Dispersion polymerization of MMA in supercritical CO2 stabilized by random copolymers of 1H,1H–perfluorooctyl methacrylate and 2‐(dimethylaminoethyl methacrylate) |
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| Authors: | Ha Soo Hwang Haldorai Yuvaraj Won Soo Kim Won‐Ki Lee Yeong‐Soon Gal Kwon Taek Lim |
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| Institution: | 1. Division of Image and Information Engineering, Pukyong National University, Busan 608‐739, Korea;2. Polymer Chemistry Laboratory, College of Engineering, Kyung Il University, Gyeongsang buk‐do, 712‐701, Korea |
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| Abstract: | A series of random copolymers, composed of 1H,1H‐perfluorooctyl methacrylate (FOMA) and 2‐dimethylaminoethyl methacrylate (DMAEMA) were prepared as stabilizers for the dispersion polymerization of methyl methacrylate in supercritical CO2 (scCO2). Free‐flowing, spherical poly(methyl methacrylate) (PMMA) particles were produced in high yield by the effective stabilization of poly(FOMA‐co‐DMAEMA) containing 34–67 w/w % (15–41 m/m %) FOMA structural units. Less stabilized but micron‐sized discrete particles could be obtained even with 25 w/w % (10 m/m %) FOMA stabilizer. The result showed that the composition of copolymeric stabilizers had a dramatic effect on the size and morphology of PMMA. The particle size was controllable with the surfactant concentration. The effect of the monomer concentration and the initial pressure on the polymerization was also investigated. The dry polymer powder obtained from dispersion polymerization could be redispersed to form stable aqueous latexes in an acidic buffered solution (pH = 2.1) by an electrostatic stabilization mechanism due to the ionization of DMAEMA units in the stabilizer. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1365–1375, 2008 |
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| Keywords: | amphiphiles ambidextrous surfactant colloids dispersion polymerization 2‐dimethylaminoethyl methacrylate PMMA radical polymerization random copolymer stabilization stabilizer supercritical CO2 surfactants |
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