Wood consolidation through an epoxy‐acrylic gamma‐crosslinked three‐dimensional system

Abstract

Emerging technologies based on polymeric materials are progressively developed in order to preserve and consolidate cultural heritage artifacts. In this study, we aimed to obtain a hybrid polymer reliant on two types of thermosets that undergo irreversible crosslinking via ionizing radiation‐induced polymerization, the polymer's structure and characteristics being tailored using specific dose rates, doses, linear energy transfer and monomers ratio, in order to achieve the established performance requirements. Here, we demonstrate a covalently bonded 3D hybrid diepoxy‐triacrylic polymer that is chemically and dimensionally stable, intending to use it as a consolidant of highly degraded wooden artifacts in order to mitigate oxygen inhibition from radical chain reactions, to increase chemical and thermal stability, as well as to obtain a stiffer consolidated artifact, therefore more resistant to deformation. Various types of analytical techniques such as Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy, Mass Spectrometry or Thermal analysis were performed in order to support our strategy and predictions regarding the synergistic effect given by gamma irradiation‐driven crosslinking through simultaneous cationic and radical chain growth polymerization reaction mechanisms. We achieved a homogenous polymeric formulation and wood‐polymer composite materials with high modulus of elasticity, therefore providing up to a twofold increase in Young's modulus in the consolidated wood, a good chemical resistance to various solvents and outstanding thermal resistance up to 381°C. Consequently, the consolidation methodology, as well as mechanical testing, analytical and morphological characterization of the resulted composite will be discussed. Apart from consolidating cultural heritage wooden artifacts, this synthetic route and impregnation methodology provide opportunities for wood‐polymer composites in a wealth of applications as reinforced wood‐based materials.