Multifunctional Polymer Particles Containing Quaternary Ammonium for Antimicrobial Particulate Surfactants and Defoaming

The preparation of multifunctional polymer particles containing quaternary ammonium molecules by emulsion iodine transfer polymerization (emulsion ITP) via polymerization-induced self-assembly was proposed for the first time. Poly(2-methacryloyloxy ethyl trimethyl ammonium chloride-dimethylamino ethyl methacrylate 12 alkyl chain length)-iodide (P(MTMA-QAC12)12-I) was first synthesized by solution iodine transfer polymerization. It was simultaneously used as a macro-chain transfer agent and emulsifier in emulsion ITP. All conditions smoothly proceeded without coagulation, where the polymerization reached high conversion within only 4 h. When the methyl methacrylate-styrene (P(MMA-S)) copolymer was synthesized in the second block as P(MTMA-QAC12)12-b-P(MMA-S)462, the water contact angle of the obtained particles was close to 90°, which was the most appropriate to use as the particulate surfactant. The P(MTMA-QAC12)12-b-P(MMA-S)462 particles represented a good antimicrobial property based on the positive charge quaternary ammonium groups existing on surfaces. Using such P(MTMA-QAC12)12-b-P(MMA-S)462 nanoparticles (∼90 nm) at 1 wt %, the obtained cutting oil emulsion model represented high colloidal stability with approximately 50 μm oil droplet size without any coalescence. Moreover, foam formation was significantly reduced compared to the commercial cutting oil. According to their excellent properties, P(MTMA-QAC12)12-b-P(MMA-S)462 nanoparticles would be effectively used as a particulate surfactant in Pickering emulsion, including defoamers and antimicrobial agents.