Preparation And Study On Property Of Zinc Borate Composited Flame-retardant PET

In this study,flame retardant PET was prepared via in situ polymerization in the presence of CEPPA as phosphrous flame retardant.As co-flame retardant,zinc borate(ZB)was added in situ or by melt blending,respectively.Finally,PTFE was chosen as anti-dripping agent in order to further improve the comprehensive flame retardant property.The intrinsic viscosity,thermal properties,combustion performance,anti-dripping property and the morphology of the char residues after combustion were characterized by means of Ubbelohde viscometer,differential scanning calorimetry,thermogravimetry,limiting oxygen index instrument,cone calorimeter and scanning electron microscopy.The results showed that,for the samples of in situ addition of ZB(less than 0.2%),the limiting oxygen index was increased to 27% and the mass of residual carbon char was also increased,compared to neat PET.In addition,the suppression of smoke release was improved.When CEPPA and ZB were added(PET/P/ZB series),the LOI was further increased to 29%.The surface of residual carbon layer was compact.Compared to the sample of PET/P,the numbers of melt drops of the samples decreased obviously during combustion because of ZB loading.The density of smoke release,however,kept almost unchanged.For the samples of ZB addition by melt blending,the results showed that ZB produced a greatly positive effect on the decrease of dripping,but had little effects on the suppression of smoke release.After a part of ZB was substituted with the same amount of PTFE,we found a synergistic effect that the suppression of smoke release and the anti-dripping property were detected simultaneously.In this study,the sample which containing 4% of ZB and 1% of PTFE showed the best comprehensive flame retardant property.