The resin extracted from the species of the Pinus genus (Pinaceae family) is a widely used material. Primarily, resins are made up of two types of diterpenoids: abietanes and pimaranes. Their composition changes with aging, affecting their chemical and physical properties; however, the chemical changes that occur during aging are not yet fully known.
View Article and Find Full Text PDFResins obtained from Pinus genus species have been widely used in very different fields throughout history. As soon as the resins are secreted, molecular changes start altering their chemical, mechanical and optical properties. The ageing processes are complex, and the chemical and structural changes associated with resin degradation are not yet fully known.
View Article and Find Full Text PDFPrecise microanalytical techniques are essential in many fields such as cultural heritage materials, showing complex layered microstructures containing a wide range of materials of diverse nature and hardness. Noninvasive sample manipulation and preparation is required to avoid, as much as possible, sample contamination, which may strongly limit the materials identification. The method proposed consists in the application of thin gold or carbon protecting layers before embedding the samples in synthetic resin for microtoming.
View Article and Find Full Text PDFAltarpieces and polychrome carved wood from the fifteenth century AD usually exhibit golden and silvery areas by the application of a very thin foil of metal. The metal foils were normally protected from the atmosphere by a varnish or resin which maybe either preserved or absent. Moreover, they were glued to the background surface by adhesive substances (egg yolk, drying oil or animal glue).
View Article and Find Full Text PDFSynchrotron radiation X-ray diffraction (micro-SR-XRD) and Fourier transform infrared spectroscopy (micro-SR-FTIR) are used in the non-destructive identification of reaction and aging compounds from micrometric ancient painting layers. The combination of the micrometer size and non-destructive nature of the techniques together with the high resolution and brilliance of the synchrotron radiation has proved to be a procedure most advantageous for the study of reaction, aging and degradation processes. Copper, lead and calcium carboxylates and oxalates are determined in the chromatic, preparation and alteration layers from 15th century egg tempera and oil paintings.
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