Shape Memory and Self-Healing Properties of Poly(acrylate amide) Elastomers Reinforced with Polyhedral Oligomeric Silsesquioxanes

The organic–inorganic nanocomposite elastomers were synthesized via the random copolymerization of 5-acetylaminopentyl acrylate (AA) with 3-methacryloxypropyl heptaphenyl polyhedral oligomeric silsesquioxane (MAPOSS). The morphological results showed that the random copolymers were microphase-separated and the POSS structural units were aggregated into the nanodomains that were composed of tens of silsesquioxane cages. Compared to neat PAA, the organic–inorganic copolymers possessed enhanced glass transition temperatures and improved mechanical strengths. Most importantly, the organic–inorganic copolymers simultaneously had shape memory and self-healing properties. The shape memory properties can be attributed to the formation of physical cross-linking in the random copolymers; in the physically cross-linked network, the POSS nanodomains constituted the net points. The self-healing properties are responsible for the dynamic exchange of the intramolecular hydrogen bonds among acrylate amide groups in spite of the nanoreinforcement of POSS nanodomains. The formation of microphase-separated morphologies is critical for the organic–inorganic copolymers simultaneously to have the shape memory and self-healing properties.