Thermoplastic amphiphilic conetworks

Our main objective was the design, synthesis, characterization, and testing of a novel class of materials, thermoplastic amphiphilic conetworks (TP‐APCNs). A further objective was the evaluation of TP‐APCNs as biomaterials, for example, as immunoisolatory membranes in a bioartificial pancreas, or as extended‐wear soft contact lenses. The synthesis of the first TP‐APCNs was accomplished by blending an amphiphilic graft polymer, poly(dimethyl acryl amide)‐g‐polydimethylsiloxane (PDMAAm‐g‐PDMS), with a commercial PDMS‐containing polyurethane (PU). The common PDMS segments coalesce and form a single phase, whereas the hard/crystalline segments of the PU physically crosslink the blend. The properties of TP‐APCNs can be controlled by the graft/PU ratio and segment molecular weights. TP‐APCNs with cocontinuous hydrophilic and hydrophobic phases were prepared as demonstrated by swelling in water and n‐heptane. Depending on the blend ratio and molecular weights, optically clear water‐swollen TP‐APCNs with 0.5–4 MPa tensile strength, 70–280% elongation, together with 2–11 × 10^?7 cm²/s glucose permeability, and 1.2–8 × 10^?8 cm²/s insulin permeability were prepared. TP‐APCNs are processible by casting and molding. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 682–691, 2009