Reduced Flammability Vinyl Ester Resin Containing no Halogens for Use in Large Composite Ship Surface Structures via Nanocomposite Technology

"The objective of this research is to further develop, optimize and scale up a halogen free nanocomposite vinyl ester system that will provide low flammability composites. The nanocomposite system proposed will be based on commercially available vinylester resins and thus should not result in a significant increase to raw material costs. Layered silicate based nanocomposites are a relatively new class of materials with properties that are unattainable with conventional microscale reinforcements. Infact, even at low concentrations layered silicates have been shown to provide an increase in modulus, heat distortion temperature, impact strength and fire retardance. One of the key drawbacks in these systems is a dramatic increase in viscosity when thesilicate is well dispersed. This viscosity increase negates the ease of processability for void-free composites that is key to the utilization of vinyl esters in many composite applications. For this reason, one main thrust of this proposal will be tointroduce the dispersed silicate reinforcements into the vinyl ester in such a way as to preserve the ease of processability.BENEFITS: Vinyl ester resins are important matrix resins for thermoset polymer matrix composites. The low room temperatureviscosities of the vinyl ester - styrene mixtures coupled with tailorable cure schedules, low cost and excellent mechanical properties make them prime candidates for composites in transportation, infrastructure and marine applications. Flame retardantvinyl ester composites are currently utilized by the Navy as well as in many private industry products. In fact, of the 60 million lbs. of vinyl ester sold into the North American market in 2000, 10% (6 million lbs.) were flame retardant with an annualgrowth rate of 4%. The current flame retardant technology is dependant on brominated resins. The bromine content provides for a lower heat release, however smoke generation is high and the carbon monoxide generation is even higher than in non-halogenatedresins. Another disadvantage of the brominated sys