Journal article
Photopolymerization of pigmented thiol–ene systems
Polymer (Guilford), Vol.45(9), pp.2921-2929
2004
DOI: 10.1016/j.polymer.2004.02.038
Abstract
Photopolymerization kinetics and optical properties of pigmented thiol–ene coatings were investigated using photo-DSC, real-time FTIR, colorimetry, and AFM. Pigment has no deleterious effect on the unique ability of thiol–ene systems to photopolymerize in air. When trimethylolpropane tris-(3-mercaptopropionate) is incrementally added to tripropylene glycol diacrylate with and without calcium lithol rubine, a red organic pigment, the photopolymerization rate in nitrogen steadily decreases due to a shift in the polymerization mechanism from an acrylate homopolymerization to a thiol–ene copolymerization. However, the photopolymerization rate of pigmented and non-pigmented systems in air significantly increases with increasing thiol concentration, ultimately reaching a maximum at approximately 35 mole percent trifunctional thiol. The increase in rate is due to chain transfer from the non-reactive peroxy radical to the thiol. Thiol groups reduce oxygen inhibition to a greater degree than standard additives such as
N-methyldiethanolamine,
N-vinyl pyrrolidinone, and thioether containing trifunctional vinyl esters. For a typical acrylate based pigmented photocurable system, greater than 10
wt% photoinitiator is required to achieve a photopolymerization rate equivalent to a comparable thiol–ene system with 1
wt% photoinitiator in air. AFM and colorimetric data indicate that addition of trifunctional thiol has no deleterious effect on pigment dispersion and may in fact increase dispersion quality.
Details
- Title: Subtitle
- Photopolymerization of pigmented thiol–ene systems
- Creators
- T.M Roper - Department of Polymer Science, University of Southern Mississippi, Box 10076, Hattiesburg, MS 39406-0076, USAT Kwee - Department of Polymer Science, University of Southern Mississippi, Box 10076, Hattiesburg, MS 39406-0076, USAT.Y Lee - Department of Polymer Science, University of Southern Mississippi, Box 10076, Hattiesburg, MS 39406-0076, USAC.A Guymon - Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA 52242, USAC.E Hoyle - Department of Polymer Science, University of Southern Mississippi, Box 10076, Hattiesburg, MS 39406-0076, USA
- Resource Type
- Journal article
- Publication Details
- Polymer (Guilford), Vol.45(9), pp.2921-2929
- Publisher
- Elsevier Ltd
- DOI
- 10.1016/j.polymer.2004.02.038
- ISSN
- 0032-3861
- eISSN
- 1873-2291
- Language
- English
- Date published
- 2004
- Academic Unit
- Chemical and Biochemical Engineering
- Record Identifier
- 9984004086002771
Metrics
16 Record Views