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 (MA-POSS). 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.