关键词: 纤维素, 辐照降解, 辐照交联聚合, 辐照接枝改性

Abstract: Cellulose irradiation technology uses high-energy ionizing rays as the energy source, such as α?rays, β?rays, γ?rays, X?rays, electron beams, etc., by which, cellulose is radiated so that it produces free radicals and further initiates a series of reactions such as polymerization, cleavage, crosslinking, grafting, and so on, followed by cellulose degradation or modification. The extent of cellulose polymerization, cleavage, grafting, crosslinking can be adjusted by changing the irradiation dose and reaction conditions. Unlike traditional chemical modification methods such as thermal cross?linking and polymerization, cellulose irradiation modification technology can accomplish the modification task that is difficult to achieve by traditional methods without the addition of other catalysts or chemical reagents. The modification of cellulose using irradiation technology has the advantages of easy pretreatment and post?treatment, energy?saving, and little waste. The application of irradiation technology in cellulose modification has become a hot spot in the field of nuclear technology in recent years. Irradiation technology utilizes physical or chemical reaction induced by ionizing radiation (such as crosslinking, polymerization, grafting, degradation, etc.) to produce or modify materials, and irradiation technology is different from traditional chemical methods, which utilize the radiation of high?energy electrons or rays into the interior of matter so that they generate free radicals and initiate a series of irreversible changes that alter material properties at the molecular level. By this physical means, reactions such as cellulose polymerization, cleavage, or graft crosslinking can be achieved without the use of catalysts. More critically, the series of chemical reactions evoked under an irradiation environment is expected to provide cellulose products that are difficult to synthesize by other methods, providing opportunities for the improvement of natural cellulose with the development of new products from downstream derivatives. In this work, an overview of current irradiation techniques for cellulose and their underlying reaction mechanisms is given, which includes cellulose film materials, cellulose hydrogels, cellulose crystallites/nanomaterials, and the irradiation environment for the irradiation modification process of cellulose, including solvents, sensitizers, temperature, irradiation dose, ambient atmosphere, crystallinity, etc., is summarized.

Key words: Cellulose, irradiation degradation, irradiation crosslinking, irradiation graft modification