Copolymerization Mechanism of Photoinitiator Free Thiol-Vinyl Acrylate Systems
Polymers and High Performance Materials
The photoinitiator-free copolymerization of trifunctional thiol/vinyl acrylate mixtures as a function of thiol content has been investigated using real-time FTIR in the presence and absence of oxygen. Even without external photoinitiators, the thiol/vinyl acrylate mixtures polymerize rapidly. The addition of a multifunctional thiol to vinyl acrylate results in the conversion of the vinyl double bond of vinyl acrylate due to the preferential addition of the thiyl radical to the vinyl double bond. Both the chain transfer reaction of the carbon centered radicals to thiol and subsequent addition of the thiyl radicals to vinyl double bonds during copolymerization strongly affect the copolymerization kinetics of this system. The effect of thiol on vinyl acrylate polymerization in the presence of oxygen is particularly significant due to the role of thiol in reducing oxygen inhibition. Two free-radical chain processes occur in both the presence and absence of oxygen.
ACS Symposium Series
Lee, T. Y.,
Hoyle, C. E.
(2006). Copolymerization Mechanism of Photoinitiator Free Thiol-Vinyl Acrylate Systems. ACS Symposium Series, 941, 17-28.
Available at: https://aquila.usm.edu/fac_pubs/16148