“Material properties of historic parchment..." by Možir et al (2014)

Možir, A.; Cigić, I. K.; Marinšek, M.; Strlič, M.; “Material properties of historic parchment: a reference collection survey”, Studies in Conservation 59(3) (2014) 136–149.

Doi:10.1179/2047058413Y.0000000100 (restricted access)

Abstract:

Historic parchment is a complex biological material, and due to various methods of production or inks used, unknown environmental histories of objects and heterogeneous nature of animal skin, it represents a particular analytical challenge. Due to the number of variables it is likely that patterns in degradation of these historic objects can only be revealed by surveying the material properties of a significant number of real objects. In this work, a sacrificial collection of ca. 100 historic parchments (fifteenth to twentieth century) was characterized using a range of techniques available to conservation practitioners that can usefully be used to reliably and rapidly characterize parchment. We focused on micro-destructive methods, such as shrinkage temperature (Ts), as the most widely used indicator of parchment degradation. Lipid content, roughness, and ink pH were additionally measured, while a limited number of samples containing iron gall ink were also examined using scanning electron microscopy (SEM) and SEM-EDX, to explore the distribution of ink components. Even in the absence of detailed environmental histories, it is possible to acknowledge the significance of the effect of iron gall ink and its acidity, and of lipids on parchment degradation, as measured using Ts. This research reports valuable reference data, while the collection remains accessible for further research.

"Use of thermal analysis methods to asses the damage in the bookbindings of some religious books from XVIII century, stored in Romanian libraries" by Budrugeac et al (2014)

Budrugeac, P.; Cucos, A.; Miu, L.;"Use of thermal analysis methods to asses the damage in the bookbindings of some religious books from XVIII century, stored in Romanian libraries", Journal of Thermal Analysis and Calorimetry 116(1) (2014) 141–149
Doi:10.1007/s10973-013-3414-7 (restricted access)

Abstract: 

The scope of this work was the assessment of thermo-oxidative deterioration, hydrothermal stability, and crystalline zone deterioration of some bookbinding leathers from some religious books published in XVIII century stored in Romanian libraries. In this purpose, the following thermal analysis methods were employed: thermogravimetry/derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The thermo-oxidative damage of investigated leathers was characterized by the rate of the first thermo-oxidation process put in evidence in TG/DTG curves recorded in static air atmosphere. The hydrothermal stability was characterized by shrinkage temperature determined by DSC analysis of leathers in water excess. The damage of the crystalline zone of leathers was determined by DSC in nitrogen flow and DMA analyses. The qualitative damage for each leather and each kind of degradation was evaluated using the criteria resulted by thermal analysis of a large number of collagen-based materials (pure collagens, new and old parchments and leathers). The obtained results could be used for finding the best possible methods for preservation and/or restoration of the investigated bookbinding leathers.

"Assessing the microbiological risk to stored sixteenth century parchment manuscripts..." by Troiano et al (2014)

Troiano, F.; Polo, A.; Villa, F.; Cappitelli, F.; "Assessing the microbiological risk to stored sixteenth century parchment manuscripts: a holistic approach based on molecular and environmental studies", Biofouling 30(3) (2014) 299–311 

Doi:10.1080/08927014.2013.871539

Abstract:

The microbial risk for the conservation of seven sixteenth century parchment manuscripts, which showed brown discolouration putatively caused by microorganisms, was evaluated using non-invasive sampling techniques, microscopy, studies of surface-associated and airborne microflora with culture-independent molecular methods, and by measuring repository thermo-hygrometric values. Microscopic observations and ATP assays demonstrated a low level of contamination, indicating that the discolouration was not related to currently active microbial colonisation. Nevertheless, a culture-independent molecular approach was adopted to fully characterise surface-associated communities searching for biodeteriogens that could grow under appropriate thermo-hygrometric conditions. Indeed, potential biodeteriogens and microorganisms that are ecologically related to humans were found, suggesting the need to control the conservation environment and improve handling procedures. Microbial loads of air and thermo-hygrometric measurements showed that the repository was not suitable for preventing the microbial deterioration of parchment. A holistic approach to the assessment of risk of microbial deterioration of documents and heritage preservation is proposed for the first time.

"DMA and DSC studies of accelerated aged parchment and vegetable-tanned leather samples" by Cucos et al (2014)

Cucos, Andrei; Budrugeac, Petru; Miu, Lucreţia; "DMA and DSC studies of accelerated aged parchment and vegetable-tanned leather samples", Thermochimica Acta 583 (2014) 86–93.
DOI:10.1016/j.tca.2014.03.022 (restricted access)

Abstract:

The aim and the novelty of this work was the use of both dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC), in water and in dry state, for the investigation of the effects of temperature and relative humidity on degradation of recently manufactured parchments and vegetable-tanned leathers. The materials were subjected to accelerated ageing under action of heat and moisture for progressively increasing time lengths. The studies have proved that accelerated ageing causes a progressive decrease of the temperature of denaturation in water excess, but has no or minor effect on that in dry state. Also, under same ageing conditions parchments undergo a greater degree of deterioration than leathers, as evidenced by a more dramatic change in the DSC peaks (in water) and in the shrinkage curves (DMA). The results can be interpreted as a partial gelatinization occurring in the thermal conditions used for accelerated ageing. The paper presents the advantage of using both techniques, namely that DSC results can assist in interpretation of the DMA curves and that the good correlation of denaturation temperatures obtained by DSC and DMA ascertain these values. Such studies can be useful for understanding the processes that take place on natural ageing of historical parchments and leathers, as well as for establishing proper conditions of their storage.