Emulsion Polymerization of MMA employing a Chain Transfer Agent of Low Environmental Impact: Iso-octyl-3-mercaptopropionat

RONCO, LUDMILA I.; MINARI, ROQUE J.; CIAN, LORENA; VEGA, JORGE R.; GUGLIOTTA, LUIS M.

THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING

JOHN WILEY & SONS INC

Año: 2013 vol. 91 p. 599 - 605

0008-4034

The unseeded batch-emulsion polymerization of methyl methacrylate (MMA) was investigated, including the chain transfer agent iso-octyl 3-mercaptopropionate (iOMP) which exhibits a low environmental impact. The comercial iOMP is a mixture of over 10 isomers that proved to adequately control the molecular weights of poly(methyl methacrylate) with a decreasing evolution of both the number? and the weight? average molecular weights along the reactions. The iOMP also diminishes the polymerization rate and increases the particle number, as a consequence of: i) the lower reactivity of the iOMP radicals with respect to the MMA-ended radicals; and ii) the desorption of the iOMP radicals from the polymer particles towards the aqueous phase. Experimental results were interpreted with the help of a first principle mathematical model.