Pulsed laser studies of cationic reactive surfactant radical propagation kinetics

Pulsed laser polymerization coupled with size exclusion chromatography (PLP-SEC) was implemented to study the micellar radical homopropagation kinetics of cationic surfmer, polycaprolactone choline iodide ester methacrylate (PCL(n)ChMA with n = 2 average polyester units), at concentrations of 5, 10, and 20 wt% in aqueous solutions at 25, 50, 70, and 85 degrees C. PCL(2)ChMA can propagate in both aqueous and compart-mentalized phases, with the relative importance of the two reaction loci changing with temperature. As the corresponding saturated macromonomer concentration, [M], inside the growing polymeric micelles cannot be easily determined, only the product of propagation rate coefficient (k(p)) and [M] are measured by PLP-SEC; at 25 degrees C, a minimum k(p) of 863 +/- 95 L mol(-1) s(-1) is estimated assuming bulk [M]. (Macro) monomer composition drifts for batch acrylamide (AM)/PCL(n)ChMA micellar copolymerizations in D2O at 50 degrees C are well represented by the apparent reactivity ratios r(AM) = 0.31 +/- 0.03 and r(PCL3ChMA) = 8.79 +/- 0.38. (C) 2017 Published by Elsevier Ltd.