The core issue of the protection and preservation of paper documents and cultural relics is to prolong their lifetime as much as possible, and regular deacidification of paper documents and cultural relics is a widely used method for extend the lifetime. In recent years, there has been increasing attention on how to evaluate the effectiveness of deacidification. Chinese traditional handmade paper serves as an important medium for the printing of ancient books and the creation of calligraphy and painting, but there is a lack of research on the evaluation of its deacidification effect. This study selected handmade mulberry paper as the research object, and comprehensively evaluated the effectiveness of paper deacidification based on life expectancy. The kinetic analysis of dry-heat aging process of mulberry paper showed that the degradation of mulberry paper follows the classical first-order degradation kinetics. Then, the life expectancy of mulberry paper before and after deacidification was predicted using first-order kinetics and Arrhenius equation. The results showed that the life expectancy of mulberry paper increased by approximately 5 times after deacidification. Therefore, we can conclude that even for traditional Chinese handmade paper, which already has a long lifetime, regular deacidification still can significantly extend its lifetime. In addition, several parameters, including pH, tensile index, color difference and oxidation degree, were measured and analyzed before and after deacidification. The pH value and tensile index testing showed that the deacidification process increased the surface pH value of paper, which effectively inhibited the acidification rate of the paper and slowed down the decline of the tensile index. The results of chromaticity and Fourier transform infrared spectroscopy measurement showed that color difference and oxidation degree of paper after deacidification were slightly increased. The microscopic and optical images showed that the morphology of the fibers was basically the same before and after deacidification. The results of the study can be extended to the evaluation of deacidification effectiveness and life expectancy of other types of paper, and providing a multi-faceted and more practical methods and experimental basis for evaluation of paper deacidification effectiveness.

Key words: paper deacidification, effectiveness of deacidification, life expectancy of paper, degradation kinetics