Synthesis, cationic polymerization and curing reaction with epoxy resin of 3,9-di(p-methoxybenzyl)-1,5,7,11-tetra-oxaspiro(5,5)undecane
✍ Scribed by Pan, Caiyuan; Yuan, Jinying; Bai, Ruke
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 122 KB
- Volume
- 49
- Category
- Article
- ISSN
- 0959-8103
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✦ Synopsis
A new spiro ortho carbonate, 3,9-di(p-methoxybenzyl)-1,5,7,11-tetra-oxaspiro(5,5)undecane was prepared by the reaction of 2-methoxybenzyl-1,3-propanediol with di(n-butyl)tin oxide, following with carbon disul®de. Its cationic polymerization was carried out in dichloromethane using BF 3 -OEt 2 as catalyst. The [ 1 H], [ 13 C]NMR and IR data as well as elementary analysis of the polymers obtained indicated that it underwent double ring-opening polymerization. The polymerization mechanism is discussed. The curing reaction of bisphenol A type epoxy resin in the presence of the monomer and a curing agent was investigated. DSC measurements were used to follow the curing process. In the case of boron tri¯uoride-o-phenylenediamine (BF 3 -OPDA) as curing agent, two peaks were found on the DSC curves, one of which was attributed to the polymerization of the epoxy group, and the other to the copolymerization of the monomer with the isolated epoxy groups or homopolymerization. However, when BF 3 -H 2 NEt was used as curing agent, only one peak was present. IR measurement of the modi®ed epoxy resin with various weight ratios of epoxy resin/monomer was performed in the presence of BF 3 -H 2 NEt as curing agent. The results demonstrate that the conversion of epoxy group increases as the content of monomer increases. The curing process and the structure of the epoxy resin network are discussed.