超细聚四氟乙烯微粉改性聚甲醛复合材料的制备及性能

Preparation and Properties of Superfine Polytetrafluoroethylene Powder Modified Polyformaldehyde Composites

利用聚四氟乙烯(PTFE)的耐磨性与自润滑性能,采用超细PTFE微粉与聚甲醛(POM)制备PTFE-POM耐磨复合材料,研究了PTFE微粉的含量对复合材料力学性能、加工流动性能、耐磨性能的影响,并通过扫描电镜测试分析了产生上述现象的原因。结果表明,随着复合材料PTFE含量的增加,其力学性能出现一定程度的下降,但加工流动性和耐磨性能均有显著的提升。扫描电镜测试结果表明,PTFE微粉与POM部分相容,导致其力学性能较纯POM下降;由于PTFE微粉的隔离效应,使得复合材料加工流动性能显著改善;由于注塑成型过程中PTFE部分向材料表面迁移,使得复合材料耐磨性能得到显著提高。所制备的PTFE-POM复合材料其成本与杜邦已商品化的AF500相当,但性能尤其是耐磨性显著优于AF500,可代替AF500作为工程塑料耐磨结构件使用。

Due to wear resistance and self-lubricating properties of PTFE,the superfine polytetrafluoroethylene（ PTFE） powder and polyformaldehyde（ POM） were used to prepare PTFE-POM composites. The effects of PTFE fine powder content on mechanical property,processing fluidity and the wear-resisting properties of the composites were studied. Moreover,the microcosmic structure was analyzed through SEM. The results indicate that with the increase of PTFE content,the PTFE-POM compound material has better processing liquidity and wear resistance,though the mechanical properties decrease to some extent. SEM results reveal that the lower mechanical properties are caused by the partly compatibility of the PTFE powder and POM; owing to the isolation effect of PTFE powder,the processing flow of this material is remarkably improved; in the process of injection molding,the migration effect has promoted the wearability of the promising material significantly. Meanwhile,the cost of the PTFE-POM composite prepared in this paper is equal to the Du Pont commercialized AF500,but the performance especially the abrasion resistance is considerably better than that of AF500. Thus,the composite material is hopeful to take place of AF500 as wearable engineering plastics structural material.