耗散粒子動力學模擬雙嵌段共聚物共混單團鏈共聚物於不同狀態下之行為探討

Dissipative Particle Dynamics Simulation Study on Behaviors of Diblock Copolymer/Homopolymer Blends in Different States

梁育誠

指導教授 ： 張榮語

國立清華大學/工學院/化學工程學系/碩士(2014年)

https://doi.org/10.6843/NTHU.2014.00223

摘要

高分子共混為高分子材料研究中技術之一。本研究為利用耗散粒子動力學模擬方法，模擬雙嵌段共聚物共混單團鏈共聚物在的自組裝行為，在本文主要是模擬聚苯乙烯-聚乙烯吡咯烷酮(PS-PVP)摻混聚苯乙烯(PS)的情況。主要控制變因為添加的單團鏈共聚物鏈長和添加的單團鏈共聚物比例及系統的溫度。在恆溫恆體積下，了解其形態變化和在何種控制變因下會產生層板狀結構。並利用高分子性質如末端末端距離和接點距離來探討在不同情況下層板結構的差異性。
本論文結果顯示：在共混單團鏈共聚物後，在無因次系統溫度介於1.0至1.4、PS體積分率介於0.5至0.6，其最終平衡形態圖為層板結構。而在固定溫度下，加入短鏈的單團鏈共聚物結果顯示單團鏈共聚物分佈在嵌段和嵌段之間；而加入的為長鏈單團鏈共聚物，長鏈單團鏈共聚物則會較集中在層板中央。而在改變溫度情況下，在低溫時，中等長度的單團鏈共聚物分佈情形較和短鏈單團鏈共聚物相似；而高溫時，中等長度的單團鏈共聚物分佈情形則與長鏈單團鏈共聚物相似。

關鍵字

耗散粒子動力學 ； 高分子共混 ； 高分子形態學 ； 層板結構 ； 自組裝

並列摘要

Polymer blending is one of important technologies in polymer processing. In this work, we simulated the self-assembly of diblock copolymer Polystyrene-Polyvinylpyrrolidone (PS-PVP) and homo- Polystyrene (homo-PS) by dissipative particle dynamics (DPD) simulation method. The variables we changed are the chain length and volume fraction of added homopolymer, and the system temperature. In NVT ensemble, we investigated how morphology changing with different variables; and understood how lamellar structures formed with control variables. Finally, we used polymer properties such as end-to-end distance, junction point distance, and thickness of lamellar to discuss differences in different lamellar structures.
In this thesis, the results show: after blending diblock copolymer with homopolymer, while temperature ranging from 1.0 to 1.4 and the volume fraction of polymer A ranging from 0.5 to 0.6, the equilibrium morphology is lamellar structure. In fixed temperature, while blending short-chained homopolymer, it shows homopolymer would locate between blocks. When blending with long-chained homopolymer, the long-chained homopolymer would be at the central of lamellar. In the case of changing the temperature: at low temperature, the distribution of moderate-chained homopolymer is more similar to short-chained homopolymer; while at high temperature, the distribution of moderate-chained homopolymer is similar to long-chained homopolymer

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