聚合物屈服中结构变化的计算机模拟

用分子模拟方法对近来关于在屈服中是否存在结构改变的问题进行了考察.结果表明,在屈服附近键长与键角没有明显的变化,而且分子间相互作用主宰着屈服过程.研究发现,屈服过程中有一个“原子跳跃”的结构转变现象,即部分原子的位移超出所有原子平均位移的10倍以上.另外,高分子链间堆砌的复杂性引起屈服点附近的多重原子跳跃发生.用该结果可以较合理地解释高分子有一个宽的屈服峰.

Computer Simulation on the Change of Polymer Structure During Yielding

Whether there is a structural change during yielding was studied by molecular modeling. The results indicate that bond length and bond angle change little while intermolecular interaction dominates the yielding process just as other studies showed. But a structural transition phenomenon called "atom jump" was found during the yielding. The displacements of some atoms exceed ten times of the average displacement of all atoms. In addition, the complexity of polymer chain packing induces the multiple atomic jumps around the yielding point, which can be used to explain properly why polymers have a broad yielding peak.