酚醛树脂的耐冲击增韧改性及其固化动力学研究

Study on impact resistance and toughening modification of phenolic resin and its curing kinetics

选用聚乙烯醇缩丁醛(PVB)、核壳橡胶、丁腈橡胶及环氧树脂作为增韧剂,对酚醛树脂进行增韧改性;通过制备复合材料试板进行耐冲击性能评价,研究了不同增韧剂体系及增韧剂添加量对酚醛树脂增韧效果的影响;通过流变、DSC测试结合非等温动力学方法研究了增韧改性酚醛树脂的固化动力学;并通过SEM观察试板冲击后的断面形貌,对增韧机理进行了解释。结果表明:以PVB为增韧剂改性酚醛树脂的韧性效果提升最为显著,且PVB的加入不会对该酚醛树脂体系的固化动力学造成影响;PVB添加量为15%时,改性酚醛树脂复材试板的耐冲击性能达到最大值23.72 J,且通过SEM分析,增韧改性酚醛树脂中加入的PVB使树脂基体在受到外力冲击时呈现出较好的韧性断裂。

Phenolic resin was toughened by polyvinyl butyral(PVB), core-shell rubber, nithile rubber and epoxy resin in this paper. The influence of different toughening agent systems and addition amounts of toughening agents on the toughening effect of phenolic resin was studied by evaluating the impact resistance performance of composite test panels. The curing kinetics of the toughened modified phenolic resin was studied by rheology, DSC testing combined with non-isothermal kinetics. The cross-section morphology of the test plate after impact was observed by SEM, and the toughening mechanism was explained. The results show that the toughness effect of modified phenolic resin modified with PVB as a toughening agent is the most significant, and the addition of PVB will not affect the curing kinetics of the phenolic resin system. When the amount of PVB added is 15%, the impact resistance of the modified phenolic resin composite test board reaches the maximum value of 23.72 J. According to SEM analysis, the PVB added in the toughened modified phenolic resin makes the resin matrix exhibit better ductile fracture when impacted by an external force.