Premium
The dispersion polymerization of unsaturated monomers initiated by the macromonomeric initiator
Author(s) -
Yildiz Ufuk
Publication year - 2002
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/1521-3900(200203)179:1<297::aid-masy297>3.0.co;2-x
Subject(s) - polymerization , styrene , dispersion polymerization , polymer chemistry , methyl methacrylate , monomer , dispersion (optics) , activation energy , copolymer , materials science , bulk polymerization , polymer , radical polymerization , chemistry , organic chemistry , physics , optics
The dispersion polymerizations of styrene (St) and methyl methacrylate (MMA) initiated by poly(oxyethylene) macroinimer (PEO‐MIM) in ethanol/water were investigated at 50, 60 and 80°C. The polymerisation rate vs. conversion dependence was described by with a maxim at the beginning of polymerisation. Polymerization was faster with MMA than with St. The limiting conversion was inversely proportional to temperature and was much more pronounced with St. The rate of polymerization increased with temperature. The overall initial activation energy increased with conversion and reached value ca. 25 kJ.mol −1 for MMA and 50 kJ.mol −1 for styrene at ca. 60% conversion. The particle size was observed to decrease with increasing the macroinimer concentration. The polymer dispersions were unstable and a large amount of coagulum appeared during the polymerisation especially in the styrene‐containing reaction system.