Study On Flame Retardant Properties Of Surface Modification Attapulgite/PBT Composites

Polybutylene terephthalate(PBT)is one of the engineering plastics.It has been widely used cause good comprehensive properties,low cost,high heat resistance,high toughness,good electrical properties,rapid injection molding and other advantages.The flame retardant grade of pure PBT is only HB,which can not meet the use requirements.So the flame retardant properties of PBT needs to be improved by adding flame retardant.Traditional halogen-free flame retardants will produce toxic gases during burning,which has inevitable use limitations.Therefore,the development of halogen-free flame retardants is the research hotspot of flame retardant of PBT.In this paper,attapulgite(ATP)was treated by different surface modification methods and the effect of it was studied.The surface modified ATP/PBT composites were prepared.The effects of different modification methods and content of ATP on the flame retardancy and mechanical properties of PBT were studied.ATP/intumescent flame retardant(IFR)/ PBT composites were prepared.The synergy effects of ATP and IFR on the flame retardancy and mechanical properties of PBT were studied.The main research contents and conclusions are summarized as follows:(1)Surface modified ATP was prepared and the effects of different modification methods on the structure and properties of ATP were studied.The results show that the ball milling modification has the best effect on the modification of ATP and does not damage the crystal structure and rod crystal structure of ATP,),which was modify by silane coupling agent KH-550 under certain ball milling conditions.The contact angle of the resulting ATP was increased by 189%,its specific surface area was increasedby218% and the volume of the bundles and the sedimentation rate were decreased.(2)The surface modified ATP/PBT composites were prepared,the effects of ATP surface modification methods on the flame retardancy and mechanical properties of PBT were studied.The results show that the addition of ATP is helpful to the formation of carbon,delay of combustion rate and improvement of flame retardancy of PBT.Compared with other sample ATP,the ball milling modified ATP(mp-ATP)has the best effect on improving flame retardancy and mechanical properties of PBT.The tensile strength of the resulting ATP composites increased by 2.9%,the peak heat release rate decreased by 70.2% and the total heat release decreased by 27.3%.(3)The mp-ATP/PBT composites were prepared,the effects of the content of mpATP on the flame retardancy and mechanical properties of PBT were studied.The results show that,when the addition of mp-ATP is 11%,the flame retardancy and mechanical properties of mp-ATP/PBT composites are the best.The tensile strength of the resulting composites is increased by 2.9%,the peak heat release rate is reduced by 70.2% and the total heat release is reduced by 27.3%.(4)The mp-ATP/IFR/PBT composites were prepared.The synergy effects of mp-ATP and IFR on the flame retardancy and mechanical properties of PBT were studied.The results show that,when the ratio of composite is 9% mp-ATP/13% IFR /PBT,it has the best comprehensive properties,the peak heat release rate decreases by27.1% and the total heat release decreases by 31.2%.