential scanning calorimetry( DSC) ,etc. The FTIR results showed that formation of hydrogen bonds was sensitive to water content, hydrogen-bonding interaction between the hard segment and the disordered hydrogen-bonded peak area increased with increasing water content. The dissolution rate results showed that water content decided the effect of chain ex-tension and crosslinking behavior. Crosslinking degree tended to increased in the late period of extended reaction. The glass transition temperature and mechanical properties of corresponding PU materials increased and decreased respectively with the increasing addition content of water.