Fabrication of hydrophobicity and dimensional stability in Liriodendron tulipifera wood by combination of polyethylene glycol (PEG) impregnation and propyltrimethoxysilane (PTMS) surface coating

Dimensional stabilized treated wood can preserve its natural properties and be used in some humid environments. It is necessary to develop an effective treatment method. This study reported a technique that gets refined internally and externally for improving wood dimensional stability. Herein, polyethylene glycol (PEG) impregnation was the ‘internal’ factor and propyltrimethoxysilane (PTMS) vapor deposition was the ‘external’ factor. Both were jointly applied to treat Liriodendron tulipifera wood. FTIR, XPS and XRD were used to analyze the chemical changes and indicated new bonds formed among PEG, PTMS and wood. Micromorphology of modified wood was observed by SEM. Weight percent gain after PEG and PTMS coating was about 77%. The water contact angle of combined modified wood was greater than 135°. Reduction of pores in modified wood is another reason for hydrophobicity. The additive effect of PEG and PTMS significantly reduced the water absorption of modified Liriodendron tulipifera wood, with the PTMS coating potentially mitigating the leaching of PEG, markedly reducing the dimensional changes of the wood. This demonstrates the wide applicability, durability, and dimensional stability of PEG/PTMS-modified wood.