Thermal studies on paper treated with flame-retardant

Sodium silicate and sodium berate mere tested as dame retardants on two types of paper sheet (100% rice straw pulp paper with a high silica content while the other consisted of 100% wood pulp paper). After addition of inorganic flame retardant salts (sodium silicate and sodium berate) on to the two samples of paper, the thermal behaviour of the treated paper sheets revealed differences in the course of the differential thermal analysis curves. The thermal analysis studies were carried out under an oxidizing atmosphere using differential thermal (DTA) and thermogravimetric (TGA) analysis, The flame retardants used in this study reduced the amount of volatile products formed during decomposition of the paper and increased the weight loss due to formation of char for the treated papers. The thermal degradation of paper can be considered as a first order degradation. Two stages of thermal degradation were kinetically differentiated, namely, a volatilization stage and a decarbonization stage, The activation energy for these two stages were calculated. The addition of flame-retarding salts decreased the activation energy for both stages, Sodium silicate salt showed more reduction of activation energy than sodium berate, especially for the rice straw paper. Copyright (C) 1999 John Wiley & Sons, Ltd.