Physical properties and flame-retardant effects of polyurethane coatings containing pyrophosphoric lactone modified polyesters

Pyrophosphoric lactone modified polyester (PATT) containing two phosphorous functional groups in one unit structure was synthesized to prepare a non-toxic reactive flame-retardant coatings. Then the PATT was cured at room temperature with isocyanate, toluene diisocyanate-isocyanurate, to get a two-component polyurethane flame-retardant coatings (PIPUC). Comparing physical properties of the films of PIPUC with those of film of non-flame-retardant coatings, there was no deterioration observed in physical properties by the introduction of a flame-retarding component into the resin. We found that the char lengths measured by 45degrees Meckel burner method were 3.1 similar to 4.4 cm and LOI values recorded 27 similar to 30%. These results indicate that the coating prepared in this study is a good flame-retardant. The surface structure of coatings investigated with SEM does not show any defects and phase separation.