New phosphate glass/polymer hybrids - Current status and future prospects

The physical modification of polymer structure and properties via polymer blending and reinforcement is a common practice in the plastics industry and has a large economic advantage over synthesizing new polymeric materials to fulfill new material needs. In this context, a new class of inorganic glass/organic polymer hybrids with enhanced benefits has been recently developed by blending low-Tg phosphate glasses with polymeric materials in the liquid state, to afford new hybrid materials with significant improvements in properties that are impossible to achieve from classical polymer blends and composites. Because of their facile synthesis and desirable characteristics, these phosphate glass/polymer hybrid materials may be model systems for exploring feasibility of new routes for driving inorganic glasses and organic polymers to self-assemble into useful materials. Conceptually, it may even be possible to use block copolymers, with one block being miscible with Pglass, to perform self-directed assembly of nanostructured hybrids, where the Pglass is confined solely to one phase. This article reviews some new insights into the structural dynamics, melt rheology, molecular relaxation processes, and phase behavior of a few representative examples of these unique hybrid materials with prescribed rheological properties, macromolecular structure and function. The unanswered questions are discussed to guide future research directions, and facilitate progress in this emerging area. (C) 2007 Elsevier Ltd. All rights reserved.