Glass transition temperature of epoxy amine coatings
Glass transition temperature (Tg) of commercial epoxy–amine marine coatings is among the most important thermo-mechanical properties which determine the performance of the individual coat and the whole coating system. Ingress of (sea) water and temperature are known to have an influence on the Tg of model epoxy–amine coatings. A new work shows the use of thermal analysis techniques like temperature-modulated differential scanning calorimetry (MDSC) and dynamic mechanical analysis (DMA) to study the effect of water immersion and immersion temperature on the Tg of four different commercial epoxy–amine coatings. In addition, Fourier transform infrared (FTIR) spectroscopy was used to study the chemical changes that occurred in the epoxy–amine network upon immersion in water at 40 and 60°C.
Tg is significantly influenced
The results obtained clearly show that the Tg is significantly influenced by water and water immersion temperature if the Tg (or the Tg region) of the epoxy–amine coating is lower than the immersion temperature. FTIR results showed that chemical changes can happen in the epoxy–amine network upon water immersion. Practical example of the effect of Tg of coatings on their protective performance has been demonstrated by using the NACE TM-0174 standard’s equipment which showed that the low Tg epoxy–amine coatings will lose their protective properties earlier than the high Tg coatings when exposed to similar test conditions
The study has been published in Journal of Coatings Technology and Research, Volume 20, Issue 3, May 2023.