FT-IR ATR spectra and nanohardness measurements
as used to follow the progress in photocuring of polyester resins
Polimery 2001, No 7-8, 494
SummaryPhotocuring of a polyester resin layer 1.0-3.5 µm thick was followed in terms of FT-IR ATR spectroscopy and nanoindentation measurements. The hardness of the coating was reaffirmed to be related to exposure time (Fig. 3). FT-IR spectra showed the photocuring of the resin to follow the mechanism involving copołymerization of an oligoester with styrene (Fig. 4). FT-IR data were found to be well correlated (Re2 > 0.95) with nanoindentation data (Fig. 5). The curing degree disclosed a surface gradient (Fig. 3a), impossible to detect by conventional hardness measurements. This gradient continued to be maintained in the course of the curing reaction, a fact of possible consequence for polymer coating durability. By being focused on surface layer features, the nanoindentation technique provides valuable data that so far were underestimated by polymer technology.