A water-insoluble amine-aldehyde copolymer intumescent agent having a number average molecular weight of about 350-2000 and consisting essentially of repeating units corresponding to the formula: ##SPC1## Wherein Q is the aldehyde residue and R is hydrogen, alkyl, haloalkyl, alkoxy, haloalkoxy, halo, nitro, acetamido, or sulfonamido is mixed with about 10-100% by weight of 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane as a synergist to increase the foam volume obtainable from the intumescent agent. The compositions comprising the intumescent agent and synergist may be applied to substrates by conventional techniques.
An improved flame and fire retardant composition is obtained by reacting the appropriate ingredients in liquid form, drying the product to cake form and pulverizing to obtain a fire and heat retardant powder. This powdered form is advantageous in that it may be readily handled and may be associated or used with fire unstable materials that would be adversely affected by a liquid composition. The powdered form has a low bulk density and can thus create economies in the weight of material used to provide effective fire and heat retardant properties.