Spectroscopic Characterization of Sensitive Museum Plastic-Based Objects

Museum collections are constantly expanded to include plastic-based materials. Taking into account the dynamic development of polymer chemistry, presumably in the nearest years, the number of museum objects made of plastic continues to grow. Contrary to popular opinions, items made of plastic are not very durable, and they are easily susceptible to environmental conditions. The degradation process already starts when the object is created, but its speed and paths can be diverse. In the worst case, the degradation products of certain materials are harmful not only to them, but also to other objects stored in their surroundings. The presented work aims to improve a non-destructive method that allows for easy recognition of materials used in objects created from polymers in the collection of the National Museum in Krakow. Hyperspectral imaging (HSI) with SWIR spectral range of 1000–2500 nm and portable Raman spectroscopy were used to identify and characterize the polymers and additives composing the objects. Additionally, microfading testing (MFT) was carried out to investigate the reaction of plastic museum items to exposure to high intensity light in the visible range. Understanding the materials used to create the objects and new materials introduced as part of conservation treatments will allow to develop methods to minimize their physicochemical degradation. This will permit to make informed decisions regarding the care and display of these objects to ensure a safe exhibition and storage.