Dispersion copolymerization of methyl methacrylate and acrylic acid in polar media: effects of reaction parameters on the particle size and size distribution of the copolymer microspheres

• Published in: Polymer international Vol. 52; no. 5; pp. 819 - 826
• Main Authors: Huang, Jin-Xia, Yuan, Xiao-Ya, Yu, Xiang-Lin, Zhang, Hong-Tao
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.05.2003; Wiley
• Subjects: acrylic acid; Applied sciences; Copolymerization; crosslinked functional microsphere; dispersion copolymerization; Exact sciences and technology; methyl methacrylate; Organic polymers; Physicochemistry of polymers; Preparation, kinetics, thermodynamics, mechanism and catalysts; crosslinked functional microsphere; Acrylic acid copolymer; Particle size; Microsphere; Polar solvent; Experimental study; Methyl methacrylate copolymer; dispersion copolymerization; Crosslinked copolymer; Structure processing relationship; methyl methacrylate; Particle size distribution; Pyrrolidone(vinyl) polymer; Medium effect; Dispersion polymerization; Methacrylate copolymer; acrylic acid; Radical copolymerization
• ISSN: 0959-8103; 1097-0126
• DOI: 10.1002/pi.1177

Micron‐size functional crosslinked poly(methyl methacrylate) (PMMA) particles with narrow size distribution in the range of 1∼5 µm were prepared by dispersion copolymerization in polar media with poly(N‐vinylpyrrolidone)(PVP) as steric stabilizer, 2,2′‐azobisisobutyronitrile(AIBN) as initiator and ethylene glycol dimethylacrylate (EGDMA) as crosslinking agent. The effects of functional comonomer acrylic acid (AA) concentration, contents in AIBN, EGDMA and PVP, media polarity as well as reaction temperature on the particle size and size distribution were investigated. Particle size initially increased, and then decreased with increasing AA concentration in the range of 0.7∼3.5 mol l−1, having a maximum of 5.01 µm at the concentration of 2.1 mol l−1, while size distribution became broader. This was regarded as the result of different roles of PAA in the process. Particle size increased with decreasing media polarity and stabilizer concentration, and with increasing initiator concentration and reaction temperature. The resulting particle shapes were observed by transmission electron microscopy and the presence of carboxyl groups on the surface of the particles was confirmed by Fourier‐transform infrared spectroscopy. Copyright © 2003 Society of Chemical Industry