Preparation Of PC/AES Alloy And Effects Of Different Flame Retardants On Its Properties

Polycarbonate?PC?and Acrylonitrile-ethylene-propylene-diene-styrene?AES?are two widely used engineering plastics.PC resin has high mechanical properties,creep resistance,dimensional stability,heat resistance,and good transparency,however,it also has defects,such as high melt viscosity,notch sensitivity,and processing difficulties.AES is a new type of resin,since the content of double bond in EPDM rubber molecular chain is low,AES overcomes the bad weather resistance of ABS,thus,it has excellent resistance to light and oxygen,good processing fluidity,low price,but,its heat resistance is poor,mechanical property is not ideal either.Therefore,the preparation of PC/AES alloy with excellent performance can make them realize advantageous complementarities in performance and broaden their application range.In this paper,on account of some shortcomings,such as the poor processing performance of PC and the poor mechanical performance of AES,a series of research work has been carried out from the point of view of improving the comprehensive performance of PC/AES.Firstly,PC/AES alloy with different AES content was prepared to research the effects of different AES contents on its properties;Then,efforts have been made to improve the performance of PC/AES alloy by adding maleic anhydride grafted styrene?SMA?compatibilizer to it;Finally,the flame retardancy modification of PC/AES alloy was carried out by three kinds of flame retardant systems,through the comprehensive analysis of mechanical properties,thermal properties,processing performance,flame retardant properties and morphology,we determined the optimal flame retardant system which can improve the comprehensive performance of PC/AES blends.The specific conclusions are summarized as follows:With the increase of AES content,the tensile and flexural strength of PC/AES alloy both decreased,the notched impact strength increased first and then decreased,the processing performance was improved to a great extent while the thermal stability was reduced.When the AES content was 30%,the comprehensive performance of alloy reached to the best.Therefore,the PC/AES alloy with 30%of AES was selected for the study of the compatibility and flame retardancy.With the increase of SMA content,the compatibility and mechanical properties of the compatibilized PC/AES alloy were increased first and then decreased,while the processing performance declined first and then improved.When the addition of AES was 8Phr,comprehensive performance of PC/AES blends compatibilized by SMA was the best,the glass transition temperature?Tg?of two phases approached to the closest in this case,mechanical strength reached to the maximum,and the alloy can also meet the processing requirements.Therefore,the compatibilized PC/AES alloy with 8Phr of SMA was selected for the study of the flame retardancy.The flame retardant modification of PC/AES blends with three kinds of flame retardant system was studied,they were decabromodiphenyl ethane and antimony trioxide?DBDPE/Sb₂O₃??bisphenol A bis?diphenyl phosphate??BDP??bisphenol A bis?diphenyl phosphate?and organic montmorillonite?BDP/OMMT?.When the addition of DBDPE and Sb₂O₃ were 16Phr and 4Phr,the PC/AES alloy had excellent flame retardancy,but the mechanical properties and processing performance were badly deteriorated.When the addition of BDP was 14Phr,the mechanical properties,processing performance and flame retardancy of PC/AES alloy were improved greatly,but still needed to be enhanced.When the addition of BDP and OMMT were14Phr and 3Phr,the comprehensive performance of flame retardant PC/AES alloy was the best,limiting oxygen index?LOI?was 35.5%,the vertical combustion reached to UL-94 V0 level.Compared with those without flame retardant,the tensile strength and flexural strength were both improved while the notched impact strength decreased.