Experimental and modeling studies on styrene–butyl methacrylate copolymerization reaction

Joshi, M. V.; Mukesh, D.

doi:10.1002/app.1993.070500110

Cited by 7 publications

(5 citation statements)

References 6 publications

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“…Optical microscopy of liquid samples taken just before and after the foaming shows a sudden change in the characteristics. The former sample shows the presence of a large number of liquid droplets, and the latter the absence of them and the appearance of solid fine polymer particles . This observation from the liquid side once again confirms the sudden rise in polymerization rate at about 90 min in this reactor.…”

Section: Kinetic Studiessupporting

confidence: 75%

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Scale-Up Studies on Styrene−Butyl Methacrylate Copolymerization Reaction

Mukesh¹,

Joshi²,

Durve³

et al. 1997

Org. Process Res. Dev.

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The scale-up of the radical-initiated copolymerization of styrene with butyl methacrylate is studied here. The reaction is scaled up from 3 to 100 L scale. The problems encountered during the scale-up are agglomeration, foaming, and material loss. The techniques employed to overcome these problems are discussed in detail. Kinetic studies indicate that the reaction exhibits autoacceleration behaviour, with induction time varying with reactor size. The effects of initiator concentration and reactor size on the molecular weight and melt flow index of the final sample are also studied.

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Section: Kinetic Studiessupporting

confidence: 75%

“…Mole fraction of monomer in the feed is estimated by analyzing the liquid sample by GLC. The mole fraction of monomer in the polymer is estimated by analyzing the polymer sample by 1 H NMR …”

Section: Monomer Reactivity Ratiosmentioning

confidence: 99%

Scale-Up Studies on Styrene−Butyl Methacrylate Copolymerization Reaction

Mukesh¹,

Joshi²,

Durve³

et al. 1997

Org. Process Res. Dev.

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“…The conversion X M at the onset of autoacceleration increases with increasing polymerization temperature, in accordance with published data. 20,27 Kinetic model It is necessary to find a kinetic model that fits the conversion vs time curves, and shows the same derivatives (dX/dt) and (d 2 X/dt 2 ) as the experimental results (Figure 3).…”

Section: Methodsmentioning

confidence: 99%

A new approach for the kinetic modeling of free radical bulk polymerization of styrene

Bera

Radičević

Stoiljkovic

et al. 2011

Polym J

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The kinetics of styrene-free radical bulk polymerization was studied by differential scanning calorimetry (DSC). The data obtained from DSC thermograms were used to model and predict the autoacceleration during styrene polymerization and to understand how it is influenced by temperature. The experimental data were well described by the estimated kinetic model. The model included two processes (the first-order reaction and autoacceleration), because they occur simultaneously as two parallel reactions rather than being strictly separated. It was found that the autoacceleration activation energy is approximately four times lower than the energy of the first-order reaction. In addition, the first-order reaction followed by the autoacceleration of the styrene-free radical bulk polymerization occurs simultaneously only between 41.7 and 110.5 1C. Keywords: autoacceleration; differential scanning calorimetry; polymerization kinetics; polystyrene; styrene-free radical bulk polymerization INTRODUCTION It is well known that the free radical bulk polymerization of vinyl monomers (derivates of acrylic and methacrylic acids, vinyl acetate, styrene, ethylene and so on) is characterized by the autoacceleration phenomenon. 1-3 The free radical polymerization of these monomers can be explained by classical theory up to definite conversion. After that conversion, autoacceleration of polymerization occurs. The onset of autoacceleration is the moment when the polymerization rate departs from the value anticipated by the classical theory of free radical polymerization. [3][4][5][6][7] The onset and the intensity of autoacceleration are determined by the type of monomer, initiator concentration, temperature and other reaction conditions. Ebdon and Hunt 3 used differential scanning calorimetry (DSC) to follow the course of free radical bulk polymerization of styrene and concluded that autoacceleration is less pronounced at 90 1C than at 80 1C and is absent at 100 1C and above. Autoacceleration appeared at about 2% conversion of styrene polymerized at 20 1C for 252 days in the presence of 2,2¢-azobisisobutyronitrile. 8 To explain this autoacceleration, an equation was applied to the kinetic data obtained under the condition of predominant transfer to the monomer. It was concluded that polymer molecules may move by repetition and the mobility of segments decreases with decrease of free volume. 8 Comparisons of the results obtained for styrene-free radical bulk polymerization with model predictions have quantified the dependence of the gel effect strength on the predominance of chain transfer events. 9 Cioffi et al. 10 performed a rheokinetic study of the bulk-free radical polymerization of styrene with a helical barrel rheometer. The rheokinetic measurements show that autoacceleration in the free radical polymerization of styrene can be reduced when the polymer-

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“…Leakage flows cause interaction between the chambers. The real volumetric throughput is therefore given by: (2) Since these kinds of extruders are fed starved, a partially filled zone arises apart from a fully filled zone before the die. The length of the fully filled zone is mainly determined by the pressure needed to overcome the die resistance and the geometry of the screws (9).…”

Section: The Counter-rotating Twin-screw Extrudermentioning

confidence: 99%

The working domain in reactive extrusion. Part I: The effect of the polymer melt viscosity

Goot¹,

Hettema²,

Janssen³

1997

Polymer Engineering & Sci

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This article describes the radical copolymerization of styrene (St) and n‐butyl‐methacrylate (BMA) in a counter‐rotating twin‐screw extruder. In order to investigate the effect of the polymer melt viscosity on the working domain in reactive extrusion, the copolymer was crosslinked with different amounts of divinylbenzene (DVB). Crosslinking of the polymer resulted in a higher polymer melt viscosity. It was demonstrated that not only the product properties but also the process characteristics were strongly influenced by the addition of divinylbenzene to the reaction mixture. The product properties changed as expected: more crosslink agent led to a higher molecular weight or an increase in gel fraction, and a much higher melt viscosity of the polymer. Besides these effects on the product properties, the addition of DVB resulted in a more stable process, leading to an enlarged working domain.

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Experimental and modeling studies on styrene–butyl methacrylate copolymerization reaction

Cited by 7 publications

References 6 publications

Scale-Up Studies on Styrene−Butyl Methacrylate Copolymerization Reaction

Scale-Up Studies on Styrene−Butyl Methacrylate Copolymerization Reaction

A new approach for the kinetic modeling of free radical bulk polymerization of styrene

The working domain in reactive extrusion. Part I: The effect of the polymer melt viscosity

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