Wood composites modified with waterborne hyperbranched polyacrylate dispersed organo‐montmorillonite emulsion and the permeability investigations by surface characterizations

Abstract A novel waterborne hyperbranched polyacrylate (HBPA) dispersed organo‐montmorillonite (OMMT) emulsion was synthesized in laboratory. The sapwood of Cathay poplar (Populus cathayana Rehd.) was modified with the emulsion via vacuum treatment for polymer impregnated wood composite with cross section sealing off. Some surface characterization was carried out to analyze the impregnation depth. The results showed that OMMT and HBPA successfully penetrated into the wood cell wall with completely exfoliated OMMT and formed a hydrophobic film covering on the inner surface of cell wall lumen, which improved the surface hydrophobicity and mechanical properties of wood cell wall. With increasing impregnation depth, the improvements decreased, which was associated with the limited impregnation ability of the modifiers only with the pathway of radial and tangential sections. Thus, for better modification, the cross section of the wood must be unobstructed.