EVALUATION OF PORE SPACE FORM OF INTUMESCENT FIRE RETARDANT COATING

Intumescent coatings when exposed to temperatures above 150 °C form porous substance with low thermal conductivity. The size and arrangement of pores affect the value of the thermal conductivity and, therefore, the parameters of fire retardant intumescent coating efficiency. The authors first examined the possibility of estimating the pore space coating using the Russian program “VideoTests”. Using this program it is possible to determine the thickness, and phase analysis of coatings, as well as an assessment of the pore space material and calculation parameters since stereological parameters of the structure. The researchers concluded that in order to achieve fire-resistance rating of more than 45 minutes in the pores fire protective coatings on acrylic resins with a diameter of 0.5–1 mm should not exceed 30 %, with a diameter of more than 2 mm — less than 3 %. Swelling ratio value should be placed in the range of 40–65, weight loss of the sample coverage for thermogravimetric analysis does not exceed 45 % at a temperature of 500 °C.