New telechelic polymers and sequential copolymers by polyfunctional initiator-transfer agents (inifers). VII. Synthesis and characterization of α,ω-di(hydroxy)polyisobutylene



A new telechelic polyisobutylene diol, HO[BOND]CH2[BOND]PIB[BOND]CH2[BOND]OH, carrying two terminal primary hydroxyl end groups has been prepared from α,ω-di(isobutenyl)polyisobutylene, CH2[DOUBLE BOND]C(CH3)- CH2[BOND]PIB[BOND]CH2C(CH3)[DOUBLE BOND]CH2, by regioselective hydroboration followed by alkaline hydrogen peroxide oxidation. Infrared (IR) spectra, 1H-NMR analysis of the pure and silylated products, and ultraviolet (UV) spectra of phenylisocyanate-treated diols indicate quantitative yields and two [BOND]CH2OH termini per polyisobutylene chain. The viscosity of HO[BOND]CH2[BOND]PIB[BOND]CH2[BOND]OH is higher than that of the starting α,ω-diolefin. The telechelic diol prepolymer opens new avenues to the synthesis of many new materials, e.g., polyurethanes.