Semicontinuous emulsion copolymerization of styrene and butyl acrylate

Abstract

SynopsisSemicontinuous emulsion copolymerization of styrene and butyl acrylate with a constant rate of feed of monomer emulsion was investigated. The integral composition of the copolymer at the end of the feeding was different from the feed composition, and the difference was proportional to the monomer feeding rate. The closer the feed composition was to the composition at the azeotropic point, the lower was the sensitivity of the system to the feeding rate. At low feeding rates, the copolymerization proceeded at conversions of about 90-95%, and the composition of the copolymer was practically equal to that of the monomer feed. The reactivity ratios determined under these conditions were probably influenced by diffusion inside the growing polymermonomer particles.

Viscoelastic behaviour of butyl acrylate/styrene/2-hydroxyethyl methacrylate/acrylic acid latices thickened with associative thickeners

“…Polymerisations were carried out in a glass reactor under nitrogen atmosphere using an ammonium peroxydisulphate-sodium disulphite initiator system and Disponil AES 60 (sodium polyglycol alkylaryl ether sulphate, Henkel, Germany) in an amount of 2 wt% of the active component (relative to the monomers) as an emulsifier. Such process guarantees statistical composition of the dispersed copolymer particles [12][13][14].…”

A kinetic study of free radical copolymerization of styrene/butyl acrylate

“…More recently an extensive study of the S/BA system describing both the reactivity ratios and the low conversion copolymerization rate has been carried out by Kaszas et al 4,5) Dubé et al 6,7) have developed a mechanistic model in order to analyze the bulk copolymerization of this system in the full range of conversion. Emulsion copolymerization kinetics data for this system have also been described [8][9][10][11] . In recent years, it has been observed in many copolymerization systems that, while the Mayo-Lewis terminal model (MLTM) can describe properly the copolymer composition as a function of the molar monomer fraction in the feed 12) , it fails to predict the copolymerization rate.…”

Mechanical Characterization of Polymeric Films Based on Copolymers of Styrene and Butyl Acrylate Obtained by Heterogeneous Polymerization in Semicontinuous

“…According to the values of the reactivity ratio of the monomers reported for this system 8 (rSt = 1,006 and rBA = 0,232), a random copolymer is obtained with a large proportion of St in the copolymer. However, in the semicontinuous process, at low monomer addition rates, a random copolymer is obtained with a composition similar to the feed ratio 9 .…”

“…However, in the semi-continuous process, at low monomer addition rates, a random copolymer is obtained with a composition similar to the feed ratio 9 .…”