Study On Flame Retardant HDPE With Aluminium Hydroxide/nano Carbon Material Complex

Polyolefin is the most commonly used polymer materials all over the world, but it’s highly flammable characterlimits its application in the field where higher flame retardant level is required. Traditional halogen flame retardant is more limited than ever with the gradually strengthened global environmental protection consciousness, so halogen free, low smoke, low toxicity, environmentally friendly flame retardant polymer materials has become the pursuit goal of people. Inorganic flame retardant system is one of the earliest type of flame retardant system, but lower efficiency has been seriously restricting its application. This article discusses the effect of fullerene (C60) and nano carbon black (CB) on the flame retardant properties of HDPE/aluminum hydroxide (ATH) composites, based on the flame retardant mechanism of this sytem.HDPE/ATH/C60 composites were prepared by melt blending and their flame retardancy and thermal stability were studied. TEM tests showed C6o was dispersed with micron grade in the matrix. Vertical combustion tests showed that a UL-94 V-0 rate is achieved by adding 3 portions of C60 into HDPE/ATH (ratio:100/120) composites, and at the same time the LOI increased about 2%. Cone tests revealed that C60 could extend the tign and tpHRR, and cut down the pHRR of HDPE/ATH composites. TG tests showed that C60 could improve the Tonset in both N2 and air atmosphere, while DSC tests showed a delay to the OIT. TG-FTIR. tests supported that C60 could absorb the free radicals produced at the beginning of degradation to form a cross-linked network which slows down the degradation of matrix and improves the flame retardancy of HDPE/ATH composites.Using silane coupling agent KH-550 to process ATH and C60 powder, HDPE/ATH/KH-550/C60 composites were prepared by melt blending and their flame retardancy and thermal stability were studied. TEM tests showed C60 was better dispersed in the matrix. Vertical combustion tests showed that a UL-94 V-0 rate is achieved by just adding 1 portion of modified C60 into HDPE/ATH (ratio:100/120) composites, but the LOI didn’t change too much. Cone tests revealed that modified C60 could impressively extend the tign and tpHRR, and cut down the pHRR of HDPE/ATH composites while DSC tests showed a better improvement on OIT.HDPE/ATH/CB composites were prepared by melt blending and their flame retardancy and thermal stability were studied. Vertical combustion tests showed that a UL-94 V-0 rate is achieved by adding 10 portions of CB into HDPE/ATH (ratio:100/80) composites, and at the same time the LOI increased about 3%. Cone tests revealed that low loading of CB could cut down the pHRR, Avg SEA, CO and CO2 yeild of HDPE/ATH composites while high loading of CB could increase these parameters. TG tests showed CB could effectively improve the Tonset in N2 atmosphere, while DSC tests showed a great increment on OIT. The results supported that CB could also absorb the free radicals produced at the beginning of degradation to form a cross-linked network which slows down the degradation of matrix and improves the flame retardancy of HDPE/ATH composites.