EFFECTIVENESS OF MICROWAVE-SOAKING ASSISTED IMPREGNATION OF TEAK WOOD (Tectona grandis Linn. f) WITH SULFUR-CONTAINING AMMONIUM SALT AS FIRE RETARDANT

Abstract

The objective of this study is to investigate the use of microwave-soaking combination methods to improve the impregnation efficiency of Ammonium Sulfate (AS) as a fire-retardant into the teak wood. Various methods were compared by testing the (WPG). Experiments were performed for different impregnation conditions such as microwave power, radiation time and soaking time. The results showed the optimum condition for maximum WPG with microwave was to impregnate with AS solution using microwave power of 300 W, with a radiation time of 10 min, and then soaking at 75ºC for 6 hours. The effect on the properties of the treated wood before and after microwave-soaking treatment was also investigated by Fourier Transform Infrared Spectroscopy and compression strength parallel to the grain. Furthermore, this work evaluated the effect of AS contents having a concentration of 0-25 wt.% impregnated into teak on flammability and leachability. Flammability was tested using the Limiting Oxygen Index (LOI) and, leachability was carried out according to JIS K 1571. The test indicated that the LOI values increased from 21.24% for untreated wood to 38.5 for 25 wt.% AS as a self-extinguishable wood, and the leaching of AS from wood was in the range 1-2.5%, indicating the good fixation of AS in teak.

Keywords

• Ammonium sulfate
• Compression strength
• Fire retardancy
• Leachability
• Limiting oxygen index
• Teak wood.