Characterising plasticised cellulose acetate-based historic artefacts by NMR spectroscopy: A new approach for quantifying the degree of substitution and diethyl phthalate contents

As one of the first semi-synthetic plastics produced industrially, cellulose acetate (CA)-based artefacts represent valued items in museum collections and archives which, however, present stability issues. High temperature relative humidity conditions have long been known to promote changes CA properties, for instance, due deacetylation polymer chains loss plasticiser from matrix. However, there is a need improved methods quantification deacetylation. In this context, contribution presents new approach enabling investigation degradation processes historic plasticised CA-based which based on high-resolution proton nuclear magnetic resonance spectroscopy (1H NMR). The proposed allow simple fast diethyl phthalate contents average degree substitution (DS), while requiring no extractive separation between matrix prior analysis. Both are demonstrated by their application towards series reference samples, artificially aged materials. Our analysis indicates that content DS can be accurately quantified using 1H NMR both compared analyses performed infrared spectroscopy.