Effect of monomer type and dangling end size on polymer network synthesis

The design of novel biomaterials for applications in biological recognition, drug delivery, or diagnostics requires a judicious choice of preparation conditions and methods for the production of well-characterized 3-dimensional structures, preferably by benign processes. In this work, the polymerization of poly(ethylene glycol) (PEG) methacrylates was examined by kinetic gelation modeling and kinetic analysis in order to ascertain the factors affecting the resulting structure. The kinetics of the polymerization and structure of the final polymer network are strongly affected by the length of the PEG graft chain. The propagation of the polymer chains becomes increasingly diffusion limited with the incorporation of longer PEG grafts. In addition, a more heterogeneous network consisting of numerous microgel regions is produced as the length of the PEG graft is increased. (C) 2003 Wiley Periodicals, Inc.