Study on anti-aging cultural paper using a combination of antioxidants and strengthening agents

• Using carboxymethyl cellulose (CMC) for paper reinforcement and exploring the optimal dosage. • CMC combined with antioxidant to improve the anti-aging property of paper. • Compare the free radical scavenging ability of multiple antioxidants and explore the optimal dosage. Paper, as an important carrier of information, is widely used in fields such as books, magazines, newspapers, etc. Paper that serves to transmit information and preserve culture is commonly termed "cultural paper". To ensure the long-term preservation of cultural heritage, anti-aging treatment for cultural paper is essential. Unlike the predominantly acidic papermaking processes of the 20th century, modern cultural paper typically employs a milder alkaline method. This weakly alkaline environment effectively inhibits acidification-induced aging; consequently, the primary aging mechanism in these papers is oxidative degradation. The widely accepted cellulose auto-oxidation mechanism involves free radical reactions, wherein hydroxyl and superoxide anion radicals play major roles. These radicals not only accelerate paper degradation but also compromise the effectiveness of strengthening agents. This study proposes a novel anti-aging strategy for cultural paper using a combination of antioxidants and strengthening agents. Results indicate that among four common cellulose derivative strengtheners, carboxymethyl cellulose (CMC) demonstrated the best reinforcing performance. When combined with antioxidants, a 0.08 % mass concentration mixture of tea polyphenol and sodium phytate (mass ratio 1:1) exhibited excellent free radical scavenging capability. Furthermore, this mixture effectively suppressed radical activity, significantly enhancing the durability of the CMC treatment without adversely affecting the paper's initial properties.