Amphiphilic conetworks. III. Poly(2,3‐dihydroxypropyl methacrylate)–polyisobutylene and poly(ethylene glycol) methacrylate–polyisobutylene based hydrogels prepared by two‐step polymer procedure

This article describes the synthesis and characterization of new amphiphilic polymer conetworks containing hydrophilic poly(2,3‐dihydroxypropyl methacrylate) or poly(ethylene glycol) methacrylate (PEGMA) and hydrophobic polyisobutylene chains. This conetworks were prepared by a two‐step polymer synthesis. In the first step, a cationic copolymer of isobutylene and 3‐isopropenyl‐α,α‐dimethylbenzyl isocyanate (IDI) was prepared. The isocyanate groups of the IB‐IDI random copolymer were subsequently transformed in situ to methacrylate (MA) groups in reaction with 2‐hydroxyethyl methacrylate (HEMA). In the second step, the resulting MA‐multifunctional PIB‐based crosslinker, PIB(MA)_n, with an average functionality of approximately four per chain, was copolymerized with 2,3‐dihydroxypropyl methacrylate or poly(ethylene glycol) methacrylate by radical mechanism in tetrahydrofuran giving rise to amphiphilic conetworks containing 11–60 mol % of DHPMA or 10–12 mol % of PEGMA. The synthesized conetworks were characterized with solid‐state ¹³C‐NMR spectroscopy and differential scanning calorimetry. The amphiphilic nature of the conetworks was proved by swelling in both water and n‐heptane. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4074–4081, 2007