Preparation And Properties Of Halogen-free Flame Retardant Glass-fiber Reinforced Nylon 6 Composites

Melamine polyphosphates(MPPs)were prepared at different temperatures and the resultant materials were characterized by FTIR,SEM,XRD and TG.Besides,tetraethylorthosilicates(TEOS)were added during the preparation process of melamine pyrophosphate(MPP)and modified MPPs(m MPPs)with different silica contents were obtained.Both MPP and m MPPs were characterized by FTIR,SEM,XRD and TG.Glass fiber(GF),m MPP,aluminum diethylphosphinate(ADP)and nylon6(PA6)were blended by molten blending and GF-reinforced flame retardant PA6 composites(GFRPA6)were obtained.These composites were characterized by mechanical testing instrument,vertical burning testing instrument and limited oxygen index(LOI)testing instrument.Results shows that the optimize synthesis temperature of MPP was310 ?,MPPs were modified successfully and the particle sizes of m MPPs were smaller than that of MPP,both MPP and m MPPs were orthorhombic crystals.With Si O2 increase the thermal stabilities of m MPPs increased firstly and then decreased,the thermal stabilities of m MPPs were higher than pure MPP.With Si O2 increase the tensile strength of GFRPA6 increased firstly and then decreased,while the impact strength decreased.As silica content was 6 wt% the tensile strength of GFRPA6 increased by 7% and reached the maxium value.As flame retardants(mixture of m MPP and ADP)was 18wt% all GFRPA6 reached UL94 V-0 rating and the limited oxygen indexes(LOI)were higher than 28.