【摘要】 <正> 在高分子化学基础理论中,自由基聚合部分占有很大的比重。这是因为自由基聚合研究得较早,其理论较为成熟;其次是大部分高分子材料的生产属于自由基聚合范畴。但是在通用教科书中,有关自由基的浓度和寿命与动力学的关系论述较少,而定量处理几乎未见报导。因此,学生普遍感到对自由基聚合动力学难于理解。笔者认为“活性种”是自由基聚合动力学的核心问题,有必要作深入的分析。在教学实践中,学生普遍反映笔者对自由基聚合中活性种的剖析容易抓住本质,便于理解和记忆。本文重点论述自由基的浓度和寿命与动力学的关系。更多还原

【Abstract】 The concentration of the reactive species and lifetime of radicals in free radical polymerization hasnt been well investigated in the current text books,so that students often feel much difficult to understand the kinetics of free radical polymerization.In this paper,the relations between the concentration of radicals,lifetime of radicals and other kinetic parameters are analyzed.The result shows that,when polymerization is initiated by usual free radical initiators,the concentration of radicals increases,and the lifetime dicreases with the rise of the temperature,while the rate of polymerization and the rate of termination both increase with raising the temperature,but extent of the increasing of the termination rate is much bigger than of the polymerization rate.The rise of termination rate is essentially effected by the change of the square value of concentration of the radical rising with the temperature.Though the rate constant of the prapaga-tion rises with the temperature,the lifetime of free radical shores rapidly,so that the member-average degree of polymerization decreases very fast.更多还原