A comparative thermogravimetric study of waterlogged archaeological and sound woods

Abstract

Waterlogged archaeological woods Pinus pinaster and Fagus sylvatica L. were analyzed by using TG technique. Degradation processes ascribable to the holocellulose decay were evidenced at nearly the same temperature for sound and archaeological samples. The residual matters at 600 and 900°C of the sound woods are much lower than those of archaeological waterlogged woods in agreement with the presence of inorganic materials encapsulated during the burial into the marine environment. It was proposed a new protocol to rapidly calculate the maximum water content parameter, which is related to the wood degradation state. TG experiments at variable heating rates were performed to obtain kinetic parameters for the degradation process. The Flynn-WallOzawa and Friedman approaches allowed us to calculate the activation energy, which is significantly different for the sound and the archaeological woods.

Comparative study of historical woods from XIX century by thermogravimetry coupled with FTIR spectroscopy

“…Prior to their preservation, the wooden artworks should be properly characterized in order to determine the structural and compositional features of the woods. In this regards, an extensive investigation of the wooden materials can be achieved by using several diagnostics techniques, such as Nuclear Magnetic Resonance (NMR) spectroscopy (Bardet et al 2002;Žlahtič Zupanc et al 2019;Iwamoto et al 2019), X-ray diffraction analysis (XRD) (Carrillo-Varela et al 2018), Fourier Transform Infrared (FTIR) spectroscopy (Popescu et al 2007;Emmanuel et al 2015;Broda and Popescu 2019), Scanning Electron Microscopy (SEM) (Guo et al 2006;Borysiak 2013;Lin et al 2018), Atomic Force Microscopy (AFM,) (Notley and Wågberg 2005;Casdorff et al 2017) and thermal analyses (Cavallaro et al 2011a;Sebio-Puñal et al 2012;Blanco et al 2017;Girometta et al 2017).…”

Thermal degradation chemistry of archaeological pine pitch containing beeswax as an additive

“…Varying proportions of beeswax were added to the replicas and studied by a multi-analytical approach comprising the use of gas chromatography/mass spectrometry (GC/MS) and thermoanalytical techniques (DSC, TG and TG-FTIR). DSC and TG analysis have already been successfully used to investigate archaeological woods [18,19], and have been used to highlight interactions among pigments and fluid binders such as proteins, linseed oils and alkyd resins [20][21][22][23][24]. Consequently, we believe that they could also help us to understand the interaction between pine pitch and beeswax and to give an idea about the relative proportion of pine pitch and beeswax in unknown archaeological adhesives.…”

Measuring the chemical composition of waterlogged decayed wood by near infrared spectroscopy

“…These chemical changes cause micromorphological deterioration of cellular tissue of wood [6]. Various analytical techniques, like FT-IR spectroscopy, Py-GC/MS, TGA and NMR might be applied for estimating the degradation state of archaeological wood [7][8][9]. Among them, spectroscopic techniques are the most promising to be used as a routine methodology, because they are broadly diffused, easy to manage and not too difficult to interpret [10].…”