Microstructural and Chemical Characteristics of Archaeological White Elm (Ulmus laevis P.) and Poplar (Populus spp.)

Abstract

The degradation states of archaeological white elm, with an age estimation of ~350 years, and poplar, with an age approximation of ~1000–1200 years, were studied by means of different chemical and microscopy analyses. Recently cut samples from the respective species were used for comparison reasons. The chemical composition analysis of the archaeological samples showed significantly low holocellulose values, while the lignin, extractive, and ash contents were considerably high, as compared with the recently cut samples. The Fourier-transform infrared (FTIR) spectroscopy also confirmed the changes in the chemical structure of the archaeological elm and poplar samples. The light and scanning electron microscopies illustrated that the erosion bacteria were the main degrading agent in both archaeological elm and poplar, although the hyphae of rot fungi were detected inside the vessel elements of the archaeological poplar sample.

Insights into cork weathering regarding colour, chemical and cellular changes in view of outdoor applications

“…The polysaccharide fraction was also affected with a small decrease of hemicelluloses by hydrolysis of xylose and arabinose units, although to a limited extent (the glucose-to-non-glucose ratio was 0.75). Studies on wood degradation induced by burial also refer that hemicelluloses are the most affected, while cellulose content remains almost stable over time [48][49][50]. Again the wet chemical results accord with the spectral observation (Fig 3), as discussed above, of a clear decrease of suberin-related bands as well as those of hemicelluloses, and show that surface ATR-FTIR spectroscopy is a very useful tool to evaluate chemical changes.…”

Functional Olive Pit Powders: The Role of the Bio-Based Filler in Reducing the Water Uptake Phenomena of the Waterborne Paint

“…Differently, the stretching region between 3000 to 2800 cm −1 corresponds the -CH group of cellulose, hemicellulose, and lignin [80]. The signal at around 1700 cm −1 can be assigned to the stretching vibrations of the unconjugated C=O group and specific moieties of the polymeric chains present in the lignocellulose, such as esters [81]. The band at 1460 and 1530 cm −1 represent the C-H deformation vibration and aromatic skeletal vibration of lignin, respectively [82].…”

Impact of High Concentrations of Cellulose Fibers on the Morphology, Durability and Protective Properties of Wood Paint

“…The band between 3400 and 3300 cm −1 , is representative to the stretching vibration of the -OH group [64], while the stretching region between 3000 to 2800 cm −1 can be associated with the -CH group of cellulose, hemicellulose, and lignin [65]. The peak at 1729 cm −1 corresponds to the stretching vibrations of the unconjugated C=O group and specific moieties of the polymeric chains present in the wood, such as esters [66]. The bands at 1592 cm −1 and 1460 cm −1 can be associated with the C=C benzene ring vibration of lignin and C-H deformation vibration, respectively [67].…”