title: Kilohertz Pulsed-Laser-Polymerization: Simultaneous Determination of Backbiting, Secondary, and Tertiary Radical Propagation Rate Coefficients for tert-Butyl Acrylate.
abstract: For the first time, a 1000 Hz pulse laser has been applied to determine detailed kinetic rate coefficients from pulsed laser polymerization-size exclusion chromatography experiments. For the monomer tert-butyl acrylate, apparent propagation rate coefficients kp (app) have been determined in the temperature range of 0-80 °C. kp (app) in the range of few hundreds to close to 50 000 L·mol(-1) ·s(-1) are determined for low and high pulse frequencies, respectively. The apparent propagation coefficients show a distinct pulse-frequency dependency, which follows an S-shape curve. From these curves, rate coefficients for secondary radial propagation (kp (SPR) ), backbiting (kbb ), midchain radical propagation (kp (tert) ), and the (residual) effective propagation rate (kp (eff) ) can be deduced via a herein proposed simple Predici fitting procedure. For kp (SPR) , the activation energy is determined to be (17.9 ± 0.6) kJ·mol(-1) in excellent agreement with literature data. For kbb , an activation energy of (25.9 ± 2.2) kJ·mol(-1) is deduced.
authors.affiliation: Polymer Reaction Design Group, Institute for Materials Research (IMO), Universiteit Hasselt, Martelarenlaan 42, B-3500, Hasselt, Belgium.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Wenn
authors.affiliation: Polymer Reaction Design Group, Institute for Materials Research (IMO), Universiteit Hasselt, Martelarenlaan 42, B-3500, Hasselt, Belgium.|IMEC Associated Lab IMOMEC, Wetenschapspark 1, B-3590, Diepenbeek, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Junkers
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D007700:Kinetics; D007834:Lasers; D055668:Photochemical Processes
chemical_list: D000179:Acrylates; C522411:tert-butyl acrylate
keywords: acrylates; backbiting; pulsed laser polymerization; radical polymerization