引用本文:
【打印本页】   【HTML】   【下载PDF全文】   View/Add Comment  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览 1076次   下载 1303 本文二维码信息
码上扫一扫!
分享到: 微信 更多
Statistical Theory of the Stable and Metastable Transitions for Crystallization and Fusion of Homopolymers
Song Mingshi*,Chen Jianquan,Hu Guixian,Zhao Bin,Li Xiaoyu*
Author NameAffiliationE-mail
Song Mingshi* The Key Laboratory of Science and Technology of Controlled Chemical Reaction, Ministry of Education, School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 songmingshi@mail.buct.edu.cn 
Chen Jianquan The Key Laboratory of Science and Technology of Controlled Chemical Reaction, Ministry of Education, School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029  
Hu Guixian The Key Laboratory of Science and Technology of Controlled Chemical Reaction, Ministry of Education, School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029  
Zhao Bin The Key Laboratory of Science and Technology of Controlled Chemical Reaction, Ministry of Education, School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029  
Li Xiaoyu* The Key Laboratory of Science and Technology of Controlled Chemical Reaction, Ministry of Education, School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029  
Abstract:
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(△Gnf and △Gcv) and in the rate of (△Gnf/f) and (△Gcv/v) on their sizes (f and v), so that three regions (unstable, metastable and stable)are divided.
Key words:  Dynamics of crystallizations, Evalution equation for nucleation, Evalution equation for growth, Stability and metastability, Molecular segregation
FundProject:国家重点基础研究专项基金资助项目(G1999064809).
均聚物结晶与熔融化的稳态和亚稳态转变统计理论
宋名实*,陈建全,胡桂贤,赵彬,李效玉
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
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  稳态和亚稳态
DOI:10.1088/1674-0068/16/4/270-288
分类号: