Carbon-carbon main chain polymer with accumulated oligo(ethylene glycol)-substituted cyclotriphosphazenes: Study on the LCST-type phase separation of organic-inorganic poly(substituted methylene)s

Abstract

The synthesis and characterization of organic-inorganic thermoresponsive poly(substituted methylene)s are described. Diazoacetates with oligo(ethylene glycol)-substituted cyclotriphosphazenes were synthesized, and the obtained products were employed as monomers for Pd-initiated polymerization to produce carbon–carbon main chain polymers bearing an oligo(ethylene glycol)-substituted cyclotriphosphazene on every main chain carbon atom. The resulting polymers with densely accumulated oligo(ethylene glycol) units around the polymer main chain showed lower critical solution temperature-type phase separation in an aqueous medium. Pd-initiated polymerization of diazoacetates containing oligo(ethylene glycol)-substituted cyclotriphosphazenes was conducted to yield carbon-carbon main chain polymers bearing an oligo(ethylene glycol)-substituted cyclotriphosphazene on every main chain carbon atom. The resulting organic–inorganic poly(substituted methylene)s were found to show an LCST-type phase separation in aqueous media, and thus their thermosensitive behavior was evaluated by turbidity measurements.