长纤维增强反应注射成型聚氨酯基复合材料固化动力学研究*

摘要

Polyurethane(PUR)/glass fiber (GF) composites were prepared by using long fiber reinforced reaction injection molding process. In order to optimize solidification process parameters of PUR/GF composites,the influence of GF on curing dynamics characteristic of PUR was researched by using differential scanning calorimetry (DSC). The curing apparent activation energy and reaction grade were calculated,and the curing reaction equation was founded. The results show that the sensitivity of curing properties of the polyurethane to heating rate is reduced with the addition of glass fiber,the apparent activation energy and frequency factor of PUR/GF composites increase significantly,the reaction grade is from 0.7805 to 0.5299. The curing reaction heat temperature region widens,the curing reaction heat reduces significantly,curing onset temperature changes little,and curing peak temperature and curing termination temperature increase.%　　采用长纤维增强反应注射成型工艺制备了聚氨酯(PUR)／玻璃纤维(GF)复合材料，为了优化PUR／GF复合材料的固化工艺，运用DSC仪研究了GF对PUR固化动力学特性的影响，计算了PUR／GF复合材料的固化表观活化能和反应级数，并建立了相应的固化反应动力学方程。结果表明，随着GF的加入，PUR的固化特性对升温的敏感性降低，与纯PUR的表观活化能和指前因子相比，加入GF后其值有较大幅度增加，反应级数由0.7805变为0.5299。GF的加入，使PUR／GF复合材料的固化反应热温度区域变宽，反应热明显减少，固化起始温度变化不大，固化峰值温度和固化终止温度有所升高。