Synthesis of Block Copolymer Particles by One-Pot, Two-Step Dispersion Reversible Chain Transfer Catalyzed Polymerization (Dispersion RTCP) in Supercritical Carbon Dioxide

Abstract

Direct synthesis of micrometer-sized, poly(methyl methacrylate)block-polystyrene (PMMA-b-PS) particles by one-pot, two-step dispersion reversible chain transfer catalyzed polymerization (dispersion RTCP) with nitrogen catalyst was successfully demonstrated in supercritical carbon dioxide (scCO 2 ). The molecular weight distribution was clearly shifted to higher molecular weight side compared to that of PMMA-I prepared in the first step, indicating the successful synthesis of the block copolymer. This was supported by thin-layer chromatographic result. The blocking efficiency, which was obtained from the two numberdistribution curves of molecular weight measured from gel permeation chromatography with dual detectors (refractive index and ultraviolet), was 87%.

Precipitation copolymerization of methyl methacrylate/meth‐acrylate acid in supercritical carbon dioxide

“…9 Due to the low solubility in CO 2 , most polymers can only be produced by heterogeneous polymerization, such as dispersion polymerization, 10 precipitation polymerization, [11][12][13] et al To the dispersion polymerization, the stabilizers are usually used to prevent the polymer particles from aggregation. For example, some monomers such as methyl methacrylate (MMA), styrene (St), N-vinylpyrrolidone (NVP), et al have been successfully polymerized by dispersion polymerization using fluorinated [14][15][16] or siloxane-based [17][18][19][20] polymers as the stabilizers. However, these stabilizers have potential environmental pollution problem, or high costs problem, which prohibits its wide application.…”

Preface to the Mohamed El-Aasser Festschrift

“…McKenna et al used reaction calorimetry to characterize reaction rates. The article by Okubo et al is on N -iodosuccinimide catalyzed reversible chain transfer dispersion polymerization of methyl methacrylate and styrene in supercritical CO 2 .…”