Preparation And Study On Structure And Property Of Flame Retardant PA6

Flame retardant PA6 was prepared by melt blending with pentaerythritol phosphate(PEPA),aluminum diethyl phosphinate(ADEP)and melamine phosphate(MPP)as additive falme retardants.Then,the influence of the amounts of flame retardant in PA6 on structure and properties was studied,as well as the synergistic effect of PEPA/ADEP and PEPA/MPP on PA6.In addition,the spinning performance of the flame retardant PA6 was also investigated.The morphology,structure,crystallinity,thermal properties,mechanical properties and flame retardancy of PA6 were characterized by means of SEM,FTIR,XRD,TG,DSC,Instron material testing machine,LOI,vertical combustion and cone.PEPA played a role of plasticizer in PA6.The glass transition temperature,cold crystallization and melt crystallization temperature of PA6/PEPA decreased.In addition,PEPA(20wt% addition)showed a positive effect on the flame retardancy of PA6,leading to a solid residue,LOI,and UL-94 rate of 16.3%,27%,and V-2,respectively.Total heat release and mass loss rate and total combustion time decreased during cone calorimetry test.The modified PA6 samples with no more than 7wt% of PEPA showed good spinning performance.The addition of ADEP to PA6 leads to the decrease of the crystallization temperature,melting temperature and initial pyrolysis temperature of PA6.Similarly,the flame retardant of PA6 increases obviously with LOI up to 34% and UL94 rate of V-0 when the ADEP content was 20wt%.In cone test,the p HRR and THR decreased.However,the mechanical properties decreased and spinnability deteriorated because of the poor compatibility and dispersion of ADEP in PA6 matrix.Combination of PEPA/ADEP had no synergistic flame retardant effect in PA6.On the other hand,the combination of PEPA/MPP(15:5)showed good flame retardant synergistic effect on PA6 The blends contains PEPA/MPP of 20wt% received V-2 UL-94 rate and LOI of 28%.The p HRR and THR decresed and the solid residue increased campare with pure PA6.