Reactions of macro‐ions resulting in the formation of block and graft copolymers. Grafting of polymers with aromatic groups

Abstract

AbstractGrafting of poly(oxytetramethylene) (polytetrahydrofuran) chains containing living oxonium end groups onto polymers containing aromatic rings was investigated. The rate of grafting was found to be slow, but under favourable conditions several moles of polytetrahydrofuran can be grafted to one mole of polystryrene. Macrocations may also be grafted to the surface of in‐soluble polymers dispersed in a solution of grafting ions. This was proved by grafting living polytetrahydrofuran onto poly(phenylene oxide) or random poly(1‐butene‐co‐styrene). Macro‐cations can be prepared from an anionic living polymer via transformation of the growing centers. Thus, poly(dimethylsiloxane), whose original anionic centers were transformated into cationic ones, was grafted to polystyrene. Exchange reactions were found to take place in the living system on polytetrahydrofuran or poly(dimethylsiloxane) grafts, thus influencing their length. The graft copolymers are strong surfactants. Separation from their mixture with homo‐polymers by a repeated extraction of homopolymers with a solvent is difficult and sometimes impossible.