Functionalized Copolymers of Isobutylene with Vinyl Phenol: Synthesis, Characterization, and Property

The random copolymers of isobutylene (IB) with polar comonomers of 4-acetoxystyrene (ACS) or 4- tert -butoxystyrene (TBO), P(IB- co -ACS) and P(IB- co -TBO), could be successfully synthesized via cationic copolymerization with FeCl 3 -based initiating system. The kinetics of the cationic copolymerization process was in situ investigated by inserting a diamond probe into the reaction system by ATR-FTIR spectroscopy. The chemical structure and incorporation content of polar comonomers in the copolymers were characterized by GPC with RI/UV dual detectors and 1 H-NMR spectroscopy. The corresponding functionalized random copolymers of IB with vinyl phenol P(IB- co -POH) carrying phenolic hydroxyl side groups could be further prepared via the complete hydrolysis of acetoxyl side groups in P(IB- co -ACS) or tert -butoxyl side groups in P(IB- co -TBO) copolymers. The functionalized P(IB- co -POH) copolymers became hydrophilic with water contact angle (WCA) of ca . 80° for the self-assembly in hot water, compared to the hydrophobic polyisobutylene with WCA of ca . 110°. The functionalized P(IB- co -POH) copolymers also displayed an excellent self-healing property due to the interaction of intermolecular hydrogen bonding and formation of three dimentional supramolecular networks from phenolic hydroxyl side groups. Furthermore, P(IB- co -POH) copolymers also provided a good matrix for the homogeneous dispersion for silica nanoparticles due to the formation of hydrogen bonding between copolymer chains and silica nanoparticles.