半晶态与非晶态聚合物的微观变形机理  

Microscopic Deformation Mechanisms of Semicrystalline and Amorphous Polymer

作　　者：颜世铛[1,2] 段芳莉[1] 

机构地区：[1]重庆大学机械传动国家重点实验室,重庆400030 [2]郑州机械研究所,河南郑州450000

出　　处：《高分子材料科学与工程》2014年第3期100-104,共5页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(50875271);机械传动国家重点实验室科研业务费(SKLMT-ZZKT-2012 MS 18);中央高校基本科研业务费资助(CDJZR12 24 8801)

摘　　要：采用粗粒化聚乙烯醇模型,应用大规模分子动力学分别模拟半晶态和非晶态聚合物的单轴拉伸变形,探究两者潜在的变形机理。半晶态聚合物的应变软化过程主要发生在晶区,而应变强化过程主要体现在非晶区。晶区在屈服点发生滑移,初始滑移形成使晶区变化需要的拉伸力变小,而发生应变软化。随着应变的增大,各分子链段协同作用使二者分子链的解缠结达到最大,取向趋向于拉伸方向,从而使拉伸应力增大发生应变强化。重要的是还得到半晶态聚合物中的非晶区,表现出与非晶态聚合物相似的应力-应变行为。Molecular dynamics simulation in coarse grained model of polyvinyl alcohol was used to study the uniaxial tensile deformation and the potential deformation mechanisms of semicrystalline and amorphous polymer. The strain softening of semi crystalline polymer occurs mainly in the crystalline region, while the strain hardening is mainly reflected in the amorphous region. Crystalline slippage occurs at the yield point, the force of crystalline deformation becomes smaller after the formation of the initial slip, so that the occurrence of strain softening. As the strain increases, the maximum disentanglement and molecular chain orientation tend to the stretching direction though the synergistic effect of each molecular chain segment, which requires more stress, then the strain hardening occurs. Amorphous region of semicrystalline polymer shows the similar stress strain behavior with amorphous polymers.

关 键 词：半晶态聚合物 非晶态聚合物 分子动力学模拟 粗粒化模型 变形机理 

分 类 号：O631.13[理学—高分子化学]