极性单体阴离子型聚合反应产物的分子量分布

关于任意官能度多官能团引发剂瞬时引发并有单体链终止的阴离子型聚合反应体系,本工作通过非稳态动力学分析,求得了分子量分布函数和平均聚合度的一般表示式,讨论了单体的最大消耗量和聚合物的官能度分布问题,建立了从反应的初始条件和单体转化率计算产物的各种分子参数的方法。上述理论结果适用于甲基丙烯酸甲酯等极性单体在极性溶剂中的阴离子型聚合反应。数值计算的结果表明:当引发剂的官能度为2时,除了少数例外,所得聚合物的分子量分布一般具有双峰。

MOLECULAR WEIGHT DISTRIBUTION OF POLYMERS GENERATED FROM ANIONIC POLYMERIZATION OF POLAR MONOMERS

For the anionic polymerization of polar monomer initiated by arbitrarily functional initiator, with instantaneous initiation and monomer termination, the expressions of molecular weight distribution, average degree of polymerization, functionality distribution and average functionality of the polymer formed have been derived by means of non-steady state method. The maximum amount of the monomer which will be consumed during the polymerization under consideration was discussed. A theoretical method has been established, with which the molecular weight distribution and the values of other molecular parameters can be calculated from the monomer conversion and initial conditions of the polymerization. It was shown that with a few exceptions, the theore-tical curves of molecular weight distribution resulted from numeric computation possess double peaks. Such a process is particularly true for the anionic polymerization of methyl methacrylate in polar solvents and at lower temperature.