화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.56, No.47, 14069-14077, 2017
Shape Memory Properties of Epoxy/PPO-PEO-PPO Triblock Copolymer Blends with Tunable Thermal Transitions and Mechanical Characteristics
In this paper, we report a simple method to prepare novel, transparent, hard-tough and hard-flexible shape memory, and soft-flexible epoxy polymers based on poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (PPOPEOPPO) triblock copolymer (TBCP) and diglycidyl ether of bisphenol A (DGEBA)/4,4'-diaminodiphenylmethane (DDM) system. The PPOPEOPPO triblock copolymer was used to tailor cross-link density and flexibility in epoxy thermosets and thereby their glass transition temperatures (T-g's). The formed blends exhibit a phase-separated morphology. The phase separation was initiated by immiscible PPO blocks via self-assembly. Three types of shape memory polymers, viz., stiff, intermediate, and soft-flexible epoxy systems, with entirely different physical and mechanical properties were prepared only by adjusting the blend composition. All the blends were UV resistant, were thermally and dimensionally stable, and could be used for various outdoor applications. To the best of our knowledge, no work has been reported on the shape memory properties of epoxy modified block copolymers.