The preparation of hyperbranched aromatic and aliphatic polyether epoxies by chloride-catalyzed proton transfer polymerization from AB_n and A₂ + B₃ monomers

Hyperbranched polymers consisting of aromatic or aliphatic polyether cores and epoxide chain-end peripheries were prepared by proton transfer polymerization. AB₂ diepoxyphenol monomer 1 proved to be well suited for the preparation of hyperbranched aromatic polymer 2 by this proton transfer polymerization. The use of chloride-ion catalysis, rather than conventional base catalysis, for the preparation of polymers from diepoxyphenol 1 offered a unique method to control the ultimate molecular weight of the polymer product through variations of the initial concentration of monomer 1 in tetrahydrofuran. An alternative route to hyperbranched polyether epoxies made use of commercially available or easily prepared aliphatic monomers of the types AB₂, AB₃, and A₂ + B₃. Although these aliphatic polymerizations can be initiated with a base, chloride-ion catalysis proved most effective for controlling the polymerization. The hyperbranched epoxies were characterized by NMR spectroscopy, gel permeation chromatography, and multi-angle laser light scattering. Chemical modification of the polymers after polymerization was carried out via nucleophilic addition on the epoxide groups or derivatization of the hydroxy substituents within the hyperbranched polymer structure. Spectroscopic measurements suggested that some such ring-opened materials may adopt reverse unimolecular micellar structures in appropriate solution environments.