Preparation And Study On Property Of Frpet Composites With Dripping Resistance

In this study,the intumescent flame retardants(IFR)were prepared via combination of T-ester,which is the esterfication product between tris(2-hydroxyethyl)isocyanurate(THEIC)and purified terephthalic acid(PTA),and ammonium polyphosphate(APP).The preformed IFR was melt blended into phosphorus-containing flame retardant polyethylene terephthlate(FRPET)with F-compound as dripping resistant agent.Infrared spectroscopy(IR)was used to characterize the structure of IFR.Differential scanning calorimeter(DSC),thermogravimetric analysis,limit oxygen index test(LOI),micro-scale combustion calorimetry(MCC),conical calorimetry test(CONE),RH-7 capillary rheometer,rotational rheometer et al were used to respectively investigate the thermal properties,thermal stabilities,combustion performance,anti-dripping performance and rheological properties of FRPET.The results showed that,compared to FRPET,the initial decomposition temperature of FRPET/IFR ranged between 326℃and 334℃is lower than that of FRPET(i.e.383℃).However,the char performance is enhanced,with the char residual at 700 C increased by 54%-70%.The addition of IFR/PTFE caused the decline of the crystallization temperature(T_c)in a certain range.However,the glass-transition temperature(T_g)and melting temperature(T_m)didn’t have significant variation.FRPET with 15wt%of IFR/PTFE(in that,IFR/PTFE=1:2)can achieve the optimal flame retardancy in this study.The char residual increased by 68.7%at 700℃.The LOI also increased from 25%to 31%.Moreover,the amount of melt drops per minute decreases by54.3%relatively.The peak heat release rate(PHRR),total heat release(THR),the total smoke release(TSR),and the peak smoke release(PSR)decreased by 28.2%,23.9%,16.1%and 56.5%,respectively.The results of rheological property indicated that the composites shown pseudoplastic characteristics.The storage modulus(G’)and loss modulus(G’’)of the polymer composites increased due to the addition of PTFE.There appears the obvious effect of slowing relaxation modulus,demonstrated by appearance of plateau of modulus at lower frequency region.This is the indication of crosslink effect from PTFE,which is beneficial to increase the resistance of melt dripping.