The Effect of Alkali Treatment on Wood Crystalline Structure and Micro-Structural Model

Abstract

The penetrability of wood can be improved by alkali treatment. In this study, Chinese fir (Cunninghamia lanceolata(Lamb.)Hook) was treated by sodium hydroxide (NaOH) and sodium hydroxide-ultrasonic (NaOH/US). The NaOH solution was 3%, the impregnation time was 48h and the ultrasonic treatment time was 30min. The crystalline region of the pretreated samples was analyzed using X-ray diffraction (XRD), and the results showed that the diffractive peak of 002 crystal faces was lower and crystallinity decreased after the alkali treatment. It proved that some boding of crystalline region was cut off and area of amorphous increased. In this paper, molecular model was constructed to explain the effect of alkali treatment on wood crystalline structure.