Butyl methacrylate and 1‐octadecanethiol telomers were prepared by radical reactive extrusion. The main advantages of the use of this processing technique are that mass reactions can be conducted and continuous production is achieved within a reduced reaction time and a correct temperature control. Preliminary studies concerned the choice of the reactants for the telomerization reaction and the adaptation of the telomerization reaction to the reactive extrusion process. The transfer constant to C18H37SH was measured, and then experimental studies were conducted to verify that the hypothesis and approximations made for kinetic modeling are realistic. Particularly, it was shown that the use of relatively high chain‐transfer agent to monomer concentration ratio had no perceptible effect on the monomer conversion kinetic. These results allowed the choice of reactive extrusion conditions. Telomers were prepared using a laboratory co‐rotating twin‐screw extruder. The effect of reaction conditions (temperature, 1‐octadecanethiol to monomer concentration ratio) and of processing conditions (throughput, screw rotation speed) on the residence time distributions, molar mass and monomer conversions were examined. This study allowed the continuous synthesis of butyl methacrylate telomers having variable controlled molar masses and complete monomer conversion.
Screw profile used in reactive extrusion telomerization.
