293*

Emulsion Copolymerization Modellingto Simultaneously Optimize SeveralProperties

S i l v eÁ r e M A S S E B E U F ,

h r i s t i a n F O N T E I X

F e r n a n d P L A

Laboratoire des Sciences du GeÂnie Chimique ± U.P.R. C.N.R.S. 6811,E.N.S.I.C., 1 rue Grandville, B.P. 451, 54001 Nancy Cedex, France

Products obtained by emulsion copolymerization are characterizedby some properties that have to be optimized for a given application.The aim of this paper is to show a methodological approach to si-multaneously optimize several properties of a copolymer. A batchemulsion copolymerization of styrene and alpha-methylstyrene isstudied. A tendency model is proposed to predict the main charac-teristics of the copolymer. The coupling of this simulator with amulticriteria optimization procedure allows to determine thebest working conditions to simultaneously obtain several desiredvalues of properties.

294*

Butadiene Free Radical Polymerizationwith Hydrogen Peroxide

P . D e F i l i p p i s

C . G i a v a r i n i

R . S i l l a

Department of Chemical Engineering, University of Rome ªLaSapienzaº, Via Eudossiana 18, 00184 Rome, Italy

Free radical polymerization of butadiene in a solution of ethanol asa solvent and in the presence of hydrogen peroxide as an initiatorwas studied. Batch polymerization occurs in the liquid phase atabout 120 �C. Because of the reactive compounds present andthe relatively high temperature used, side reactions such as alco-hol oxidation, are always possible. The polymerization reaction wasstudied using a high pressure calorimeter. The effect of the reactiontemperature and the presence of impurities on the reaction courseand the polymer characteristics were investigated. Most impor-tantly the presence of organic acids and/or ionic iron must beavoided. Recycle of unreacted reagents must be done carefullyto avoid the build-up of these impurities.

295*

Modeling of Kinetics and PolymerComposition of the N-Oxyle-Con-trolled Free Radical Polymerizationup to High Conversion

M a r c o D r a c h e

G u d r u n S c h m i d t - N a a k e

TU Clausthal, Institut fuÈ r Technische Chemie, Erzstraûe 18,38678 Clausthal-Zellerfeld, Germany

A model of copolymerization for the simulation of experimentaldata is introduced for the controlled free-radical copolymerizationof styrene with n-butyl methacrylate, which is started with diben-zoyl peroxide and 2,2,6,6-tetramethylpiperidine-N-oxyle (TEM-PO).

For the copolymerization the main termination reactionof the living free-radical chains is assumed to be a hydrogen-trans-fer-reaction generated by an elimination of a hydrogen atom fromthe methyl group of the chain-end of the n-butyl methacrylate ra-dical followed by its transfer to a free radical of TEMPO.

To come to a better understanding of the copolymeriza-tion reaction the calculation of the detailed product composition ofthe generated copolymers by variation of the comonomer mixturetogether with an additional acceleration of the reaction by an initia-tor is of great significance.

296*

Modeling of Thermal andConcentration Fields in TurbulentFlows with Fast Chemical Reactions

V . A . K a m i n s k y

A . Y a . F e d o r o v

A . B . R a b i n o v i c h

Karpov Institute of Physical Chemistry, Moscow, Russia; E-mail:kamin@cc.nifhi.ac.ru

Modeling of fast chemical reactions under the conditions of turbu-lent mixing is considered. The problems of modeling turbulent

Figure.Ethyl acetate reactive system at 1 atm. Filled triangles de-note azeotropes. The brackets are for boiling points in Celsi-us degrees. The hatched surface and the dotted line repre-sent reaction equilibrium in the original space and in theprojected space.

681R e a c t i o n E n g i n e e r i n gChemie Ingenieur Technik (73) 6 I 2001