SYNTHESIS PROCESS OF STYRENE AND CARBOXYALKYLMALEIMIDE COPOLYMERS BY NITROXIDE-MEDIATED CONTROLLED POLYMERIZATION

Abstract

The present invention describes the synthesis process of novel sequential copolymers of styrene (St) and maleimides functionalized with alkylcarboxyl groups (MI-alkylcarboxyl). The copolymers were synthesized by nitroxide-mediated radical polymerization (NMP) via bimolecular initiation, performing sequential additions of MI-alkylcarboxyl comonomers, generating alternating blocks of P(St-alt-MI) which were subsequently extended with the residual St monomer present in the medium, forming the P(St-alt-MI)-PS sequences. This synthesis method makes it possible to obtain styrene-based copolymers with controlled incorporations of functionalized MI of less than 30 mol%.P(St-alt-MI)-PS-P(St-alt-MI)-PS- copolymers were obtained using two types of MI-alkylcarboxyl (N-carboxyhexylmaleimide and N-carboxyundecylmaleimide) and were characterized by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). The pseudo-living nature of the copolymerizations was confirmed by plotting the percentage conversion against time, monitoring the batch copolymerization kinetics. The synthesis of styrene copolymers functionalized with rigid P(St-alt-MI) blocks is of interest for generating low-cost thermoplastic-based polymer matrices, useful for dispersing metallic nanoparticles or as ion-exchange resins.