The Cross‐Infectious Degradation of Plasticized Poly (Vinyl Chloride) and Cellulosic Materials

This study investigates how plasticized poly (vinyl chloride) (PVC-P) interacts with cellulosic materials during thermal aging in direct contact. The presence of cellulosic material triggers the migration of both the dioctyl phthalate (DOP) plasticizer and the calcium zinc stearate (CaSt₂/ZnSt₂) thermal stabilizer, while PVC-P dehydrochlorination under these conditions generates enough hydrogen chloride (HCl) to accelerate cellulose depolymerization.

Plasticized poly (vinyl chloride) (PVC-P), widely used in the 20th century, poses significant risks to numerous artifacts preserved in cultural heritage institutions due to the release of hydrochloric acid (HCl) and plasticizers. While previous studies have examined the impact of PVC-P emissions on cellulose, this study is the first to investigate cross-infectious degradation in systems where PVC-P is in direct contact with cellulosic materials. The interaction between PVC-P and two types of cellulosic materials—pure cellulose paper (Whatman paper) and lignin-containing acidic paper (NOVO paper)—under accelerated aging at 90 °C is examined. In PVC-P, direct contact with the cellulosic material lead to the migration of both the plasticizer and the thermal stabilizer. Dehydrochlorination of PVC-P under these conditions generates enough hydrogen chloride (HCl) to accelerate cellulose depolymerization, followed by a faster decline in surface pH. This study shows that cellulosic materials can destabilize PVC-P while also undergoing degradation as a result of this interaction. In the case of more heterogeneous cellulosic materials, this interaction can lead to uneven degradation of the PVC-P.

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