Synthesis of micrometer-sized poly(methyl methacrylate) particles by microsuspension iodine transfer polymerization (ms ITP)

Abstract

Micrometer-sized poly(methyl methacrylate) (PMMA) particles were successfully prepared without submicrometer-sized by-products for the first time by applying microsuspension iodine transfer polymerization with iodoform as a chain transfer agent.

Synthesis of Micrometer‐Size Poly(Methyl Methacrylate) Particles by Utilizing Microsuspension Iodine Transfer Polymerization (ms ITP): Kinetic Approach

“…The PMMA microcapsule particles have an excellent heat storage property without decreasing the latent heat of PCM (J/g‐PCM) by the shell, which often occurs in heat storage polymer microcapsule particles . In the following, we confirm that ms ITP of MMA in the absence of the PCM also gives only micrometer‐size PMMA particles without the byproduct of submicrometer‐size PMMA particles, which are formed by accompanying emulsion polymerization . When microsuspension conventional radical polymerization ( ms CRP) was carried out under nearly identical conditions except for the CHI 3 , about half amount of PMMA was formed as submicrometer‐size byproduct particles by accompanying emulsion polymerization.…”

“…Microsuspension polymerization must be basically carried out within micrometer‐size monomer droplets, in which hydrophobic initiator is previously dissolved. In actual, the ms CRP of hydrophobic monomer such as styrene proceeds therein and similar size of polymer particles as monomer droplets are prepared. Accordingly, the kinetic of ms CRP of hydrophobic monomer can be discussed like a bulk polymerization within the monomer droplets.…”

“…Figure 1 shows simulated time-conversion curves of bulk ITP of MMA and bulk CRP at 80 °C under the same recipe of the oil phase as the ms ITP carried out in the previous work. [17] Both polymerizations proceed at the same rate and complete for three hours. In the actual ms CRP, the polymerization proceeded faster because emulsion polymerization occurred at the same time.…”

“…Simulation for ITP of MMA based on the kinetic model was performed using PREDICI software from CiT GmbH (Rasfede, Germany) using kinetic coefficients shown in Table 1 , which are obtained from references shown in Table 2 . Concentrations of MMA, BPO and CHI 3 , which are, respectively, shown as [M], [I] and [CHI 3 ] in Table , used for the simulation are calculated from the recipe of the oil phase (except for PVA aqueous solution as the aqueous medium) of the ms ITP in the previous article: MMA, 5.0 g; BPO, 0.40 g; CHI 3 , 0.06 g (1 wt % PVA aqueous solution, 45.0 g).…”

“…[16] In the following, we confirm that ms ITP of MMA in the absence of the PCM also gives only micrometer-size PMMA particles without the byproduct of submicrometer-size PMMA particles, which are formed by accompanying emulsion polymerization. [17] When microsuspension conventional radical polymerization (ms CRP) was carried out under nearly identical conditions except for the CHI 3 , about half amount of PMMA was formed as submicrometer-size byproduct particles by accompanying emulsion polymerization. These results suggest a possibility to improve a long-standing problem in microsuspension polymerization of hydrophilic monomer by applying ITP in place of CRP.…”