Polyvinyl alcohol and allyl α, α'‐trehalose copolymers for a sustainable strengthening of degraded paper

• Published in: Journal of applied polymer science 2022-05, Vol.139 (17), p.n/a
• Main Authors: Poggi, Giovanna, Papacchini, Alessandra, Baracani, Sara, Cappitti, Alice, Marini, Gioia, Marrini, Matteo, Giorgi, Rodorico, Salvini, Antonella
• Format: Article
• Language: English
• Subjects: applications; Biopolymers; Bonding strength; Carbohydrates; Cellulose; Copolymers; Degradation; Materials science; Mechanical properties; Mechanical tests; Monomers; other wood products; Polymers; Polyvinyl alcohol; renewable polymers; Strengthening; Trehalose; Vinyl acetate
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.52011

Acid‐catalyzed hydrolysis of glycosidic bonds is the most important degradation mechanism affecting cellulose‐based materials. It results in the decrease of DP and in the loss of the original mechanical properties. The neutralization of acidity is therefore one of the most efficient ways to hamper the degradation of cellulosic artworks. However, in the case of acidic and strongly degraded artifacts, in addition to deacidification, a consolidation treatment must be performed. To this aim, a new class of biopolymers, obtained by a synthetic procedure that considers the principles of Sustainable Chemistry, was investigated. Three allyl saccharide/vinyl acetate copolymers, having different molar ratios between starting monomers, were prepared using α,α'‐trehalose, and used to synthesize the corresponding allyl saccharide/vinyl alcohol copolymers. The use of saccharide derivatives as monomers improves the affinity and compatibility of the biopolymer with the artifacts to be treated. After characterization, the efficacy of the copolymers in the strengthening of degraded paper was evaluated with mechanical tests. The most effective system was thus selected for further testing. Its performance was compared to that of Klucel G®, a commercial product belonging to the class of cellulose derivatives, which are largely used in conservation practice. Degraded paper artworks usually require the application of strengthening agents. To this aim, a new class of biomaterials, obtained from renewable sources with a synthetic procedure that considers the principles of Sustainable Chemistry, is here reported. The use of saccharide derivatives enhances the affinity of strengthening agents with cellulosic artworks, resulting in an effective consolidation of fragile paper samples.