Synthesis, characterization, and crosslinking of methacrylate-telechelic PDMAAm-b-PDMS-b-PDMAAm copolymers

The synthesis and molecular characterization of a new amphiphilic conetwork (APCN) designed for silicone hydrogel use is described. The synthesis strategy, outlined in Scheme 1, calls for the preparation, by the RAFT technique, of a new methacrylate-telechelic amphiphilic pentablock, MA-PHEA-b-PDMAAM-b-PDMS-b-PDMAAm-b-PHEA-MA, and its crosslinking to the target APCN. The sketch shows the architecture of the APCN (dotted lines, PDMAAm; solid lines, PDMS; clusters, MA-based crosslinking sites; see Fig. 3). All six synthesis steps proceed smoothly and efficiently, and the products are optically clear, colorless membranes exhibiting properties appropriate for ophthalmic use. (c) 2007 Wiley Periodicals, Inc.