Synthesis Of Polystyrene-b-Polycarbonate-b-Polystyrene And Polycarbonate-g-Polystyrene By The Combination Of Condensation Polymerization And Atom Transfer Radical Polymerization

In the present dissertation, three copolymers with well-defined architectures, PSt-b-PC-b-PSt, PC-g-PSt and (PSt)2PC(PSt)2 were synthesized by the combination of condensation polymerization and atom transfer radical polymerization(ATRP).In the first part of this dissertation, 2-(4-hydroxyphenyl)-2-(4-(a-bromoisobutyryloxy)phenyl)propane (I) was synthesized by reacting bisphenol A with a-bromo isobutyryl bromide and purified by column chromatogram. Then, polycarbonate with one bromoisobutyrylate groups at each end was prepared by using I as the end-capping agent in the condensation polymerization of bisphenol A with triphosgene. Its molecular weight and structure were determined by GPC, ]H NMR or bromide content analysis. Lastly, this difounctional polycarbonate was used as the macroinitiator for the ATRP of styrene to prepare triblock copolymer of PSt-b-PC-b-PSt. In order to confirm the blocking polymerization was a controlled/living process, the dependence of molecular weight of polystyrene outer block on monomer conversion was investigated through the hydrolysis of the polycarbonate central block by potassium hydroxide.In the second part of this dissertation, a functional polycarbonate was prepared through copolymerization of triphosgene with bisphonel A and l,l-bis-(4- hydroxyphenyl)-!-(4-(a-bromoisobutyryloxy)phenyl) ethane, which was syhthesized by reacting 1,1 ,l-tris(4-hydroxyphenyl)ethane with ct-bromo isobutyryl bromide. Then, ATRP of styrene was carried out in the presence of the above functional polycarbonate, resulting a graft copolymer of PC-g-PSt.In the last part of the dissertation, another functional polycarbonate was synthesized by using l-(4- hydroxyphenyl)-1,1-bis(4-(a-bromoisobutyryloxy)phenyl)ethane as an end-capping agent. Due to that polycarbonate obtained above had two bromoisobutyrylate groups at each end, (PSt)2PC(PSt)2 could be generated with the polycarbonate as an initiator in the ATRP of styrene.