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Interaction of Surfactant and Initiator Types in Emulsion Polymerisations: A Comparison of Ammonium Persulfate and Hydrogen Peroxide
Author(s) -
Boutti Salima,
Zafra Rocio Diez,
Graillat Christian,
McKenna Timothy F.
Publication year - 2005
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200500111
Subject(s) - chemistry , radical , hydrogen peroxide , pulmonary surfactant , emulsion polymerization , peroxide , radical polymerization , stabiliser , polymer chemistry , photochemistry , monomer , inorganic chemistry , organic chemistry , biochemistry , food science , polymer
Summary: In emulsion polymerisation all the components of the system have an influence on the nucleation mechanisms and colloidal stability, and therefore on the final particle size distribution (PSD). The impact of the nature of the initiator (charged radicals and electrically neutral radicals) and its interaction with the composition of the surfactant system and the radical flux on d p is studied in this paper. It was demonstrated that the influence of the nature of initiator on d p depends on the composition of the surfactant system. No influence of the nature of the initiator on N p (number of particles per litre) or the rate of reaction could be discerned when even trace amounts of anionic surfactant were present. But for surfactant‐free reactions or when non‐ionic surfactant (TN) was used as sole stabiliser, it was not possible to produce stable latex using electrically neutral radicals (in this case, hydroxyl radicals). Finally, the order of the semi‐continuous addition of ascorbic acid (AscA) and of hydrogen peroxide (HPO) was studied. As expected, a significant influence of the order of addition was observed in terms of the radical flux and reaction kinetics. It was demonstrated that one mole of AscA added to HPO provides more free radicals than are obtained when a mole of HPO is added to AscA.Overall conversion vs. reaction time.