New insights in the durability of flax fibres through the study of ancient Egyptian yarns – ANUBIS

Man has always had a close relationship with flax, one of the first domesticated plants, particularly in the Fertile Crescent and ancient Egypt. From the earliest times, its fibres, with their exceptional properties and fineness, have been used for clothing, household linen or even for making sails and ropes. Today, new industrial markets are opening up for this plant; the remarkable mechanical performance of its fibres makes it a choice reinforcement for developing innovative, environmentally friendly and recyclable biobased materials. Through an original and transdisciplinary archaeometric approach, the ANUBIS project aims to build a bridge between archaeology and materials science. Its main scientific objectives are i. to understand how the structure of the fibres has evolved over time and through ageing, ii. to understand the evolution of the structure of defects and their role on the mechanical performance of the fibres, iii. to evaluate the impact of time on the composition and biochemical architecture of the walls and, as an ultimate objective, iv. to understand how the brittle areas of the fibres can be reduced in order to preserve them as well as possible and to optimally configure future biobased composites. After a selection phase of ancient flax yarns in different renowned museums, using an approach both related to their historical and architectural characteristics (IFAO), we will study in depth their structural, biochemical and mechanical characteristics. Defect areas, sensitive to ageing, will be particularly targeted, whether through biochemical (deep UV, NMR or X-ray diffraction - INRAE), mechanical (traction or mechanical mode atomic force microscopy - UBS) or structural (two-photon microscopy or X-ray nano-tomography - Synchrotron SOLEIL) analyses; innovative couplings (AFM-Raman or Traction-Tomography) between technologies will also be implemented. All of this data will then be used to develop numerical behaviour models, at the scale of yarns and fibres, but also to develop a predictive model of fibre and cell wall ageing. To this end, ANUBIS brings together a highly complementary and multidisciplinary consortium of recognized experts; its ambition is to contribute to the advancement of knowledge on flax fibres and, in particular, to acquire new knowledge on the ageing and durability of these fibres, in order to be able to develop, in the future, the biobased composites of tomorrow, which will be more durable and efficient.