Curing behavior of acrylate–urethane system

✍ Scribed by Deben Chen; Xu Qi; Zonghua Zhou; Anyong Zhong; Zougying Du

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 376 KB
• Volume: 62
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19961205)62:10<1715::aid-app23>3.0.co;2-z

✦ Synopsis

The curing behavior of a two-component system-acrylate copolymer I (the main resin) and monobutyl glycol ether and diethanolamine blocked 2,4-toluene diisocyanate I1 (the crosslinker)-was studied by torsional braid analysis (TBA), Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC). The results show that the curing process consists of two steps: First, the hydroxyl-blocked isocyanate group (NCO) thermally dissociates to produce a free isocyanate group, which can react with the hydroxyl of the acrylate copolymer. Second, the amino-blocked isocyanate thermally dissociates and regenerates a free isocyanate group which can react with the hydroxyl group of the acrylate copolymer. Thus, the crosslinked network is obtained. When the organotin catalyst was added into the system, the curing temperature and the curing time was shortened efficiently. The Arrhenius apparent activation energy for curing was calculated in this study. 0 1996 John Wiley & Sons, Inc.