POLYURETHANE RIGID FOAM, A PROVEN THERMAL INSULATING MATERIAL FOR APPLICATIONS BETWEEN -196(DEGREES)C(130(DEGREES)C AND )

Polyurethanes are high molecular weight polymers based on the polyaddi tion of polyfunctional hydroxyl-group containing compounds and polyiso cyanates. A wide variety of properties can be tailored to fulfil the r equirements of different applications: soft to hard, plastic, elastic or thermoset, compact or foamed.Compared with other insulating materia ls, PUR rigid foam is highly competitive. There are five product relat ed advantages: lowest thermal conductivity, high mechanical and chemic al properties at both high and low temperatures, all major internation al fire safety requirements can be satisfied, the ability to form sand wich structures with various facer materials, and the new generation o f PUR is CFC-free and recyclable. Rigid polyurethane foams perform wel l in most areas of low-temperature Insulations. Products in density ra nging from approximately 30 to 200 kg m(-3) withstand temperatures dow n to -196 degrees C. Typical applications are: refrigerated vehicles, road and rail tankers, vessels for refrigerated cargo, pipelines, liqu id gas tanks for LPG and LNG and cryogenic wind tunnels. The paper pre sents applications, corresponding properties of the rigid foams used, and also other insulating materials in competition to PUR are discusse d. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.