High-Performance Preparation of Polymer Particle by Emulsion Polymerization via Polymerization Induced Self-Assembly Mechanism

Abstract

This research aims to compare the particle nucleation mechanism in an emulsion polymerization for polymer particle preparation. The recent particle formation as polymerization induced self-assembly (PISA) was used to produce the polymer particles containing positive charge on their surface compared with the well-known mechanism as homogeneous nucleation in emulsion conventional polymerization (emulsion CRP) without an emulsifier. It is well-known that the PISA can be used in various controlled/living polymerization techniques. In this work, the polymer particle was polymerized via emulsion iodine transfer polymerization (emulsion ITP). The positive charge polymer chain of 12 repeating units of poly([2-(methacryloyloxy) ethyl] trimethyl–ammonium chloride)12- iodide (PMTMA12-I) was firstly polymerized before being used as macro-chain transfer agent and emulsifier in the emulsion ITP of poly(methyl methacrylate) (PMMA) to obtain block copolymer of PMTMA₁₂-b-PMMA₅₀₈. The particle size and particle size distribution, the positive charge on their surface and polymerization rate were investigated for both mechanisms. It was found that using emulsion ITP, the polymerization rate was not different from emulsion CRP. In addition, the particle size (227 nm) and particle size distribution (PDI = 1.11) were smaller and narrower for emulsion ITP than those of emulsion CRP (232 nm and PDI = 1.22, respectively). It may be due to a higher positive charge (+59.86 mV) of emulsion ITP than it's (+39.65 mV) of emulsion CRP. For all results indicated that emulsion ITP represents high performance for PMTMA₁₂-b-PMMA₅₀₈ particle preparation.