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New insights into the degradation mechanism of cellulose nitrate in cinematographic films by Raman microscopy
Author(s) -
Neves Artur,
Angelin Eva Mariasole,
Roldão Élia,
Melo Maria João
Publication year - 2019
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5464
Subject(s) - raman spectroscopy , degradation (telecommunications) , nitric acid , nitrate , cellulose , microscopy , infrared spectroscopy , chemistry , materials science , spectroscopy , infrared microscopy , optical microscope , analytical chemistry (journal) , chemical engineering , inorganic chemistry , scanning electron microscope , environmental chemistry , organic chemistry , optics , composite material , telecommunications , physics , quantum mechanics , computer science , engineering
Abstract The degradation of cellulose nitrate cinematographic films stored inside an aluminum can was studied by infrared spectroscopy and Raman microscopy. Cellulose nitrate image heritage is strongly susceptible to degradation, being a major conservation challenge. Infrared spectroscopy has been the traditional technique in the assessment of the polymer degradation, but new in situ diagnostic tools to monitor the initial stages of degradation are needed. In this work, cellulose nitrate films were produced and irradiated as aging references to understand how chemical changes were observed in Raman spectroscopy. In comparison with infrared spectroscopy, this technique confirmed the mechanisms proposed in the literature and, at advanced stages of degradation, provided new relevant information detecting an intense peak at 1046 cm −1 associated to nitric acid. Comparing these results with the cinematographic films, it was observed that the plasticizers, which identification was more straightforward using Raman microscopy, have contributions in the regions were chemical changes occur, making it difficult to draw conclusions. Nevertheless, nitric acid and silver nitrate peaks were found in Raman spectra confirming the unstable and noxious environment inside de aluminum can and proving that Raman microscopy can be a valuable complementary in situ technique for cellulose nitrate degradation studies.