Design of a maleimide monomer to achieve precise sequence control and functionalization for an alternating copolymer with vinylphenol

We designed an N-phenylmaleimide derivative bearing an activated NHS ester (NHS-PhMI) for radical copolymerization with tert-butoxystyrene (tBOS) to achieve both precise alternating sequence control and functionalization. Essential to the monomer design is the electron-deficient carbon-carbon double bond for precise alternating propagation as well as the facile substitution reaction for the activated ester pendant. The precision of alternating sequences was evaluated by MALDI-TOF-MS analysis in comparison with a series of copolymers. Some amine compounds were quantitatively incorporated onto the maleimide side chain through the aminolysis reaction, whereas the tBOS units were transformed into vinylphenol counterparts via deprotection under acidic conditions. The resultant vinylphenol-based alternating copolymers showed unique solubilities and thermal properties depending on the substituent of the maleimide units.