环氧树脂在碳纤维表面的浸润行为

利用场发射环境扫描电境(FESEM)测定了室温下环氧树脂在单纤维表面的接触角,观测并计算了环氧树脂液滴在单根碳纤维表面的接触角随温度的变化,结果表明接触角随温度升高明显降低,说明升高温度有利于改善环氧树脂对碳纤维的浸润性能.用液滴形状分析仪(DSA)在垂直和平行于纤维排列方向上观测了不同温度下单向排列碳纤维集束表面环氧树脂的铺展过程,发现在不同方向上观测到的接触角差别较大,其中垂直于纤维排列方向上观测到的接触角随温度的变化与环氧树脂在单根碳纤维表面的接触角变化基本一致,说明环氧树脂在平行于纤维束方向的接触角真正代表其浸润性能.

WETTABILITY OF EPOXY RESIN ON CARBON FIBER

The micrographs of epoxy resin on single carbon fiber at room temperature and the temperature dependent contact angle on single carbon fiber were investigated using field environmental scanning electron microscope (FESEM).The results showed that the contact angle decreases significantly with increasing temperature.The advantage of this experimental approach was that can directly reflected the wettability of epoxy resin to fiber.But the experimental process was complicated,and there were many influence factors.The reason is that the wettability of epoxy resin on parallel sheet can be improved at higher temperatures.The spreading procedures for the epoxy resin droplet on carbon fiber cluster were observed by means of drop shape analysis system (DSA) in parallel and perpendicular directions of the aligned fibers.It was found that the temperature dependent contact angles were quite distinct from the different observed directions.Moreover,the contact angles observed perpendicular to the direction of fibers are consistent with the results on the single carbon fiber,which indicates that the wetting behavior of epoxy resin to the fiber in the direction parallel to the fiber cluster can truly represent the wettability.Then,the complicated method about single fiber of using FESEM to understand the wettability of epoxy resin to fiber could be replaced by using DSA.It should save much time and energy for the practical industry.