Intumescent Material Passive Fire Protection Technique for Aircraft Engine Nacelle

Intumescent coatings can provide passive fire resistance at low cost and weight. These systems however intumesce at relatively low temperature and are not appropriate for certain applications. Specially, aircraft engine nacelle temperatures and the potential for fuel/fluid fed fires require higher intumescence temperatures than current systems can supply. Vermiculite based coatings intumesce because the waters of hydration boil, causing swelling and char formation. We propose to replace the waters of hydration with high boiling point (to 752F) organics through an ion-dipole bonding method developed and proven at TX State for similar clays. The product will be a granular powder additive that can be added to paint carrier resins to form a coating that intumesces at temperatures >700F. In Phase I two JSF qualified resins (epoxy and BMI) and a commercial intumescent coating resin will be used as carriers to demonstrate high temperature intumescence on graphite epoxy substrates. The micronized vermiculite and treatment chemicals are COTS commodity materials, and modified vermiculite costs will be within 2x of current additives, adding about 15% over current intumescent coating costs. The market for higher temperature intumescents is broad – there are applications in aerospace, chemical, oil, and automotive industries. By aligning with one of the world’s largest makers of intumescent coatings SMRC intends to work this product into standard commercial intumescent coating lines.