Hydrolytically Stable Organophosphorus Cellulose Reactants

Abstract

The N-hydroxymethyl derivatives of polycarbamates containing phosphorus in dialkylphosphonate and phosphine oxide structures were prepared. Their effectiveness as flame retardants for cellulosic substrates was evaluated and compared with that of a corresponding polycarboxamide. Under the application conditions investigated, the poly- carbamate and polycarboxamide derivatives react in high yield with cellulosic hydroxyl groups, but do not co-condense with the melamine derivative used as a source of additional nitrogen. Thus, the N-hydroxymethyl derivatives of these organophosphorus compounds and melamine can be employed in any desired ratio to study flame retarding effectiveness. The cellulose ethers obtained by reacting cotton with a com bination of trimethylol melamine and a tricarbamate derived from tris (hydroxymethyl) phosphine oxide or a correspond ing tricarboxamide withstand multiple launderings with little or no decrease in flame resistance. The sequence ot in solubilization of the polymethylol melamine and organophosphorus compounds was found to have a pronounced effect on the degree of flame resistance obtained.