Effects of a new GUP-B fire retardant on mechanical properties of Korean pine when exposed to elevated temperature

Abstract

The bending properties of Korean pine (Pinus koraiensis) treated with a newly formulated guanylurea phosphate (GUP) fire retardant were evaluated. The chemical processing method used to formulate this fire retardant(called FRW) results in an organic phosphate fire-retardant system with less acidic pH and fewer impurities. The fire-retardant chemical studied consisted of high purity GUP, boric acid (B), and a minor amount of additives. The clear specimens of pine treated with FRW were either air- dried after treatment or kiln-dried at 70°C and were then subjected to various durations of a steady-state exposure at 66°C and 75 percent relative humidity. No significant differences in thermal degradation between the untreated controls and the FRW-treated pine were found regardless of whether it was air-dried or kiln-dried after treatment. However, for other tested fire retardants with much lower pH values, kiln-redrying induced significantly more degradation compared with air-redried material. On exposure to elevated temperature, the strength and stiffness of FRW-treated Korean pine experienced deterioration, but the extent was less than that previously reported for other GUP-B formulations produced using different manufacturing processes. Because of its milder acidity which results from the modified manufacturing process, enhanced stability related to thermal degradation was noted for this enhanced GUP-B (FRW).

Citation

Wang, Qingwen; Wang, Weihong; Winandy, Jerrold E. 2005. Effects of a new GUP-B fire retardant on mechanical properties of Korean pine when exposed to elevated temperature. Forest products journal. Vol. 55, no. 12 (Dec. 2005): pages 214-220.