基于链端体积分数的聚合物溶液理论

提出“链端体积分数”的概念以克服Flory-Huggins(FH)理论中的平均场假设.将聚合物多链体系看成一条“间隔连续链”,使一些热力学量写成路径积分的形式.在聚合物/溶剂体系中,保留了FH理论的无热熵假设,把总熵分为两部分,建立了一个新的聚合物溶液理论.计算了聚苯乙烯/环己烷体系的FH相互作用参数和相分离曲线,并与实验数据和FH理论作了比较,结果表明,我们的理论结果比FH的理论结果有了很大的改进.

Theory of Polymer Solutions Based on Volume Fraction at Chain-end

The concept of volume fraction at chain-end is presented to overcome the mean-field approximation in Flory-Huggins(FH) theory. With the concept of interval-continuous chain introduced to replace multi-chains mathematically, some thermodynamical quantities can be written in path integral method. The entropy of polymer/solvent system is divided into two parts. Based on the conditions metioned above and the approximation that the interaction energy doesn′t affect the entropy of the system, a new theory of polymer solutions is built. The calculated FH interaction parameter and the spinodal curves with different molecular weights of PS are all quite well consistent with the experimental data, and much better than those of FH theory.