Acyclic diene metathesis (ADMET) segmented copolymers

A series of segmented copolymers was synthesized via acyclic diene metathesis (ADMET) chemistry by copolymerizing either an aliphatic carbonate hard segment diene or an aromatic ester hard segment diene with a telechelic oligomer soft segment diene of either poly(tetramethylene oxide) or polyisobutylene. The thermal behavior of these copolymers was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The data show that these unsaturated copolymers are semicrystalline, thermally stable materials which exhibit phase separation between the hard and soft phases. The carbonate copolymers were hydrogenated to yield saturated counterparts which display an increase in melting temperature when compared with their unsaturated analogues while maintaining approximately the same glass transition temperature. In some cases hydrogenation also led to the appearance of two melting endotherms.