中文摘要：

采用粗粒化聚乙烯醇模型,应用分子动力学方法模拟熔融态聚合物经过缓慢冷却、局部结晶形成半晶态聚合物的过程.静态结构因子的演变显示出在结晶初期小角散射强度的增大先于布拉格峰的出现,这与小角/大角X射线散射实验现象相一致.模拟得到的半晶态聚合物呈现为折叠链构成的晶区与非晶区交杂在一起的结构形态,与缨状微束结构模型相一致.研究发现在不同的冷却阶段具有不同的有序结构形成机制.从结晶温度到玻璃化温度的凝固过程中,存在分子链的伸展和伸直分子链之间平行排列两种形式的结构转变;而在玻璃化温度之后,材料的活性只允许调整伸直分子链之间的相对排列位置.

英文摘要：

Molecular dynamics simulation in coarse-grained model of polyvinyl alcohol is made to get semicrystalline polymer from a molten state with slow cooling and partial crystallization. Evolution of static structure factor shows that intensity increasing in small- angle scattering appears before the Bragg peak in early crystallization, which is consistent with experimental observations with small/ wide angle X-ray scattering. Simulated semicrystalline polymer shows a structure resembling Ying-shaped micro-beam model. Different cooling stages have different formation mechanisms with ordered structures. From crystallization to glass temperature in solidification process, stretching of molecular chain and arranging in parallel between straight molecular chains exist. Adjustment of straight chains in relative positions is only allowed by material activate.