Branched Base-Amplifying Oligomers Enhancing UV-Curing of Epoxy Resins
✍ Scribed by Ken'ichi Aoki; Kunihiro Ichimura
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 269 KB
- Volume
- 210
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
This paper describes the preparation and the enhancing effect on anionic UV‐curing of epoxy resins of three and four‐armed oligomers bearing 9‐fluorenylmethyl carbamate residues, which displayed the autocatalytic formation of primary amino residues triggered by a photogenerated amine. The branched oligomers were readily synthesized by the Michael addition of the corresponding polythiol with 9‐fluorenylmethyl 2‐acryloyloxyethylcarbamate, which were obtained from 9‐fluorenylmethanol and commercially available 2‐isocyanatoethyl acrylate. Films of poly(glycidyl methacrylate) and a glycidylated novolac resin doped with a photobase generator exhibited boosted photosensitivity leading to photoinsolubilization in the presence of the base‐amplifying oligomers. The more marked effect of the branched oligomers on UV‐curing of epoxy resins was demonstrated by using films of a fluid epoxy, which were converted into hard films after UV exposure and post‐exposure baking, whereas no hardening occurred in the absence of the oligomers.
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