摩擦材料用酚醛树脂改性研究进展

综述了近年来摩擦材料用酚醛树脂增韧、增强以及耐热改性的研究进展。分析比较了橡胶、植物油、无机纳米材料、纤维以及聚苯并噁嗪树脂等改性体系对酚醛树脂基摩擦材料性能的影响。纳米粉末橡胶可同时提高酚醛树脂的耐热性和韧性,弥补了传统橡胶改性的不足;植物油可提高酚醛树脂的韧性,但也会使其的耐热性下降;无机纳米粒子的团聚问题影响其改性效果;纤维对酚醛树脂有增强增韧作用外,还可以明显改善其摩擦性能;而天然纤维可再生、价廉,而且强度高,但作为摩擦材料增强体,其耐热性有待改善;新型热固性酚醛树脂固化温度较高,要取代传统酚醛树脂还须进一步深入研究。

Research Advances of Modification of Phenolic Resin Used for Friction Materials

Research progress in recent years on toughening, strengthening and enhancement of heat resistance of phenolic resin (PF) used for friction materials is summarized. A comparative analysis of the different types of modifiers including rubber, vegetable oil,inorganic nanoparticles and fibers is presented. Rubber nanopowder can simultaneously improve the heat resistance and toughness of PF,and thereby offsetting the deficiency of traditional rubber modifier. Vegetable oil can enhance the toughness of PF,but it also reduces the heat resistance of PF. Inorganic nanoparticles show an unsatisfactory modification effect because they are easy to aggregate in PF. Fiber can improve the friction performance obviously in addition to enhancing the toughness and strength of PF. Natural fiber is renewable,cheap and high-strength,but its heat resistance remains to be improved as a reinforcement of friction material. To replace the traditional phenolic resin,the novel thermoset phenolic resin requires further study owning to its high curing temperature.