Access to the β-scission rate coefficient in acrylate radical polymerization by careful scanning of pulse laser frequencies at elevated temperature

Anil B. Vir, Y. W. Marien, Paul H.M. Van Steenberge, Christopher Barner-Kowollik, Marie-Françoise Reyniers, Guy B. Marin, Dagmar R. D'Hooge

Research output: Contribution to journalArticleResearchpeer-review

13 Citations (Scopus)

Abstract

A novel method to estimate the β-scission rate coefficient (kβ) in radical polymerization of acrylates is introduced, provided that the backbiting and tertiary propagation rate coefficient have already been determined at sufficiently low temperatures at which β-scission is negligible (≪350 K). The method relies on the sensitivity of kβ upon a change of the pulse laser frequency (≪200 Hz) under isothermal pulsed laser polymerization (PLP) conditions in the temperature range between ca. 350 and 415 K, leading to a sufficient variation of the times scales of the radicals involved. These observations are not significantly influenced by macropropagation and thermal self-initiation, as respectively confirmed by in silico testing and experimental data. Solution inflection point data (e.g. solvent butyl propionate) are needed in the lower temperature range (350-410 K), whereas bulk inflection point data suffice in the higher temperature range (410-415 K). The proposed method leads to an estimated kβ value of (4.26 ± 1.8) × 102 s-1 at 413 K with bulk PLP data, suggesting a high propensity of macromonomer formation in acrylate polymerization under high temperature radical polymerization conditions, exceeding the previously suggested levels (kβ = 6 × 100-1.45 × 102 s-1).

Original languageEnglish
Pages (from-to)807-815
Number of pages9
JournalReaction Chemistry & Engineering
Volume3
Issue number5
DOIs
Publication statusPublished - 1 Oct 2018
Externally publishedYes

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