玻纤对阻燃聚甲醛复合材料阻燃性能、力学性能及流变行为的影响研究

摘要

Glass fiber (GF) reinforced intumescent flame retardants (IFR) flame-retardant modified polyoxymethylene (POM) composites was prepared by melt blending method.Mechanical and flame retardant properties of the flame-retardant polyoxymethylene system were investigated by vertical combustion test,limit oxygen index test,simple beam pendulum impact testing machine and universal mechanics tester.The rheological properties of the composites were measured by a rotary rheometer.The results show that compared with unreinforced system,the tensile strength and bending strength of POM/IFR composite system reinforced by 20wt％ GF is increased by 15.8％ and 16.0％ respectively,and the impact strength is increased by 1 time.The POM/IFR/GF composites exhibits higher dynamic modulus and viscosity compared to the composites system without GF.Due to the "candle effect" from GF,POM/IFR/GF failed to achieve the UL-94 rating.After the surface modification of GF by phenolic resin,the limit oxygen index of POM/IFR/GF increases from 22.7％ to 34.6％,the mechanical properties are improved slightly,the modulus and viscosity of the system are lower than that of the system with unmodified GF.%采用熔融共混法制备了膨胀型阻燃剂(IFR)和玻纤(GF)增强改性的聚甲醛复合材料,利用垂直燃烧测试、极限氧指数测试、简支梁摆锤冲击试验机及万能力学测试仪考察了阻燃聚甲醛体系的阻燃性能及力学性能,并采用旋转流变仪测定了复合材料的流变性能.结果表明,质量分数为20％ GF的加入使聚甲醛(POM)/IFR复合体系的拉伸强度提升15.8％,弯曲强度提升16.0％,冲击性能提升1倍.与未添加GF的复合体系相比,POM/IFR/GF复合材料表现出更高的动态模量和复数黏度.由于GF“烛芯效应”的作用,GF的加入未实现UL94阻燃等级.通过酚醛树脂对GF进行表面改性(mGF)后,POM/IFR/GF复合体系的极限氧指数(LOI)由22.7％提升至34.6％,力学性能略有提升,体系的模量、复数黏度均低于未改性GF增强体系.