Research On High-quality Modified Bisphenol A Polycarbonate

Traditional polycarbonate is an excellent engineering plastics,but it has many defects,which restricts its application.In this paper,The copolymers of DMBPC(dimethyl bisphenol cyclohexane)and BPA(4,4'-isopropylidendiphenol)were prepared by the interfacial polycondensation and the homopolymerization process of DMBPC was investigated.Compared with BPA polycarbonate homopolymer,copolymer of DMBPC with BPA got great improvements in terms of the alkali resistance.The copolymers of TBBPA and bisphenol-A were prepared by the interfacial polycondensation and the homopolymerization process of TBBPA was investigated.The specific work is as follows:DMBPC polycarbonate was synthesized using DMBPC and phosgene via interfacial polycondensation.The molar ratio of DMBPC with BPA,catalyst type,the amount of catalyst,prepolymerization time,polycondensation temperature,prepolymerization temperature,feeding way of catalyst were investigated.The optimal reaction conditions were as follow:the molar ration of DMBPC to phosgene was 1:1.26,triethylamine as catalyst,the molar ration of DMBPC to trithylamine was 1:0.022,the molar ration of DMBPC to 4-tert-butylphenol was 1:0.030,prepolymerization temperature was run at 20?-25? for 30 minutes,polycondensation temperature35?-40?,the catalyst was divided into two times to join and the ration of catalyst was 1:10.The copolymers of DMBPC and BPA with phosgene were prepared by interfacial polycondensation.The way of copolymerization,the molar ratio of DMBPC with BPA,polycondensation temperature,polycondensation time were investigated.The results showed:DMBPC and BPA were conversed into chloroformate respectively before polycondensatio,the molecular weight distribution of copolymer was narrow and the reaction conversion was high.The optimal reaction conditions were as follow:the molar weight percentage of DMBPC was from 20%to 30%,polycondensation reaction was run at 35?-40? for 60 minutes.The purification process of DMBPC polycarbonate was improved,in which 4-methyl-2-pentanone was used as precipitant.TBBPA polycarbonate was synthesized with tetrabromobisphenol A and phosgene via interfacial polycondensation.The effects of the ratio of tetrabromobsphenol A to phosgene,catalyst type,the amount of catalyst,the amount of moleuclar weight regulater,prepolymerization time,feeding way of catalyst were investigated.The optimal reaction conditions were as follows:the molar ration of TBBPA to phosgene was 1:1.30,tetrabutylammoniun hydroide as catalyst,the molar ration of TBBPA to tetrabutylammoniun hydroide was 1:0.022,the molar ration of TBBPA to 4-tert-butylphenol was 1:0.030,prepolymerization temperature25?-30?,polycondensation temperature3 5 ?-40 ?,prepolymerization time 40 minutes,the catalyst was divided into two times to join and the ration of catalyst was 1:5.The way of copolymerization between DMBPC with TBBPA was investigated.