Synthesis and performance of flame retardant additives based on cyclodiphosph(V)azane of sulfaguanidine,1,3-di-[N/-2-pyrimidinylsulfanilamide]-2, 2, 2.4, 4, 4-hexachlorocyclodiphosph(V)azane and 1,3-di-[N/-2-pyrimidinylsulfanilamide]-2, 4-di[aminoacetic acid]-2, 4-dichlorocyclodiphosph(V)azane incorporated into polyurethane varnish

Abstract

Cyclophosphazenes and their polymeric products are some of the oldest and best known class of nitrogen and phosphor containing compounds. In recent years there has been considerable interest in the phosphazene-based family of materials due to the wide range of thermal and chemical stabilities associated with them. In addition, these materials are capable of imparting flame-retardant properties when incorporated into polymers and their composites. Flame retardants can be incorporated into polymeric materials either as additives or as reactive materials. Additive type flame retardants are widely used by means of blending them with a specific polymeric material. In this particular research, cyclodiphosph(V)azane of sulfaguanidine,1, 3-di-[N/-2-pyrimidinylsulfanilamide]-2, 2, 2.4, 4, 4-hexachlorocyclodiphosph(V)azane and 1, 3-di-[N/-2-pyrimidinylsulfanilamide]-2, 4-di[aminoacetic acid]-2, 4-dichlorocyclodiphosph(V)azane were synthesized for use as flame retardant additives with polyurethane varnish. These additives are physically incorporated into the polyurethane varnish formula. Experimental coatings were manufactured on a laboratory scale and applied by brush on wood and steel panels. The fire retardant ability of each coating type was characterized using the limiting oxygen index (LOI) test. The mechanical properties of these flame retardants were also examined to evaluate the drawbacks of the additives. Results of the LOI indicated that coating with these compounds containing chlorine, nitrogen and phosphorus exhibit a very good retardant effect, when blended with polyurethane varnish. Cyclodiphosph(V)azane of 1,3-di-[N/-2-pyrimidinylsulfanilamide]-2, 2, 2.4, 4, 4-hexachlorocyclodiphosph(V)azane showed the best flame retardant and mechanical properties of the additives investigated.