Premium
Monomer‐to‐water ratios as a tool in controlling emulsion copolymer composition: The methyl acrylate–indene system
Author(s) -
Noël Lilian F. J.,
Van Zon Jan M. A. M.,
German Anton L.
Publication year - 1994
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1994.070511213
Subject(s) - monomer , copolymer , polymer chemistry , reactivity (psychology) , methyl acrylate , acrylate , chemistry , emulsion , mole fraction , chemical engineering , materials science , organic chemistry , polymer , medicine , alternative medicine , pathology , engineering
Abstract A drifting copolymer composition as a function of conversion is an aspect typical of copolymerization. Reducing this so‐called composition drift in batch copolymerizations will lead to a decrease in chemical heterogeneity of the copolymers formed. For monomer systems in which the more water‐soluble monomer is also the more reactive one, theory predicts that composition drift in emulsion copolymerization can be reduced or even minimized by optimizing the monomer‐to‐water ratio. The monomer combination methyl acrylate–indene (MA–Ind) meets the requirements needed to minimize composition drift in batch emulsion copolymerization. Therefore, this monomer combination is chosen as a model monomer system in order to verify this theoretical prediction. Reactivity ratios needed for model predictions have been determined by low conversion bulk polymerization, resulting in r MA = 0.92 ± 0.16 and r Ind = 0.086 ± 0.025. Furthermore, emulsion copolymerization reactions at the same monomer mole fraction are performed at different monomer to water ratios. From the good agreement between experiments and theoretical predictions for MA–Ind, it was concluded that control and even minimization of composition drift in batch emulsion copolymerization for monomer systems in which the more water‐soluble monomer is also the more reactive one is indeed possible by changing the initial monomer‐to‐water ratio of the reaction mixture provided that the reactivity ratios of both monomers are not too far from unity. © 1994 John Wiley & Sons, Inc.