均聚物结晶与熔融化的稳态和亚稳态转变统计理论  

Statistical Theory of the Stable and Metastable Transitions for Crystallization and Fusion of Homopolymers

作　　者：宋名实[1] 陈建全[1] 胡桂贤[1] 赵彬[1] 李效玉[1] 

机构地区：[1]北京化工大学可控化学反应科学与技术基础教育部重点实验室,材料科学与其工程学院北京100029

出　　处：《Chinese Journal of Chemical Physics》2003年第4期270-288,共19页化学物理学报（英文）

基　　金：国家重点基础研究专项基金资助项目 (G19990 6 4 80 9)

摘　　要：基于多重微晶网络结构模型和分子分凝机制建立了高分子晶体的微晶核 和微晶粒 高分子链组模型 ,推导出了平衡态下高分子预结晶动力学方程 ,计算出了平衡态下不同尺寸微晶核 和微晶粒 高分子链组的几率分布函数 .建立了非稳态下不同尺寸的微晶核 高分子链组的成核演化方程和微晶粒 高分子链组的增长演化方程 ,求解一般状态下的两个演化方程后 ,得到了不同时间和不同尺寸的微晶核 和微晶粒 高分子链组的一般密度分布函数 .最后根据成核自由能和增长自由能对晶核和晶粒的尺寸大小的依赖性 ,提出了微晶核 高分子链组和微晶粒 高分子链组存在稳定性的热力学条件和动力学条件 ,成功地表征为三个特征区 (稳态、亚稳态和非稳态 )Based on the structural model of multiple crystal networks and the mechanisms of crystallization by molecular segregation of stems, the process of crystallization for homopolymers was divided into three kinds of correlative and separatory steps, namely, the process of precrystallization under the equilibrium state, the evalution process of dynamics for nucleation in the unsteady state and the evalution process of dynamics for growth in the dynamic state. The kinetic equation of precrystallization under the equilibrium state, the evalution equation of dynamics for the nucleation of micro-nucleus-constituent chain and the growth of micro-crystal-constituent chains under the unequilibrium state were established. The probability distribution functions for the micro-nucleus-constituent chains and the micro-crystal-constituent chains by extending and folding chains with different sizes and the end-to-end vectors at different times(t) were obtained, respectively, from the solutions of the evalution equations of dynamics for nucleation and growth. A new method of establishing the criterion for the stability and metastability of micro-nucleus and micro-crystal-constituent chains was proposed. It is based on the dependence of change in the free energy for the formation of micro-nucleus and micro-crystal-constituent chains ( DeltaG(nf) and DeltaG(cv)) and in the rate of ( partial derivative DeltaG(nf)/ partial derivativef) and ( partial derivative DeltaG(cv)/ partial derivativev) on their sizes (f and v), so that three regions (unstable, metastable and stable) are divided.

关 键 词：分子分凝折叠链晶 结晶动力学 成核演化方程 增长演化方程 稳态 亚稳态 均聚物结晶 

分 类 号：O781[理学—晶体学]