高分子凝胶体积相变中的氢键作用

The role of hydrogen bonding in the volume phase transitions of polymer gels

我们把关联模型(association models)推广应用到高分子凝胶体系,研究高分子与溶剂分子间的氢键和溶剂分子与溶剂分子间的氢键在高分子凝胶体积相变中的作用.首先通过分析凝胶体积分数与温度的关系发现,由于两种氢键作用,随着温度变化高分子凝胶出现连续、不连续体积相变,结果表明在体积相变过程中两种氢键都起着重要作用.其次,对不同氢键分数条件下的旋节线的研究发现,对于高分子凝胶体积相变中出现的UCST和LCST(上临界共溶温度和下临界共溶温度)现象也是由于高分子与溶剂分子间氢键和溶剂分子与溶剂分子间氢键共同作用的结果.

We presented a theory based on the association models to study the volume phase transitions in hydro-gen bonded polymer gels .Our theory model includes the considerations of polymer -solvent and solvent -solvent molecules hydrogen bonds .On the basis of the theory approach , we investigated the polymer gels volume fraction as a function of temperature and spinodal curves .It is clearly indicated that the polymer gels present continuous and discontinuous volume phase transitions owing to two types of hydrogen bonds .The calculated spinodal curves also reveal that the presence of UCST and LCST （ upper and lower critical solution temperature ） is caused by both the polymer -solvent and solvent -solvent molecules hydrogen bonds .