Fabrication and mechanical properties of knitted dissimilar polymeric materials with movable cross-links

Abstract

Bulk polymerization of liquid main chain monomers in the presence of a linear polymer bearing acetylated γ-cyclodextrin (TAcγCD) (primary polymer) results in composite materials consisting of dissimilar polymer chains, hereinafter called the designs of movable cross-network elastomer knitting dissimilar polymers (KP elastomers). The post polymerized chains (secondary polymer) penetrate cavities in the TAcγCD units and form movable cross-links that connect between the primary and secondary polymers. The KP elastomers successfully improve the mechanical properties based on two key design components. One is a long movable range. The secondary polymers easily move in the TAcγCD cavities on the primary polymers due to the lack of a chemical cross-linker between the primary and secondary polymers. Thus, the KP elastomers exhibit high toughness because the movable cross-links are not fixed, which results in effective stress dispersion. The other is the synergistic effect of the multiphase structure. The network designs of the KP elastomers enable composite materials with movable cross-links that can even connect immiscible polymers, namely, poly(ethyl acrylate) (PEA) and polystyrene (PS). The obtained materials contain a three-phase structure: PEA, PS, and a mixed phase. The synergistic effect of the three-phase structure simultaneously improves the toughness and stiffness.