WOOD RESEARCH Volume 61, Number 2, 2016
Hong Yun, Kaifu Li, Dengyun Tu, and Chuanshuang Hu

Effect of heat treatment on bamboo fiber morphology crystallinity and mechanical properties

This study aimed to investigate the fiber morphology, crystalline structure and mechanical properties of heat-treated bamboo. Moso bamboo was treated by superheated steam at 120, 140, 160, and 180ºC. Fiber morphology and crystalline structure of heat-treated Moso bamboo were researched by transmission electron microscope and X-ray diffraction. The mechanical properties of heat-treated bamboo were tested in the paper. The result showed that the relative crystallinity and length-width ratio of heat-treated bamboo were increased with increased temperature. The elastic modulus of bamboo was increased as the temperature rose from 120 to 140ºC. and then decreased with higher temperature, which was associated with the increase of the crystallinity.

WOOD RESEARCH Volume 62, Number 2, 2017
Hong Yun, Kaifu Li, Chuangshuang Hu, and Dengyun Tu

Adsorption and fixation of soluble fire retardancy in Populus russkii and Cunninghamia lanceolata

Flame retardant treatment is a common method of wood preservation. However, the factory usually uses the same approach to all the wood, but lack of targeted so as to cause waste. This study used poplar and Chinese fir as the species investigated. These species were dipped with boron-nitrogen-phosphorus (B-P) fire retardant. The influences on material loading of processing method, concentration of fire retardant, and drying method were investigated. The contents of B and P were tested by inductively coupled plasma optical emission spectrometry (ICP-OES), after distilled water washing and ultrasonic washing. The results showed that the volume loading increased with the concentration of fire retardant. Freeze-drying can noticeably improve the volume loading, and the impact of the drying method was more notable on poplar than on Chinese fir. The fixation effect of the B and P in poplar was lower by ultrasonic washing than that was by distilled water washing. The fixation effect was opposite in the Chinese fir. Vacuum process was more suitable for the poplar (hardwood), and vacuum-pressure process was
more suitable for the Chinese fir (soft wood).

WOOD RESEARCH Volume 65, Number 4, 2020
Hong Yun, Chuangshuang Hu, Jin Gu, Yilin Han, and Xiaojing Hu

Study on the permeation and fixation of ACQ-C in poplar

In this paper, the effects of atmospheric pressure, vacuum and vacuum pressure impregnation on the permeability of alkaline copper quat in poplar were studied, and the permeability and fixation of preservatives were improved by pretreatment of poplar. The results show that the volume loading of wood can be increased by about 60 – 150% after 30 min of vacuum treatment, so the vacuum method is a simple and efficient preservation treatment method. In addition, ethanol treatment, heat treatment and microwave treatment can increase the fixation rate of copper ions by 5 – 10%, but the fixation rate of copper ions dropped by 17.83% after NaOH treatment for the dissolution of partial hemicellulose.