微相分离结合氢键复合构筑弹性体

By integrating the microphase separation and hydrogen-bonding complexation, here, triblock copolymer polystyrene-b-poly(acrylic acid)-b-polystyrene (SAS) and homopolymer poly(ethylene oxide) (PEO) were used to construct the elastomer (SA/E) with different hierarchical structures. Poly(acrylic acid) (PAA) and PEO can form flexible and stretchable hydrogen-bonded complex. Polystyrene (PS) is neither compatible with PAA nor PEO, and the microphase separation structure will be formed when SAS is associated with PEO. The vitrified PS domains acted as physical cross-link points for soft PAA/PEO hydrogen-bonding complex domains. Compared with PAA/PEO homopolymer hydrogen-bonding complex, the SA/E elastomer shows higher modulus and strength, while maintain the considerable breaking elongation. By changing the PS molecular weight fraction, the SA/E can assemble to various microphase structures and present different mechanical and elastic properties. In addition, the SA/E shows excellent humidity adaptable behavior. The SA/E has different mechanical strengths at different relative humidity conditions. The moisture absorbed in SA/E can serve as plasticizer to enhance the flexibility of PAA/PEO hydrogen-bonding complex domains. Moreover, by cyclic stretching-releasing training, the elastic recovery ratio of SA/E is significantly improved, up to 98%. The elastomer has potential application in smart sensors, flexible devices, and advanced medical materials. This research also provides new methods and ideas for constructing new elastic materials.