FTIR studies of the curing reactions of palm oil alkyd–melamine enamels
✍ Scribed by Seng-Neon Gan; Boon-Yeow Tan
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 136 KB
- Volume
- 80
- Category
- Article
- ISSN
- 0021-8995
- DOI
- 10.1002/app.1336
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Three alkyds of high hydroxyl numbers with oil lengths of 21, 30, and 41 were prepared from crude palm oil. The excess hydroxyl groups provided good compatibility with melamine resins, and also served as sites for crosslinking reactions. They were made into baking enamels by blending with 20% of a commercial melamine resin. All of them could be cured at temperatures below 200°C although thermodecomposition might occur above 290°C. The dry‐hard time of these enamels cured at temperatures between 140–180°C ranged from 10 to 180 min. Fourier transform infrared spectroscopy could be used to follow the major curing reactions. The absorbance of OH and NCH~2~OCH~3~ groups showed significant reduction. The changes in the absorbance of these peaks with time and temperature were investigated. The predominant reaction was identified as the formation of methylene ether linkages. However, the self‐condensation reactions of the amino resin and ester linkages did not occur to any noticeable extent. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2309–2315, 2001