Ismat A. Abu-Isa

Intumescent Thermoplastic Elastomer Fire Shield Material

The intumescent material described in this paper expands under high heat or fire conditions to form an insulating sponge. Its composition is based on a blend of high-density polyethylene and chlorinated polyethylene. The material is processed using normal plastic techniques. Tensile properties, heat aging, fluid aging, and thermal properties have been evaluated and are presented. Fire testing using a 1000 °C Bunsen burner as a source, showed that the material does not drip or burn through, even after 30 minutes of exposure. Prototype fire shields made of the intumescent material have been tested on fuel tanks, bulkheads, and wheel well covers. In all cases the intumescent material provided excellent protection. Similar applications are identified for airplanes, motorcycles, industrial and residential buildings. The material is recyclable and can be made from recycled polymers.

Effects of methanol/gasoline mixtures on elastomers

The effects of methanol/gasoline mixtures on swell properties and tensile properties of selected automotive elastomers were investigated. Two gasolines with aromatic contents of 30% and 50% were used in the investigation. Equilibrium swell measurements and tensile measurements were conducted using ASTM standard procedures. The results show that although few elastomers were affected drastically by pure gasoline (e.g. natural rubber) and a few by methanol (e.g. fluorocarbon elastomer) most of the elastomers were more severely affected by mixtures of the gasoline and methanol rather than the pure components. Presence of higher aromatic content in the methanol/gasoline mixtures led to additional deterioration of properties. The data on all elastomers except the fluorocarbon can be explained in terms of the solubility parameter concept. Ultimate tensile and ultimate elongation values of elastomer networks were found to be quantitatively related by simple linear equations to the volume fraction of rubber in the swelled networks. They were also found to fit equations derived for equilibrium stressstrain relationships.