Cryogenic characteristics of chopped glass fiber reinforced polyurethane foam

Liquefied natural gas (LNG) is mainly carried by membrane type LNG ships, whose cargo containment system is composed of dual tightness barriers and two insulation boards. The insulation board should have not only cryogenic reliability against thermal load, but also high thermal insulation performance for safe and efficient transportation of LNG. Although polyurethane foam (PUF) has been widely used for the insulation board due to its low production cost and relatively good thermal and mechanical properties, the cryogenic reliability of PUF is a remaining concern in marine fields due to its brittleness at cryogenic temperatures. In this work, the PUF was reinforced with chopped E-glass fiber because of its good dispersion and distribution characteristics. The compression, tension and the fracture toughness test were conducted with respect to the amount of the chopped E-glass fiber both at the room (25 °C) and cryogenic (−150 °C) temperatures. From the experimental results, it was found that the chopped E-glass fiber reinforcement increased the fracture toughness of the PUF much, especially at the cryogenic temperature. Therefore, the PUF reinforced with chopped glass fibers will improve much the reliability of the LNG cryogenic containment system during the voyage of LNG ships.