Preparation Of PC/ASA Alloy And The Effects Of Different Flame Retardant On Its Properties

PC(Polycarbonate)is a kind of polymer which contains carbonate bond,ASA is the terpolymer of acrylonitrile-styrene-acrylate.Both of PC and ASA resin are widely used engineering plastics.PC resin has high thermal stability,melting temperature,transparency,as well as good mechanical properties and deformation resistance.However,it's sensitive to notches,and the high viscosity of melt makes it difficult to be processed.Compared with ABS resin,ASA resin has better weathering resistance because the acrylic rubber doesn't contain double bond.Besides,it also has good mechanical properties and processing fluidity,However,there is still room for improvement in heat resistance.The preparation of PC/ASA alloy not only can improve the processing fluidity of PC resin,but also strengthen the heat resistance of ASA resin.Therefore,PC/ASA alloy with excellent comprehensive properties will have high market value.In this paper,the effects of different ASA resin content on PC/ASA alloy properties were studied by blending PC resin and ASA resin.With the increase of ASA resin content,the tensile strength and the flexural strength of the obtained alloy show a decreasing trend,while the notched impact strength show a trend of first rise and then decline.The microstructure,processing fluidity and glass transition temperature were investigated by SEM,torque rheometer,and DSC test.The results indicate that the processing fluidity,compatibility and comprehensive mechanical properties of PC/ASA alloy are the best when PC/ASA= 70:30.Furthermore,PC/ASA alloy modified with two kinds of compatibilizer,SMA(styrene-maleic anhydride graft copolymer)and E-MA-GMA(ethylene-methyl acrylate-glycidyl methacrylate),respectively,was prepared by melt compounding.Both of the compatibilizer SMA and E-MA-GMA could improve the compatibility of PC/ASA alloy,and the toughening effect of E-MA-GMA/PC/ASA alloy is better than that of SMA/PC/ASA alloy.On the other hand,the compatibilization effect of SMA/PC/ASA alloy is better than that of E-MA-GMA/PC/ASA alloy.To sum up,when the addition of SMA is 10 phr,the alloy shows the best mechanical properties and processing properties.Finally,four kinds of flame retardant,PX220(p-bis-(diphenylphosphoryloxy)-benzol,TPP(triphenyl phosphate),FCA107(silsesquioxanes,phenyl,hydroxyterminated)and OMMT(organically modified montmorillonite)were used to modify PC/ASA alloy.Both of PX220/PC/ASA and PX220/TPP/PC/ASA flame-retardant systems could maintain good processing fluidity.However,the loading of TPP would seriously affect the mechanical properties of PC/ASA alloy.Besides,PX220/PC/ASA and PX220/TPP/PC/ASA alloy could generate droplets during vertical combustion tests.PX220/PC/ASA couldn't reach V-0 grade,whereas appropriate proportion of PX220 and TPP could make the PC/ASA alloy reach V-0 grade.The combination of PX220 with FCA107 and OMMT could increase the carbon residue of PC/ASA alloy at 800? more obviously,at the same time,the limit oxygen index of PC/ASA alloy could also be greatly improved,and the Vertical combustion grade up to V-0.In particular,with the loading of OMMT,the thermal stability and combustion performance of PC/ASA alloy could be enhanced more obviously.Meanwhile,the two flame-retardant systems not only could enhance the flame retardant of PC/ASA alloy,but maintain the good mechanical properties as well.