Synthesis and thermal properties of bismaleate and bisfumarate telechelic oligomers from hydroxytelechelic polybutadienes

The preparation of original telechelic bismaleate and bisfumarate polybutadienes and their thermal properties are presented. These functional oligomers were synthesized by the esterification of a hemiester of maleic anhydride and methanol or an ethyl hemiester fumarate with hydroxytelechelic polybutadiene (HTPBd) in 94 and 63% yields, respectively. The thermal and thermomechanical properties of the materials obtained from the radical copolymerization of these telechelic bismaleate and bisfumarate polybutadienes with hexane-1,6-dimethacrylate (HDDMA) were investigated and compared to those of a classic polyurethane (PU) resin prepared from HTPBd and hexamethylene diisocyanate. Calorimetry identified only one glass transition temperature of -75°C assigned to the polybutadienic backbone for all three resins, while a second transition at 48°C attributed to the methacrylate network and was noted by thermomechanical analysis. Both bismaleate and bisfumarate oligomers led to materials having a slightly better thermal stability than that of the PU resin. Thermomechanical analyses indicated that the elastic moduli of the materials achieved from bismaleate and bisfumarate oligomers are higher than that of the PU resin, whatever the temperature.