|Friday, February 8, 4th Floor RIVERTOWER 11:00 am - 11:30 am|
|Partha Sengupta||Study of Physical States of Free Films of Pigmented and Non Pigmented Epoxy-Amine Coatings Annealed at High Temperature|
Co-Authors: Matthew Gillis, Michael D. Blanton, James W. Rawlins
Most commercial epoxy-amine coatings cured at room temperature have high residual solvent and unreacted monomers. These residuals have a direct effect on the physical state of the coating’s glass transition temperature (Tg), free volume, permeability, and water absorption. Free films of a pigmented and clear epoxy-amine coating were cured at room temperature for seven days and annealed at 70 oC, 120 oC, and 150 oC for four hours. Annealing at increasingly higher temperatures resulted in lower residual content and a higher degree of cure. It was noted that the Tg increased by ~ 40% upon annealing the coating at 150 oC for four hours. Crosslink density, molar density, thermal expansion coefficient, and oxygen permeability were also measured for all the coatings. Molecular free volume was determined by measuring the fluorescence emission response of molecular rotor probes incorporated into polymer films. The results also demonstrated the effect of pigmentation on the physical states of the coating at higher annealing temperatures.