Cationic photopolymerization of vinyl ether systems: influence of the presence of hydrogen donor additives

Several alcohols (il-butanol, 2-propanol, 2-phenyl-2-propanol) and water we re added to diethylene-glycol-divinyl-ether (DVE2) or triethylene-glycol-di vinyl-ether (DVE3) in order to investigate their influence on the cationic photopolymerization in the presence of triarilsulfonium hexafluorophosfate as photoinitiator. Until 5% w/w concentration, the alcohols do not show any influence on the rate of polymerization, but they increase the final doubl e bond conversion indicating a plasticization effect. Water causes a decrea se of the rate of polymerization and an increase of the final double bond c onversion. DSC and DR-ITA analyses show that the presence of the additives decreases the T-g of the UV-cured products. The results are interpreted on the basis of a chain transfer reaction involving -OH groups. (C) 1999 Elsev ier Science Ltd. All rights reserved.