Detailed investigation of the propagation rate of urethane acrylates

Christopher Barner-Kowollik, Francesca Bennet, Maria Schneider-Baumann, Dominik Voll, Thomas Rölle, Thomas Fäcke, Marc Stephan Weiser, Friedrich Karl Bruder, Thomas Junkers

Research output: Contribution to journalArticleResearchpeer-review

22 Citations (Scopus)

Abstract

Temperature dependent propagation rate coefficients, kp, are determined for four acrylate monomers containing a carbamate moiety via the pulsed laser polymerization-size exclusion chromatography (PLP-SEC) technique. Therefore, the Mark-Houwink-Kuhn-Sakurada coefficients K and a of the respective polymers were additionally determined via triple-detection SEC. The monomers under investigation were synthesized from hydroxyethyl acrylate, hydroxyl(iso)propyl acrylate as well as phenyl isocyanate and hexyl isocyanate, respectively, in all four possible combinations. For 2-(phenylcarbamoyloxy)ethyl acrylate (PhCEA) an activation energy of 14.3 kJ mol-1 and a frequency factor of A = 1.2 × 107 L·mol-1 s-1 are obtained for kp. The MHKS parameters for poly(PhCEA) are K = 8.3 × 10-5 dL g-1 and a = 0.677. For 2-(phenylcarbamoyloxy)isopropyl acrylate (PhCPA) an activation energy of 14.2 kJ mol-1 and a frequency factor of A = 4.9 × 10 6 L mol-1 s-1 are found for kp and the MHKS parameters for poly(PhCPA) read K = 10.3 × 10-5 dL g-1 and a = 0.657. The activation parameters of kp of 2-(hexylcarbamoyloxy)ethyl acrylate (HCEA) are EA = 13.3 kJ mol -1 and A = 6.6 × 106 L mol-1 s -1 with K = 36.0 × 10-5 dL g-1 and a = 0.552 for poly(HCEA). For 2-(hexylcarbamoyloxy)isopropyl acrylate (HCPA) E A is 14.1 kJ mol-1 and A = 6.6 × 106 L mol-1 s-1 with K = 26.0 × 10-5 dL g -1 and a = 0.587 for poly(HCPA). All rate measurements were performed in 1 M solutions in butyl acetate. The fast propagating nature and reduced activation energy of the monomers may be understood on the basis of the increased nucleophilicity that is induced by the carbamate functionality present in all monomers. Rate-increasing effects from solvent polarity and/or from H-bonding can, however, not be excluded and might also contribute to the observed high propagation rates.

Original languageEnglish
Pages (from-to)470-479
Number of pages10
JournalPolymer Chemistry
Volume1
Issue number4
DOIs
Publication statusPublished - 1 Jun 2010
Externally publishedYes

Cite this