Emulsification in batch-emulsion polymerization of styrene and vinyl acetate: A reaction calorimetric study

Abstract

Dispersion of liquid-liquid systems is commonly applied in industrial processes such as extraction, suspension, and emulsion polymerization. This article describes the influence of the quality of emulsification on the course and outcome of a batch-emulsion polymerization of styrene and vinyl acetate. From visualization experiments and polymerizations in combination with reaction calorimetric studies, a critical impeller speed, N*, can accurately be determined for a particular reactor setup and a given recipe. The results show that styrene-water emulsions are more difficult to emulsify than vinyl acetate-water emulsions. In general, a large turbine impeller appears to be more effective in emulsifying monomer-water dispersions than a pitchedblade impeller. In addition, for vinyl acetate emulsion polymerization, the possibility of premixing the reaction mixture has been investigated.

Diffusion‐Controlled Particle Growth and its Effects on Nucleation in Stirred Emulsion Polymerisation Reactors

“…[2][3][4][5] This has been associated with a formation of a larger number of particles. [6][7][8] The effects of impeller speed and/or type on the rate of copolymerisation, molecular weights, [4,9] and particle size distribution [10] have been also reported.…”

Semibatch emulsion copolymerization of butyl acrylate and glycidyl methacrylate: Effect of operating variables

“…At 75 rpm, however, the monomer conversion highly decreased (seed stage). This is due to insufficient agitation speed to well emulsify the monomer; as a result, part of the monomer is separated from the emulsion leading to a decrease in the rate of monomer transport to the particles where polymerization is taking place 12. Such dissimilarities are also observed at feed and steady stages (Fig.…”

The effect of Co(II)‐mediated catalytic chain transfer on the emulsion polymerization kinetics of methyl methacrylate

“…All reactions are performed in a glass 1.2 dm 3 Mettler Toledo RC1 reactor equipped with an anchor impeller, temperature sensor, calibration heater, and sample loop. The RC1 program operated in isothermal mode, and all additions and sampling were performed manually 21, 22…”

“…The RC1 program operated in isothermal mode, and all additions and sampling were performed manually. 21,22 A catalyst stock solution was prepared: (i) by dissolving an accurate amount of COBF (close to 6 mg, 1.4 Â 10 À2 mmol) in MMA (40.0 mL). An initiator solution (ii) by dissolving an accurate amount of V50 in 10.0 mL water.…”