Ab initio based kinetic Monte Carlo analysis to unravel the propagation kinetics in vinyl acetate pulsed laser polymerization

Abstract

The radical propagation kinetics of vinyl acetate (VAc) in pulsed laser polymerization (PLP) is studied by combining ab initio calculated rate coefficients for propagation of head, tail and mid-chain radicals, and backbiting reactions with kinetic Monte Carlo modeling of PLP spectra. The intriguing laser pulse frequency dependency of the propagation kinetics is shown to be mainly caused by the formation of stabilized mid-chain radicals via backbiting of tail radicals, originating from head-to-head propagation. These mid-chain radicals are approximately 35 times less reactive towards propagation at 323 K which, in agreement with experimental observations, results in a 15% increase of the observed propagation rate coefficient if the laser pulse frequency is increased from low (25-100 s −1

How to Fight Kinetics in Complex Radical Polymerization Processes: Theoretical Case Study of Poly(divinyl ether‐alt‐maleic anhydride)

“…Diffusion factors were taken into account as some addition reactions in the DVEMAN copolymerization were found to be low barrier . Diffusion effects were explored via the coupled encounter pair model that was found to be applicable for rough estimation of diffusion in polymerization processes . The coupled encounter pair model considers that, in order for chemical equilibrium to be established, a series of resistances need to be overcome, both in the forward and in the backward direction.…”

“…Recent progress in different modeling techniques amplified with development of computational resources and methods and in conjunction with experimental field advancements enabled theoretical investigation of polymerization on different scale, for example, polymer molecular scale or micro‐, meso‐, and macroscales . Application of the modeling methods to the investigation of regulation factors of structural and stereoisomerism of DVEMAN is a novel area that can give necessary theoretical ground for applied research.…”

Preparation and Characterization of Soap-Free Vinyl Acetate/Butyl Acrylate Copolymer Latex

“…Polyvinyl acetate emulsion (PVAc) is a high molecular polymer synthesized by free radical polymerization, which is widely used in industries such as light industry, textile and wood processing [1][2][3]. Generally, the polyvinyl acetate homopolymer has poor water resistance and weather resistance, and the stability of the emulsion is also poor without a protective colloid, so it is often modified with certain methods to improve emulsion performance [4][5][6]. Butyl acrylate (BA) has a long-chain alkyl group which provides a certain steric hindrance.…”

Determination of Head‐Addition Incidence of Methyl Acrylate and Temperature Dependence in Radical Polymerization by Coupling Reversible Addition‐Fragmentation Chain Transfer Block Polymerization Derivatization and Gradient Polymer Elution Chromatography

“…[ 1–5 ] So “less activated monomers” show higher head‐addition incidence, such as vinyl acetate (VAc), N ‐vinylpyrrolidone, and fluorinated monomers. [ 2,6–14 ] Meanwhile, “more activated monomers” (MAM) with higher conjugated side groups possess low head‐addition incidence, such as styrene, methacrylate, and acrylate. [ 14 ]…”