SEARCH

SEARCH BY CITATION

Keywords:

  • CalB;
  • enzymatic polycondensation;
  • enzymes;
  • films;
  • networks;
  • photopolymerization;
  • polycondensation;
  • polyesters;
  • polyester films;
  • thermoset;
  • thiol-ene;
  • UV curing

Abstract

An enzymatic one-pot route in bulk was used to synthesize tetraallyl ether (tAE) functional oligomers based on divinyl adipate, 1,4-butanediol and trimethylolpropane diallyl ether. By using lipase B from Candida antarctica as catalyst and varying the stoichiometric ratio of monomers, it was possible to reach targeted molecular weights (from 1300 to 3300 g mol−1) of allyl-ether functional polyesters. The enzyme catalyzed reaction reached completion (>98% conversion based on all monomers) within 24 h at 60 °C, under reduced pressure (72 mbar) resulting in ∼90% yield after filtration. The tAE-functional oligoesters were photopolymerized, without any purification other than removal of the enzyme by filtration, with thiol functional monomers (dithiol, tetrathiol) in a 1:1 ratio thiol-ene reaction. The photo-initiator, 2,2-dimethoxy-2-phenylacetophenone, was used to improve the rate of reaction under UV light. High conversions (96–99% within detection limits) were found for all thiol-ene films as determined by FT-Raman spectroscopy. The tAE-functional oligoesters were characterized by NMR, MALDI, and SEC. The UV-cured homopolymerized films and the thiol-ene films properties were characterized utilizing DSC and DMTA. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010