Study On Thermal Properties Of Intumescent Fire Retardant Coatings

At present,our country is still in the tide of basic hypothesis,and steel structure is more and more popular in engineering.Water-borne intumescent fire retardant coatings have been widely used in fire protection of steel structures due to their advantages of low toxicity,environmental friendliness and convenient construction.Under the action of fire,a series of thermophysical and chemical reactions will take place in the coatings.The thickness and thermophysical parameters of the coatings will change continuously.It is very difficult to calculate the temperature of steel components protected by hand coatings.This paper mainly completes the following work:(1)TG experiments were carried out on the selected waterborne intumescent fire retardant coatings,and DSC,TG and DTG curves related to temperature were obtained.On this basis,the fire protection mechanism,foaming and expansion process and formation process of carbon layer of waterborne intumescent fire retardant coatings were preliminarily analyzed.(2)The thermal expansion behavior of two kinds of fire-retardant coatings with different thickness under simulated fire standard was studied.The rule of the size of fire-retardant coatings varying with temperature from room temperature to 800 C was obtained.The relevant data laid a foundation for the subsequent study of the expansion model of fire-retardant coatings and the numerical simulation of heat insulation.(3)Based on the results of thermal conductivity analyzer,simultaneous thermal analyzer-mass spectrometer and thermal expansion behavior research,the basic test data which can be used to characterize the thermal conductivity,specific heat and density-temperature dependence of materials are obtained,and the mathematical model of thermal physical parameters changing with temperature is obtained by data fitting.(4)Based on the test results of thermal expansion behavior and thermal physical properties of fire-retardant coatings,a numerical model and calculation method for predicting the thermal insulation performance of fire-retardant coatings at high temperature were established,and the temperature rise calculation results of structures with fire-retardant coatings under typical fire conditions were obtained.