Preparation Of Intumescent Flame-retardant Coatings

The types and dosages of various matrix resins , flame-retardant system, dyes and fillers were filtrated in the thesis. The prescriptions of the experiments were preferably finished by orthogonal experiments and transverse comparing experiments. An intumescent flame-retardant coating was prepared using unsaturated polyester resin and epoxy resin as two-component matrix resins, common flame-retardant system—ammonium polyphosphate, melamine and pentaerythritol as flame-retardant assistants, expandable graphite as synergistic agent, by adding fillers titanium dioxide and corresponding assistants and solvent.The various important components influencing on the fire-endurance effect of the coatings were analyzed and discussed in detail in this article. The experiments indicate that the fire-endurance effect was consanguineously correlative with dosages of the matrix resins, flame-retardant system, expandable graphite and pigment-fillers. The optimal content of two-component matrix resins is about 28 percent and the content of unsaturated polyester resin is about 80 percent in matrix resins. The ratio and dosage of the three components in the flame-retardant system are the fatal factors which influence and determine the effect of fire-endurance. And the flame-retardant performance is optimal when the content of flame-retardant system gets 62 percent. The optimal ratio of APP, PER and Mel was 8:3:5. The optimal content of expandable graphite and titanium dioxide is 4 percent and 7.5 percent respectively.Differential Scanning Calorimentry (DSC) and Thermogravimetric Analysis (TGA) were used to contrastively analyze the various components' thermal characteristics of fire-retardant coating system. And the heating decompose processes and interactions of vary components are also discussed. The shapes and contribution of phosphorus to the formation of the final charred crusts and their morphological structures by Numeral-Photo, Scanning Electric Microscope (SEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Ray (FTIR). On this base, the formation of the final char-layers and the flame-retardant mechanisms of intumescent flame-retardant coating were systematically investigated.The limit time of fire-endurance of intumescent flame-retardant coating was measured by the simulative board-burning method. Comparing the measurement results with the national standards, it shows that such a coating is an excellent intumescent flame-retardant coating.