Structural foam Structural foam Sulfones are amorphous engineering thermoplastics noted for high heat-deflection temperatures and outstanding dimensional stability. These materials are claimed to offer the highest performance profiles of any thermoplastics processible on conventional screw-injection and extrusion machinery. Continuous use in air or in steam at rated temperature does not cloud, craze, or otherwise destroy their transparency.
Heat resistance is the outstanding performance characteristic of the sulfones.
A high percentage of physical, mechanical, and electrical properties is maintained at elevated temperatures, within limits defined by the heat-deflection temperatures. The strength and stiffness of PSU and PES are virtually unaffected up to their glass-transition temperature. For example, the flexural modulus of molded parts remains above 300,000 psi at service temperatures as high as 320T. Even after prolonged exposure to such temperatures, the resins do not discolor or degrade. Thermal stability and oxidation resistance are excellent at service temperatures well. Heat aging of the polymers increases tensile strength, beat-deflection temperature, and modulus of elasticity appreciably.