Coatings that feature covalent-like fastness can be bonded non-covalently to low-surface-energy polymers: Evidence supporting the stepwise intercalation, activation and cross-linking of reactable monomers

In developing a new technique to surface-functionalize low-surface-energy polymers, injection-molded polypropylene was incubated in solutions that encouraged inter-molecular chain separation of surface-positioned polymeric chains and entry of small, monomeric precursors into the sub-layers. The precursors, namely, organosilanes such as aminopropyltrimethoxysilane, were transformed into the reactive silanol species in a following step in which the activator, namely water, was delivered to the site of occupation using the same solvent system. Once activated, conditions were established that would encourage individual monomers to cross-link while in the polypropylene matrix. The binary network afforded, for example, polyaminopropylsiloxane entangled within polypropylene, described a system in which two interconnected polymers shared no formal covalent bonds but nevertheless were inseparable. The generality, novelty and beneficial aspects of this approach will be presented in detail.