Impregnation of Wood Derived Scaffolds with Cellulose Acetate

The investigation of engineered wood products seems to be an essential column to reach sustainable development goals. For this reason, shortcomings of natural wood need to be exceeded by the means of chemical and physical modification. The presented approach contains the preparation and characterization of cellulose acetate composites with high cellulose content and hierarchical structure. In order to get mesoporous scaffolds, a delignification process of native beech wood veneers is realized with acetic acid and hydrogen peroxide. Thereby porosity is increased from 54 to 72%. It was found, that the intensity of the delignification is responsible for increasing porosity and shifting average pore diameter. Subsequent vacuum impregnation of the scaffolds with cellulose acetate (CA) is performed resulting in maximal WPG of 52.7%. In this way, the delignified wood structure, can be reinforced by polymer impregnation. Not only tensile strength is increased from 47 to 85 MPa but the water contact angle also increases from 30 to 51° indicating that the polymer contributes to enhanced hydrophobicity. Nevertheless, the anisotropic structure of wood is an obstacle for homogeneous impregnation. Wood is a lightweight sustainable material, such as the polymer cellulose acetate, which can be derived from wood as well. The combination of both yields in appealing properties but also challenging processing.