Browsing by Subject "cultural heritage materials"

In this thesis the suitability of Nuclear Magnetic Resonance (NMR) spectroscopy in the identification of rubbers in museum collections is discussed through a literature review and experimental work where samples from the rubber collection of Tampere Museums were analysed with different NMR techniques. The literature part of this thesis focuses on recent (2011-2020) scientific publications on analytical instrumental techniques used in the identification of cultural heritage plastics. Vibrational spectroscopy methods utilizing hand-held or portable devices have been the most prominent methods used in characterization of historical plastics materials. Bench-top devices and analytical techniques requiring sampling were used to acquire more detailed analysis results. However, NMR spectroscopy was not used as the main analysis technique in the reviewed publications. In the experimental part altogether 21 rubber object samples and 8 reference samples were identified using 1D and 2D NMR techniques in solution state. Three samples were additionally analysed with solid-state High Resolution Magic Angle Spinning (HRMAS) NMR spectroscopy. The chemical structures of the samples were confirmed with these methods. To further explore fast and more automated identification of the rubber samples a statistical classification model utilizing acquired solution-state 1H NMR data was developed. Three rubber types were chosen for the analysis. The model was created using analysis data from the museum object samples and validated using the reference sample data. Identification rate of 100 % was achieved.