Kinetics of the batch cationic emulsion polymerization of styrene: A comparative study with the anionic case

Authors

  • Jose Ramos,

    1. Servicio de Caracterización de Polímeros: Microscopia, Facultad de Ciencias Químicas,Universidad del País Vasco/EHU, Apdo. 1072, Donostia-San Sebastián 20080, Spain
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  • Álvaro Costoyas,

    1. Institute for Polymer Materials Polymat and Grupo de Ingeniería Química, Facultad de Ciencias Químicas,Universidad del País Vasco/EHU, Apdo. 1072, Donostia-San Sebastián 20080, Spain
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  • Jacqueline Forcada

    Corresponding author
    1. Institute for Polymer Materials Polymat and Grupo de Ingeniería Química, Facultad de Ciencias Químicas,Universidad del País Vasco/EHU, Apdo. 1072, Donostia-San Sebastián 20080, Spain
    • Institute for Polymer Materials Polymat and Grupo de Ingeniería Química, Facultad de Ciencias Químicas,Universidad del País Vasco/EHU, Apdo. 1072, Donostia-San Sebastián 20080, Spain
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Abstract

An in-depth study on the kinetics of the cationic emulsion polymerization of styrene in a batch reactor is presented. This study is focused on the effect of the amount of the cationic surfactant dodecyltrimethylammonium bromide (DTAB), using two different cationic initiators: 2,2′-azobisisobutyramidine dihydrochloride (AIBA), 2,2′-azobis (N,N′-dimethyleneisobutyramidine) dihydrochloride (ADIBA), on kinetics and colloidal features such as conversion, number of particles, number average of radicals per particle, mean particle diameter, and particle size distribution (PSD) of the polystyrene latices obtained by emulsion polymerization in a batch reactor. Furthermore, the results of the cationic emulsion polymerization were compared with its homologous anionic case. Using DTAB as cationic surfactant an expected increase in the total rate of polymerization was observed when the DTAB concentration increased. However, the total number of particles increased much more than in the anionic system. On the other hand, a dependence on the particle size of the rate of polymerization per particle together with the average number of radicals per particle was found. These differences between cationic and anionic emulsion polymerizations were explained taking into account the limited particle coagulation observed with cationic surfactants, and the high rate of radical formation of cationic initiators. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4461–4478, 2006

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