Redefining Stability in Cultural Heritage Through Polymer Design: From Conservation Strategies to Plastic Degradation

Polymers play a central and multifaceted role in cultural heritage science, serving both as functional materials in conservation treatments, such as cleaning, consolidation, adhesion and protection, and as constituents of a wide range of historical artefacts, including paper and canvas, waterlogged wooden wrecks, musical instruments, and modern plastics used in art. Although numerous studies have examined the use of polymers in archaeology and cultural heritage conservation, most have focused on specific polymers, individual conservation treatments, or categories of artefacts. A comprehensive and integrated assessment of the multifunctional role of polymers, both as conservation materials and as constituents of heritage objects, remains lacking. The aim of this review is to provide a critical and comprehensive overview of natural and synthetic polymers in cultural heritage science, examining their applications in conservation treatments, their long-term stability and aging, and the challenges and opportunities associated with their preservation and sustainable use. This review examines the main classes of natural and synthetic polymers used in conservation, evaluating their mechanisms of action, performance, limitations, and long-term behavior across different applications. It also examines the chemical decomposition pathways and the resulting degradation phenomena occurring in polymeric materials, both as conservation products and as constituents of cultural artefacts, together with current stabilization strategies aimed at mitigating aging and deterioration. This review provides a critical appraisal of current challenges and future perspectives in cultural heritage conservation, highlighting emerging trends and research directions for the development of more effective, sustainable, and compatible polymer-based solutions for cultural heritage conservation.