Modified frontal polymerization of poly(methyl methacrylate) |
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Authors: | Armando García Villegas Miguel A Ocampo Enrique Saldivar‐Guerra Beatriz García‐Gaitán Eduardo Vivaldo‐Lima Gabriel Luna‐Barcenas |
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Affiliation: | 1. Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Unidad Querétaro, Querétaro, QRO 76230, México;2. Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, QRO 76230, México;3. Centro de Investigación en Química Aplicada, Boulevard Enrique Reyna Hermosillo 140, Saltillo, Coahuila, México;4. División de Estudios de Posgrado e Investigación, Instituto Tecnológico de Toluca, Metepec, Estado de México 52140, México;5. Departamento de Ingenieria Quimica, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, 04510, Mexico, DF, Mexico |
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Abstract: | In this work, we propose a modified frontal polymerization method to build a uniform reaction front by gradually immersing the reacting mixture in a thermal bath. This scheme allows uniform materials to be obtained with nearly constant molecular weights and polydispersities and a low residual monomer concentration. A comparative study of the molecular weight distributions of poly(methyl methacrylate)s obtained by bulk polymerization, frontal polymerization, and frontal polymerization with the proposed gradual immersion is presented. Samples obtained by these methods show that materials obtained by bulk polymerization and by frontal polymerization are less uniform than those obtained by frontal polymerization with gradual immersion in a thermal bath. The obtained uniformity is directly related to a stabilizing effect of the reaction front by the gradual immersion of the reactor in a constant‐temperature bath and to a reduction in the reaction rate promoted by a moderate transfer agent concentration. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 |
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Keywords: | degree of polymerization (DP) gel permeation chromatography (GPC) molecular weight distribution/molar radical polymerization synthesis |
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