Successive Synthesis of Well-Defined Many Arm Star-Branched Polymers by an Iterative Methodology Using a Specially Designed 1,1-Diphenylethylene

Abstract

The synthesis of well-defined regular and asymmetric star-branched polymers having as many as 63 arms, each of similar or different composition, is described. This synthesis has been achieved by developing a new, iterative methodology using a specially designed functionalized reagent, 3,5-bis(3-(4-(1-phenylethenyl)phenyl)propoxy)benzyl bromide (5). This reagent is capable of introducing two 1,1-diphenylethylene (DPE) functions via one reaction site. The methodology involves only two sets of reactions for entire iterative reaction sequence: (a) an addition reaction of living anionic polymer(s) to DPE-chain-functionalized polymer to link polymer chain(s) and (b) an in situ substitution reaction of 5 with 1,1-diphenylalkylanions newly generated after the addition reaction. Two DPE functions are introduced per one anion. With this methodology, well-defined 3-, 7-, 15-, and 31-arm followed by 63-arm regular star-branched polystyrenes as well as 3-arm AB2, 7-arm AB2C4, and 15-arm AB2C4D8, followed by 31-arm AB...