The effect of solvent on the homo-propagation rate coefficients of styrene and methyl methacrylate

Michael D. Zammit, Thomas P. Davis, Gary D. Willett, Kenneth F. O'Driscoll

Research output: Contribution to journalArticleResearchpeer-review

83 Citations (Scopus)

Abstract

The free radical propagation rate coefficients of both Methyl Methacrylate (MMA) and Styrene (STY) have been measured using Pulsed-Laser Polymerization. The effect of solvents on the propagation rate coefficient, kp, is reported for several solvents, namely, bromobenzene, chlorobenzene, dimethyl sulphoxide, diethyl malonate, diethyl phthalate, benzonitrile, and benzyl alcohol, at 26.5°C. This preliminary data indicated that benzyl alcohol (BzA) had a large effect on the MMA propagation reaction. As earlier work indicated that N-methyl pyrrolidinone (NMP) would also have a large effect on the kp of MMA, Arrhenius parameters were evaluated for both MMA and STY at two different concentrations of monomer in BzA and NMP. BzA had a significant effect (at 95% confidence) increasing both the activation energy (Ea) and the preexponential factor (A) for MMA and STY. In NMP, a similar trend is observed for MMA polymerization; however, while a solvent effect on STY was observed, the effect on Ea and A was too small to discern with confidence. A series of additional experiments was performed to evaluate the influence of camphorsulfonic acid (CSA) as an additive in STY polymerization. There was no effect of CSA on kp, confirming that the strong effect CSA has on "living" radical polymerization of styrene does not originate from complexation leading to an accelerated propagation step but rather by altering the ratio of active-to-dormant chains in the reaction.

Original languageEnglish
Pages (from-to)2311-2321
Number of pages11
JournalJournal of Polymer Science, Part A: Polymer Chemistry
Volume35
Issue number11
DOIs
Publication statusPublished - 1 Jan 1997
Externally publishedYes

Keywords

  • "Living" free radical
  • Benzyl alcohol
  • Methyl methacrylate
  • N-methyl pyrrolidinone
  • Propagation rate coefficient
  • Pulsed-laser polymerization
  • Solvent effects
  • Styrene

Cite this