Mise au point d'un procédé continu de fabrication de polyméthacrylate de méthyle syndiotactique par polymérisation anionique : eétude cinétique et conception d'un dispositif original de micromélange

Abstract : The anionic polymerisation of methylmethacrylate has been studied in order to contribute to the development of a new process for the syntheses of syndiotactic polymethylmethacrylate. First, a kinetic study of the polymerisation initiated by 1,1-diphenylhexyllthium in the presence of a lithium alkoxyalkoxyde as ligand has been performed between – 40 C and + 40 C in a tubular reactor in which the residence times are in the range of 7ms to 3s. The effects of initiator concentration, temperature, polarity of the media, amount of ligand and its nature have been pointed out. In all cases, the kinetic is extremely fast. The living character of the polymerisation is kept for temperature less or equal to 0 C. Taking into account, the results of the kinetic study, a particular attention should be focused on micromixing considerations for the scale-up. A test chemical reaction was used to characterise the efficiency of the mixers developed in this work. Micromixing times has been calculated from the incorporation model and values less than milliseconds were found. During trials on a pilot plant, low polydisperse PMMA have been obtained for the first time at 30 % solid contains. It has been shown that the lowest micromixing times lead to the lowest polydispersity. Nevertheless, because of the highly viscous media, tangential jets micromixers, lead to plugging when solid contains higher than 30 % are desired. A solution of this problem based on free jets impact is proposed. The very first result are significant and open interesting doors for future developments of this device
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Theses
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http://docnum.univ-lorraine.fr/prive/INPL_T_1997_MARCARIAN_X.pdf
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https://hal.univ-lorraine.fr/tel-01752325
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Submitted on : Thursday, March 29, 2018 - 1:41:01 PM
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Xavier Marcarian. Mise au point d'un procédé continu de fabrication de polyméthacrylate de méthyle syndiotactique par polymérisation anionique : eétude cinétique et conception d'un dispositif original de micromélange. Autre. Institut National Polytechnique de Lorraine, 1997. Français. ⟨NNT : 1997INPL127N⟩. ⟨tel-01752325⟩

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