The Effect of Fire Retardants on the Fire Resistance of Unsaturated Polyester Resin Coating

Unsaturated polyester resins (UPRs) are most commonly used coating materials on steel among thermosetting polymers because of their low cost, easy application and good performance properties. However, UPRs show insufficient fire-resistance in respect of relatively high flammability accompanied by smoke production upon burning due to aromatic groups in the structure. Consequently, improving the fire retardancy of UPRs for extending their application becomes pivotal. Fire retardants (FRs) are widely used in polymers because they prolong the time to ignition, slow down the rate of flame spread, and generate less heat and smoke or toxic fume compared with the unmodified polymers. It has been a challenge to develop a cost effective, environmentally friendly fire retardant system which minimizes the negative effect on performance properties of the polymers [1 - 4].