聚硅氧烷聚脲多嵌段共聚物中氢键的研究

采用多种手段研究了聚硅氧烷与聚脲嵌段共聚物中所存在的各类氢键．特别探讨在聚硅氧烷软段中引入极性氰丙基对体系成氢键能力的影响和两相间相互作用力的情况结果表明，在软段分子中引入极性氰丙基有利于增加聚硅氧烷分子与聚脲链段的相互作用，这一相间作用力使两相间界面层厚度随着硬段分子量的增加而加宽，并发现在聚硅氧烷聚脲嵌段共聚物中硬段的聚集形态随溶液浓度改变变化不大，其中氢键随着温度升高而下降．

STUDIES ON THE HYDROGEN-BOND IN THE POLYSILOXANE-POLYUREA BLOCK COPOLYMERS

series of polyurea block copolymers based on either aminopropyl terminated cyano-containing polysiloxane or polydimethylsiloxane soft segments was synthesized. The hard segments consisted of 4,4'-methylenediphenylene diisocyanate chain extended with ethylenediaAnne.The hydrogen bond and the morphology of these block copolymers were studied by FT-IR,NMR and DMA. These materials exhibited microphase separation of the hard and soft segments, and the microdomains may change greatly in different systems due to the difference of the hydrogen-bond in these block copolymers. The hydrogen-bond in the cyano-containing polysiloxane-polyurea block copolymers was not only in the hard segment domains but also in the interphase between the soft and hard segments; attaching polar cyano side groups along the polysiloxane chains promoted phase dnaing in comparison with polydimethylsiloxane - based polyurethanes. The hydrogen- bond between the soft and the hard segments increased with the increase of the thickness of the interphase. The observation also showed that the hydrogen-bond in the block copolymers was affected by the concentration and the temperature of the solution.