Characterization of coil coatings by thermal analysis

The interrelationship between the network formation process and performance properties makes cure process studies critically important in the coil-coating industry. The objective of this work was to introduce thermal analysis into the evaluation of curing of uncured samples and in studies of the glass-transition temperatures of cured samples. Thermal analysis, dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC) were used to characterize gelation and curing of three types of samples: paints, coated sheets, and free films. In addition to the generally used three-point-bending and extension geometries, a cup-and-plate geometry also was used in analyzing gelation and curing of liquid samples. These thermal analyses are suited to the purpose of characterizing coil coatings. A correlation between PMT (peak metal temperature) and measured T<INF>g</INF> (glass-transition temperature) was found, as well as effectively distinguishing different curing conditions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2016–2022, 2003