Synthesis of Branched Polymers by Means of Living Anionic Polymerization, 5. Synthesis of Star Polymers by Reactions of End-Functionalized Polystyrenes with Chloromethylphenyl Groups with Polymer Anions Consisting of Two Polymer Chains

Well-defined five-arm star polymers, having different arms in molecular weight or composition, were synthesized by linking reactions of end-functionalized polystyrenes with two chloromethylphenyl (CMP) groups and polymer anions consisting of two identical or different polymer chains. The polymer anions were prepared by coupling living anionic polymers of styrene or isoprene with 1,1-diphenylethylene (DPE)-end-functionalized polymers. They were then reacted in situ with the CMP-end-functionalized polystyrenes to afford heteroarm star polymers of the AA′2A″2, AA′2B2, and AB2C2 types where the A, B, and C segments were polystyrene, poly(a-methylstyrene), and polyisoprene, respectively. 1H NMR spectroscopy, SEC, vapor pressure osmometry (VPO), and static light scattering measurements evaluated the well-defined architecture of these polymers.