Thermal analysis of Pinus sylvestris L. wood samples treated with a new gel–mineral mixture of short- and long-term fire retardants

The aim of this paper is to assess the effectiveness of a new fire retardant mixture, which consists of a short-term (gel) and a long-term (carbonate mineral) fire retardant. Its thermal degradation behaviour was examined on Pinus sylvestris L. wood and compared to three known fire retardant products alone (DAP (NH4)2HPO4, sodium polyacrylate and huntite/hydromagnesite in a commercial form). Thermal analysis (TG and DTG) was employed for accurate screening of the samples’ flammability properties. The results indicate that the proposed mixture of a gel (sodium polyacrylate) and a carbonate mineral (huntite/hydromagnesite) leads to improved fire retarding efficiency for wooden materials by combining water insulation and chemical retardation, thus decreasing mass loss rate and increasing char production.