CF/PU复合材料的固化过程及其动态力学性能

CURING PROCESS AND DYNAMIC MECHANICAL PROPERTIES OF CF/PU COMPOSITE

本工作借助于TBA、DMS、热失重曲线测试等方法,对CF/PU复合材料的固化过程及影响其动态力学性能的因素进行了进一步研究。结果表明,无论在室温还是在其它温度下,CF-1/PU的固化都比CF-3/PU的固化快。PU在已完全固化的CF-3/PU上固化比在CF-3上固化快的现象进一步证实CF表面上的OH和COOH基团参与了PU固化反应。本实验条件下,室温固化和143℃固化的CF/PU样品在升温至200℃左右都发生了后固化反应,PU的热失重曲线在230℃之后开始急剧下降,CF/PU不适宜在200℃固化。CF/PU体系的动态力学性能受固化温度的影响比PU体系更显著,表明基体和纤维之间的界面效应与固化温度有关。所研究的CF/PU体系较符合模型:界面层网络最致密,接近界面层的基体网络较疏松,距界面层较远处基体的交联密度介于前两者之间。

Curing process of CF/PU composite and the factors which influence the dynamic mechanical properties of CF/PU system were further investigated by means of TBA,DMS and Thermogravimetric Analyzer. The experiments showed that the curing rate of CF-l/PU system was faster than that of CF-3/PU system under various curing temperature. The phenomena that the curing rate of PU on CF-3/PU which has completely cured is faster than on CF-3 braids, verify that the OH and COOH groups on the surface of CF took place the PU curing reaction.The fact that the influence of curing temperature on the dynamic mechanical properties of CF/PU system was more apparent than on that of PU system, demonstrated that the interfacial effect between PU and CF connected with the curing temperature. The CF/PU system studied accord with the model, in which crosslinking density at interfacial layer is the highest, the crosslinking density of PU being close to the interfacial layer is the lowest, and the crosslinking density of PU far from the interfacial layer lies between them,