立體正規性對聚丙烯在溶液中的影響:分子動力學模擬

Effect of Tacticity of Polypropylene in Solution: Molecular Dynamics Simulation

洪玉蕙(Yu-Hui Hung)

指導教授 ： 張榮語

國立清華大學/工學院/化學工程學系/碩士(2008年)

摘要

二十一世紀是個奈米科技的時代，而奈米科技是由技術、科學跟材料所結合的，材料經由加工技術製成產品，為了發揮高分子材料的特性，了解材料的物理性質是非常重要的，而且在現在的加工技術中多把高分子材料加入溶劑形成高分子溶液，進而做成薄膜，在奈米尺度下具有很重要的應用前景及具有極大的市場與價值。
利用分子動力學模擬研究立體正規性(tacticity)，了解接枝甲基在空間上排列形式不同的立體化學性質對聚丙烯在溶液中有什麼不一樣的行為，諸如聚丙烯高分子鏈及構型變化作分析及探討，同時也針對高分子在溶液中的濃度及鏈長變化作討論，聚丙烯是個應用廣泛的乙烯基聚合體，因為接枝甲基不同的排列方式而有奇妙的物理性質，本研究將先跟文獻作比較，以確定系統材料的正確性，再將不同立體結構的聚丙烯跟非極性溶劑作混合製成聚丙烯溶液，以徑向分布(radial distribution function)、末端末端距離(end to end distance)、旋轉半徑(radius of gyration)等作為比較。

關鍵字

分子動力學模擬 ； 聚丙烯 ； 立體正規性

並列摘要

The 21st century is an era of Nanotechnology which is combined with technology, science and material. And material is manufactured into the products via the process technology. It is important to understand the physical properties of the material in order to benefit form the characteristic of polymer. Adding polymer into solvent to form solution among the process of technology is general now, and further make into the membrane. It is very important for prospect of application and has great market and value under nano scales.
In the work, results of different tacticity for polypropylene are present via molecular dynamics simulations, based on understanding the differences of three-dimensional chemical properties that the pendent (C-CH3) methyl groups for polypropylene arrange on the space differently. Such as the conformation of chains for polypropylene are analyzed and discussed. Effects of the concentration of solutions and chain length are also investigated. Polypropylene is a vinyl polymer with a wide variety of applications that there is a wonderful physical property because of pendent (C-CH3) methyl groups arranged on the space differently.
This research will make comparisons with paper first, in order to ensure the validity of programs for the systems and materials. Then different structures of polypropylene mixing with non-polarity solvent are compared via the radial distribution functions, end to end distance, and radius of gyration, etc.

並列關鍵字

molecular dynamics simulations ； polypropylene ； tacticity

參考文獻

[17]T.A.Kavassalis,P.R.Sundararajan,''A Molecular Dynamics

Introduction to polymers''(1991)

[12]A.Rahman,'' Correlation in the Motion of Atoms in

,(1988)

Study of Polyethylene Crystallization''