Experimental research on the molecular-topological structure of oak (Quercus robur L.) and birch wood (Betula pendula Roth) and its shape-memory effect

Features and characteristics of wood as a natural smart material allow us to use it to create new smart biocomposite materials, intelligent systems and environments. The shape-memory effect of oak (Quercus robur L.) and birch (Betula pendula Roth) veneers was investigated. Thermomechanical spectrometry was used to study these two species, which makes it possible to establish the relationship between the deformation transformations and the nature of intermolecular interactions and the interchain organization of wood polymers. The quantitative and molecular relaxation characteristics of the topological structure were obtained for the characterization of the shape-memory effect for the permanent, temporary and after recovery shapes of birch and oak wood samples. The results showed a relationship between the quantities of shape-memory effect and changes in the molecular-topological structure. A reversible transformation of a topological structure was experimentally confirmed for birch and oak woods, with the formation of a temporary deformation and the recovery of the original permanent shapes.