Synthesis and characterization of polyisobutylene telechelic prepolymers with epoxide functionality

Syntheses of novel polyisobutylene telechelic prepolymers with various types of epoxide functionality, including aliphatic glycidyl ether, phenyl glycidyl ether, non-glycidyl aliphatic epoxide, and cycloaliphatic epoxide have been developed. The polyisobutylene prepolymers with aliphatic and phenyl glydicyl ether functionalities were achieved by reaction of primary alcohol-terminated and phenol-terminated polyisobutylene, respectively, with epichlorohydrin. Exo-olefin epoxide-terminated polyisobutylene was synthesized by direct epoxidation of exo-olefin-terminated polyisobutylene with a strong oxidizing agent, meta-chloroperoxybenzoic acid. The cycloaliphatic epoxide-terminated polyisobutylene was obtained by nucleophilic substitution of primary bromide end-functional polyisobutylene with a pre-formed potassium cyclohex-3-enecarboxylate salt, followed by epoxidation with meta-chloroperoxybenzoic acid. 1H NMR and MALDI-TOF mass spectrometry analyses demonstrated that the functionality for all types of epoxide prepolymers was 2.0. Gel permeation chromatography (GPC) analysis showed that targeted molecular weight and narrow molecular weight distribution were achieved for these prepolymers and no polymer chain degradation or coupling occurred during post-polymerization modifications. Polyisobutylene telechelic prepolymers carrying four different types of epoxide functionalities were synthesized by direct routes involving in situ quenching chemistry on living polyisobutylene. These materials include both aliphatic and aromatic glycidyl ethers suitable for reaction with amines and aliphatic and cyclohexene epoxides suitable for cationic ring-opening polymerization. [Display omitted] •Epoxide-terminated PIBs are synthesized by end-quenching of living polymers followed by post-polymerization modifications.•Epoxide-terminated PIBs include aliphatic and aromatic glycidyl ethers, exo-olefin epoxide, and cyclohexene epoxide types.•H NMR and MALDI-TOF mass spectrometry show that targeted epoxide (epoxy) end groups are obtained.