The application of FTIR spectroscopy on characterization of paper samples, modified by Bookkeeper process

Paper and other lignocellulosic materials undergo the destruction as a result of ageing, influenced by various factors and accelerated by the formation of acids from components, used during its production [S. Katuščák, Wood Res. 45 (2000) 1; S. Katuščák, L. Ďurišová, Wood Res. 118 (1988) 75]. Various deacidification processes were developed in an order to prevent or eliminate acidic destruction. Bookkeeper, based on MgO dispersion in perfluoroheptane, is the widely used one [J. Hanus, J. Rychlý, J. Mináriková, L. Matisová-Rychlá, S. Katuščák, M. Vrška, V. Bukovský, in: J. Kollar, M. Strlic, J.B.G.A. Havermans (Eds.), Proceedings of the International Conference on Durability of Paper and Writing, Ljubljana (Slovenia), November 16–19, 2004, p. 22].In present work, the effect of its application is studied by means of FTIR DRIFT technique in an order to fill up the lack and the certain contradiction of information about its action on real paper samples. The spectral changes in Bookkeeper modified samples comparing to reference (unmodified sample), along with the influence of various ageing conditions (temperature 23.3, 35 and 80 °C at relative humidity 81 and 98%) were investigated.The application of Bookkeeper reagent causes significant changes mostly in the region of 3700 cm−1, assigned to the coordination of stretching vibrations of OH groups coordinated with Mg2+ ions; 3000/1600 cm−1—valence vibrations of OH groups of water and hydrogen bond structures; in the region 1740–1720 and 1630–1650 cm−1 indicating the changes in carbonyl/carboxylate content, which also influences the relative humidity and the rise of temperature, accelerating the transformation of carbonyls to carboxylates.