Hygrothermal ageing of dry gelatine adhesive films

Hygrothermal ageing of dry gelatine adhesive films: Microstructure-property relationships

Mosleh, Yasmine (TU Delft Bio-based Structures & Materials)
van Die, M. (TU Delft Structural Integrity & Composites)
Gard, W.F. (TU Delft Bio-based Structures & Materials)
Breebaart, Iskander (Rijksmuseum)
van de Kuilen, J.W.G. (TU Delft Bio-based Structures & Materials; Technische Universität München)
Van Duin, Paul (Rijksmuseum)
Poulis, J.A. (TU Delft Adhesion Institute)

2024

Gelatine adhesives, also known as animal glues, are collagen-based water-soluble biopolymers derived from vertebrate connective tissues. One of the various fields in which gelatine adhesives are widely used is the conservation of cultural heritage such as decorated furniture and panel paintings. It is observed that, with time, the failure in these objects often occurs along the adhesive bondlines. Given the moisture and temperature sensitivity of these adhesives, obtaining knowledge of their long-term behaviour, when exposed to climate variations, is pivotal. Here, the influence of hygrothermal ageing (exposure to a combination of elevated temperature and relative humidity (RH) cycling) on the microstructure and macroscopic properties of four different types of gelatine adhesives is investigated. These adhesives were selected from different animal origins namely bovine, rabbit, and fish with different Bloom strengths. It was observed that ageing cycles interfere with the most critical structural feature of protein chains namely triple helices. A clear decay in triple helix content at the micro-scale, determined by Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD) techniques, was observed which had implications on the macroscopic properties of these adhesives such as reduction of strain to failure and toughness (strain energy density to failure). The rate of decay in properties was revealed to be the highest in the adhesives with the lowest triple helix content. This study provides a scientific view of microstructure-property relationships in gelatinous adhesives as a function of environmental ageing, and stipulates the underlying mechanism of the degradation of mechanical properties as the loss of structural triple helices, regardless of the animal origin.

Hygrothermal ageing
Gelatine
Adhesive
Cultural heritage
Triple helix

http://resolver.tudelft.nl/uuid:1475d5d6-0e4c-4354-a05e-552cb44ffa6d

https://doi.org/10.1016/j.ijadhadh.2024.103654

0143-7496

International Journal of Adhesion and Adhesives, 131

Institutional Repository

journal article

© 2024 Yasmine Mosleh, M. van Die, W.F. Gard, Iskander Breebaart, J.W.G. van de Kuilen, Paul Van Duin, J.A. Poulis