单体浇铸聚酰胺6/Kevlar纤维复合材料制备的温度场分析

Temperature Field of Monomer Casting Polyamide 6/Kevlar Fiber Composites During Preparation Process

采用有限差分法,将聚合热和结晶潜热当作内部热源,对单体浇铸聚酰胺6/Kevlar纤维(KF)复合材料成型的聚合和结晶过程进行数值模拟。结果表明:模具温度为145～160℃时,结晶在很大程度上影响着单体浇铸聚酰胺6浇铸体系的温度变化,随着模具温度的升高,影响变小,当模具温度为175℃时,结晶对体系温度的影响可以忽略。随着纤维含量的增多,反应结束的最高温度降低。将模拟结果和实验结果进行比较,反应一开始,实验值远远滞后于模拟值,然后逐渐趋于一致,二者偏离的原因主要是己内酰胺活性料吸热慢、采用密度法测结晶度和实际纤维的分散不均造成的。

Numerical simulation of cast-forming process and crystallization of Kevlar fiber reinforced monomer casting polyamide 6 was performed, the polymerization and crystallization heat were taken as internal heat sources in the finite difference method. When the mold temperature was in the range between 145 ℃ and 160 ℃, crystallization was main issue influencing the system temperature. The highest temperature of reaction system reduced with increase of the fiber mass. Compared with the simulated results, the determined value was much lower at the beginning stage of reaction, and became agreed at later stages. The slow endothermic velocity, errors in crystallinity determination, and nonuniform dispersion of fibers may be responsible for the deviation in the early stage.