CURING BEHAVIOR OF SELF-CROSS-LINKABLE POLYACRYLATE COATING - TBA ANDIN-SITU FTIR STUDIES

The curing behavior of a self-crosslinkable polyacrylate coating syste m was studied by torsion braid analysis (TBA), thermogravimetric analy sis (TGA), and in situ Fourier transform infrared (FTIR). The results of heating TEA showed that the curing process consisted of two stages: The first stage was the deblocking and crosslinking period-the major period of the curing process. The second stage was the deep-curing per iod. At the end of this stage, a tighter crosslinking network was obta ined. In addition, the detecting results of heating in situ FTIR prove d that the reaction occurring in the second stage concerned the reacti on of the deblocked isocyanate group and the NH group which came from urethane. In the end, the results of isothermal in situ FTIR showed th at the curing temperature affected the extent of crosslinking. The hig her the curing temperature, the deeper the curing extent. From the syn thetical consideration of the curing temperature and curing time, the optimum curing condition was 170 degrees C/10 min. (C) 1998 John Wiley & Sans, Inc. J Appl Polym Sci 69: 1599-1606, 1998.