Chemical incorporation of thioxanthone into beta-cyclodextrin and its use in aqueous photopolymerization of methyl methacrylate
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, vol.196, no.1, pp.33-37, 2008 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 196 Issue: 1
- Publication Date: 2008
- Doi Number: 10.1016/j.jphotochem.2007.11.009
- Journal Name: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.33-37
- Keywords: photopolymerization, thioxanthone, cyclodextrin, host guest complexes, aqueous polymerization, FREE-RADICAL POLYMERIZATION, HOST/GUEST COMPLEX, INITIATION, SYSTEMS
- Yıldız Technical University Affiliated: Yes
Abstract
Photoinitiated free radical polymerization of methyl methacrylate(MMA) inaqueous solution via hydrogen abstraction mechanism was described. For this purpose, thioxanthone (TX) chromophoric group was chemically incorporated into beta-cyclodextrin (beta-CD) by a simple esterification process. The resulting thioxanthone photoinitiator (TX-beta-CD) exhibited similar spectral characteristics and photoactivity to that of the parent TX molecule. Host guest complexes of MMA with TX-beta-CD in water, in the presence of N-methyldiethanol amine (NMDEA) as a hydrogen donor, facilitated photoinitiated free radical polymerization in aqueous medium. The postulated mechanism is based on the intermolecular reaction of photoexcited triplet TX moiety of TX-beta-CD with NMDEA. The resulting amino alkyl radicals initiate the polymerization. (c) 2007 Elsevier B.V. All rights reserved.