Title

Site Transformation of Polyisobutylene Chain Ends into Functional RAFT Agents for Block Copolymer Synthesis

Document Type

Article

Publication Date

4-1-2009

Department

Polymers and High Performance Materials

Abstract

Block copolymers consisting of polyisobutylene (PLB) and either poly(methyl methacrylate) (PMMA) or polystyrene (PS) block segments were synthesized by a site transformation approach combining living cationic and reversible addition-fragmentation transfer (RAFT) polymerizations. The initial PIB block was synthesized via quasi-living cationic polymerization using the TMPCl/TiCl(4) initiation system and Subsequently converted into a hydroxyl-terminated PIB. Site transformation of the hydroxyl-terminated PIB into a macro-chain-transfer agent (PIB-CTA) was accomplished by N,N'-dicyclohexylcarbodiimide/dimethylaminopyridine-catalyzed esterification with 4-cyano-4-(dodecylsulfanylthiocarbonylsulfanyl) pentanoic acid. Structure of the PIB-CTA was confirmed by both (1)H and (13)C NMR spectroscopy. The PIB-CTA was then employed in a RAFT polymerization of either methyl methacrylate or styrene, resulting in PIB block copolymers with narrow polydispersity index and predetermined molecular weights confirmed by both (1)H NMR and GPC.

Publication Title

Macromolecules

Volume

42

Issue

7

First Page

2353

Last Page

2359