摘要
基于COMPASS力场和三维周期性边界建立全同立构聚丙烯(iPP)与金属镍(Ni)模仁的界面模型。采用分子动力学法观察注塑成型过程中塑件表皮层在不同模温下形成的动态演变,通过分析体系的密度分布,均方位移和界面能以及运动规律等构象统计深入探究表皮层形成的分子机制。结果表明,分子链热运动同时受能量阈值和时间阈值限制;高模温既能降低两相间的界面能,又能降低熔体的黏度,有利于熔体的流动充填;表皮层纳米型腔的填充主要在保压阶段,且最高填充率能达到95.4%;脱模后塑件表皮层虽能保持整体的大致模样,但有一定程度的形状变形。
The interface model between isotactic polypropylene （iPP） and nickel （Ni） mold was constructed, based on the COMPASS force field and 3D periodic boundary. Morphology evolutionary process of the epidermis was investigated by molecular dynamics in the injection process with different mold temperature. Furthermore, the molecular mechanism of epidermis formation was analyzed by the configurational statistics, such as the density distribution, mean square displacement, interfacial energy and characteristics of motion. The results show that the thermal motion of molecular chains is affected by both energy thresholds and time threshold. High mold temperature can reduce the interracial energy between polymer and mold, and the viscosity of polymer melt, which is advantageous to the melt filling. The filling process of the nanometer cavity mainly in the packing stage, and the highest filling rate is about 95.4 %. The epidermis can maintain overall appearance except for a certain degree of shape deformation after de-molding.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2017年第12期92-98,共7页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(51365038)
江西省自然科学基金资助项目(20161BAB206123)
江西省高校科技落地计划项目(KJLD12058)
关键词
注塑成型
表皮层
充填机理
分子模拟
injection molding
epidermis
filling mechanism
molecular simulation
