The Effects of Abstractable Hydrogen in Radical Photopolymerization of Maleate/Vinyl Ether Monomers Studied with EPR and Photo-RTIR

作者：Haraldsson Tommy; Johansson Mats^*; Hult Anders

来源：Journal of Polymer Science Part A: Polymer Chemistry , 2010, 48(13): 2810-2816.

DOI：10.1002/pola.24050

• copolymerization
• ESR/EPR
• kinetics (polym.)
• maleate
• vinyl ether

In this contribution, the influence of abstractable hydrogen on the kinetics of photopolymerized vinyl ether/maleate monomer formulations is reported. The effects of chain transfer on the polymerization rate were studied with photo real-time Infra Red (IR) for formulations composed of equimolar amounts of diethyl (DEMA) and three different vinyl ethers; methyl hexyl vinyl ether where the abstractable hydrogens adjacent to the vinyl functionality have been replaced with methyl groups, ethyl hexyl vinyl ether (EHVE) which has two easily abstractable alpha-hydrogens and triethylene glycol methyl vinyl ether (TEGMVE), which has several abstractable hydrogens. Four conclusions are drawn from these studies: (i) the vinyl ether/maleate kinetics differs significantly from the classical expression R(p) = KI(0.5), with recorded exponential factors of 0.84 +/- 0.04 in the absence of easily abstractable hydrogens; (ii) the presence of abstractable hydrogens significantly changes the kinetics of vinyl ether/maleate polymerizations with recorded exponential factors of 0.55 +/- 0.04 for EHVE/DEMA and 0.70 +/- 0.04 for TEGMVE/DEMA; (iii) the presence of easily abstractable hydrogens leads to a preferential consumption of maleates; and (iv) electron paramagnetic resonance studies show that vinyloxy-like radicals constitute the majority of the radicals in the systems with easily abstractable hydrogens.

• 出版日期2010-7-1