Synthesis And Properties Of Intumescent Transparent Fire Retardant Coating

To maintain the original appearance of wood structure, the ancient buildingsurface fire protection coating material must be transparent, fire resistant, and crackresistant. Currently, the transparent fire-resistant coating mainly prepared fromurea-formaldehyde resins, melamine formaldehyde resins, and phosphate esters. Fireperformance of such coatings was good. But the flexibility and crack resistance werepoor because of the high cross-linking density.In this paper, polyphosphate with flexible segments, silane modified polyphosphate were synthesized. These polymers cooperated with amino resin to givetransparent expandable fire retardant coatings. The impact of the structure of thesepolymers on the flame resistance, flexibility, crack resistance were studied. This willprovide new ideas for development of high performance transparent fireproofcoating material.First, phosphate resins were synthesized from poly phosphoric acid, polyol anddifferent length of PEG. Blending of phosphate resin and methyl etherificationmelamine formaldehyde resin formulated an intumescent transparent fireproofvarnish. Through FTIR, TGA, hardness, flexibility, digital photos, SEM and othertesting methods, it was shown that the introduction of PEG chain can effectivelyimprove the flexibility of the coating. The longer the chain length, the better theflexibility and resistance to cracking, but the too long chain length will reduce theflame retardant performance accordingly.Then, we accessed organic silane in polyphosphate to got silane modifiedtransparent coating. The results showed that the introduction of silane can effectivelyimprove the flexibility and flame retardant of the coating. The charcoal layerstructure was more compact than before and no collapse after long time burning.