环境老化对CF/VE拉挤复合材料动态力学性能的影响

Effect of Environmental Ageing on Dynamic Mechanical Properties of Pultruded Carbon Fiber/Vinyl Ester Resin Composites

采用动态力学热分析(DMTA),研究了炭纤维/乙烯基酯树脂(CF/VE)拉挤复合材料在65℃蒸馏水和3%NaCl、5%H2SO4及10%NaOH水溶液中浸泡不同时间及重新干燥后,其动态力学损耗(tanδ)和玻璃化转变温度(Tg)的变化。结果表明,随浸泡时间的延长,四种介质中复合材料的力学损耗均有不同幅度的递增,其中,以NaOH水溶液中的增加幅度最大,而且出现了tanδ的分峰现象;Tg在浸泡初期逐渐下降,浸泡后期,除在NaOH水溶液中出现短暂的平稳又继续下降外,其余三种介质中均趋于一稳定值。重新干燥后,NaOH水溶液中,tanδ的分峰现象消失,但因水解脆化作用导致复合材料的Tg比浸泡前偏高,其余三种介质中,不存在水解反应,Tg均与浸泡前的相同。

The changes in loss factor （tanδ） and the glass transition temperature （Tg） of pultruded carbon fiber/vinyl ester （CF/VE） resin composites were studied by dynamical mechanical thermal analysis （DMTA） during their immersion in distilled water, 3%NaCl aqueous solution, 5%H2SO4 aqueous solution and 10%NaOH aqueous solution at 65℃. The results show that the loss factor of the composites in the four media increases at a various degree with immersion time, there being the largest degree of increase and a split in rand in 10%NaOH aqueous solution. Tg of the composites decreases at a various degree in the four media at the early immersion stage, then tends to a constant except for decreasing with the farther prolongation of immersion time in 10%NaOH aqueous solution. When re-dried, Tg of the composites in distilled water, 3%NaCl and 5%H2SO4 aqueous solutions nearly recovers to the same as that before immersion, but is higher in 10%NaOH aqueous solution due to the hydrolysis.