聚苯乙烯的材料性質受到其主鏈與苯環運動的影響，分子內主鏈與苯環的交互作用支配著結構的鬆弛。已知剪切流動會影響直練分子的構型和原子分布，然而剪切所導致的鏈段鬆弛與苯環轉動變化尚未被探索完全。在本研究的第一部份，分子動力學模擬被用來探討主鏈與鏈段鬆弛和溫度、壓力以及剪切速率的相依性。結果顯示主鏈和鏈段的鬆弛具有相似的溫度、壓力和剪切速率相依性，然而在相依的程度上卻有所不同。在本研究的第二部份，非平衡分子動力學模擬被用來討論剪切流場對苯環轉動的效應。結果顯示當剪切速率小於1010s-1時，轉動自由能能障會趨於一個定值，剪切速率大於1010.5s-1時則隨著剪切速率增加而下降。值得注意的是，剪切流動會抑制苯環內各種鍵結的振動同時增加不同分子之間粒子對的距離。如此一來苯環發生轉動所需要的空穴體積變小，而空穴可佔有的體積變大；因此在剪切速率大於1010.5s-1時，需要靠主鏈運動來增加的體積下降，使得轉動自由能能障下降。

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