Room-temperature polydimethylsiloxane-based self-healing polymers

Polymers that respond in a productive fashion to their environment are under active development as they offer significant advantages over traditional materials. For example, polymers with the ability to self-heal and recover a significant fraction of their initial properties after being subjected to a damage event are of significant interest. Here we study the effect of healing agent viscosity and catalyst activity on self-healing at and near room temperature. The viscosity of the PDMS healing agent was varied from 14 to 40 000 cP, and the tin-based catalysts di-n-butyltin dilaurate, dimethyl-dineodacanoate tin, di-n-butyl bis(2-ethylenehexanoate), tin II oleate, and tetrakis(acetoxydibutyl tinoxy)silane were studied. Both vinyl ester and epoxy matrices were investigated. By optimizing the viscosity of the PDMS healing agent and the catalytic activity, as well as selection of the appropriate adhesion promoter, a PDMS-based self-healing system which healed at room temperature was obtained.