On kinetics of microemulsion copolymerization of butyl acrylate and acrylonitrile

Abstract

The oil‐in‐water microemulsion copolymerizations of butyl acrylate and acrylonitrile initiated by water (ammonium peroxodisulfate, AP)—and oil (dibenzoyl peroxide, DBP)—soluble radical initiators were investigated. Copolymerizations show two distinct nonstationary rate regions. The maximum rate of polymerization is found to be proportional to the 0.48th and 0.65th power of the AP and DBP concentration, respectively. The rate per particle is found to be proportional to the 0.05th and 0.2nd power of the AP and DBP concentration, respectively. The rate of polymerization decreases with increasing the acrylonitrile concentration. The number of particle increases with increasing conversion up to 50–70%. The number‐average molecular weight increases with conversion up to ca. 20% and then decreases. The number‐average molecular weights were found to decrease with increasing the concentration of both initiator and acrylonitrile. The experimental results were discussed in terms of the water‐phase polymerization, the chain‐transfer and radical desorption events, the particle nucleation during the whole polymerization, and recruiting monomer and emulsifier from the free monomer‐swollen emulsifier micelles. © 1996 John Wiley & Sons, Inc.

Effect of Copolymer Composition on the Dynamic Mechanical and Thermal Behaviour of Butyl Acrylate‐Acrylonitrile Copolymers

“…[33] The monomers used in the present work, butyl acrylate and acrylonitrile differ in relative water solubility (BuA ¼ 0.011 mol/l; AN ¼ 1.6 mol/l). [6] The acid comonomer, acrylic acid (AA) is still more soluble. There have been many reports [34,35] on the role of acrylic acid in emulsion polymerisation, dealing with its concentration, location and effect on the properties.…”

“…Landfester and co-workers [5] reported recently on the miniemulsion homopolymerisation of acrylonitrile to produce nanocrystals. The literature [6][7][8][9][10] reports mainly deal with emulsion copolymerisation with acrylates, styrene, butadiene etc. Understanding the copolymerisation behaviour was the main subject of many recent investigations.…”

“…Understanding the copolymerisation behaviour was the main subject of many recent investigations. Capek and co-workers [6] investigated in detail the particle nucleation behaviour in the emulsion copolymerisation of butyl acrylate and acrylonitrile. The effect of surfactant type and concentration on the particle nucleation behaviour was also investigated.…”

Microstructure, Kinetics, and Transport in Oil‐in‐Water Microemulsion Polymerizations

“…[47][48][49][50] Shi et al studied the four component microemulsion copolymerization of styrene and acrylonitrile with butanol as the cosurfactant. [47] Increasing the butanol concentration decreases the rate of polymerization and increases the particle size.…”

“…[50] Increasing the concentration of the more hydrophilic monomer decreases the rate of polymerization and the calculated concentration of radicals per particle, as well as the number-average molecular weight. Therefore, the authors conclude that the hydrophilic acrylonitrile monomer regulates the concentration of radicals in the particles, and the polymerization kinetics, by controlling the entry and exit events.…”