Dominique Charmot

Dithiocarbamates as universal reversible addition-fragmentation chain transfer agents

Control of the radical polymerization of acrylates, styrene and vinyl acetate has been achieved by using novel dithiocarbamates as reversible addition-fragmentation chain transfer agents. The key parameter for the control with N,N-disubstituted (A) or cyclic (B) dithiocarbamates was found to be the conjugation of the lone pair of electrons of the nitrogen atom with carbonyl or aromatic groups.

Seeded semibatch emulsion polymerization of butyl acrylate : Effect of the chain-transfer agent on the kinetics and structural properties

The effect of dodecane-1-thiol on the kinetics, gel fraction, level of branches, and sol molecular weight distribution of the seeded semibatch emulsion polymerization of n-butyl acrylate carried out at 75 °C was investigated. The gel fraction was strongly affected by the content of the chain-transfer agent (CTA). The sol weight-average molecular weights decreased with increasing CTA concentration, whereas no effect on the kinetics and the level of branches was observed. The experimental data were analyzed with a mathematical model of the process that was able to catch fairly well the effect of the process variable. In addition, adhesive tests were carried out to check the effect of the gel fraction on the adhesive properties.