Pulsed Microwave-Induced Acoustics: An Indirect Method for Monitoring Depolymerization of Paper Via On-Line Measurements of Water Sorption/Desorption Kinetics

The application of the microwave-induced acoustic technique, developed in this laboratory, as an indirect sensor of depolymerization of paper via online measurements of water sorption and desorption kinetics in both lignin containing and lignin-free paper samples is described. Exposure of paper samples to gaseous NO 2 greatly accelerated the aging of paper and is shown by this technique to have significant effects on the water sorption characteristics. Implications of these observations, related to damages effected by exposure to free radical environments and the resulting embrittlement and depolymerization of paper samples, is discussed.