Hj. Flammersheim et W. Kunze, DSC INVESTIGATIONS ON A COMMERCIAL PHOTOCURING SHEET MATERIAL, JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, 52(1), 1998, pp. 125-130
The photopolymerization of a commercial sheet material as used in the
dental laboratory was investigated by using the photocalorimeter DSC7/
DPA7 (Perkin-Elmer). Using normal reaction conditions (light wavelengt
h less than or equal to 400 nm, light intensity greater than or equal
to 1 mW cm(-2) and sample thickness less than or equal to 2.5 mm), the
curing was completed within few min. The reaction rate was nearly ind
ependent on the light wavelength in the range between lambda=300 and 3
80 nm, but decreased distinctively at longer wavelenghts. After desmea
ring the DSC curves, the dependence of the reaction rate on light inte
nsity and sample thickness could be described in very good approximati
on by an equation derived by Tryson [1]. Comparable with pure acrylate
s or methacrylates, a pronounced dark reaction was found after interru
ption of the illumination.