Polyurethane foam (PUF) has been extensively used in many fields including LNG carriers because PUF made by synthesis of polyol and isocyanate has many advantageous characteristics such as low thermal conductivity, good mechanical properties, light weight etc. Mainly, PUF was used for the insulation between the tubes of a double insulated pipe used for the transfer of high or low temperature materials in LNG carriers. Also, in the marine industry, PUF was commonly used to insulate pipes, cargo containment system and LPG & LNG tank structure used for fluid storage and transport of LPG & LNG vessels.
In the present study, the investigation of thermal and mechanical characteristics of irradiated PUFs according to the irradiation dose under the various temperature conditions including low/cryogenic temperature. To investigate the effect of irradiation on PUF, a compression tests and measurement of the thermal conductivity of the irradiated PUF were performed using each testing equipment and investigated according to the irradiation dose in various environments. In addition, micro-structural investigation before and after the test was carried out to investigate the relationship between thermal and mechanical characteristics and irradiation dose. Accordingly, the test results were quantitatively presented, and it was found that the irradiated PUF has potential for application in industrial structures.
International Maritime Organization (IMO) tightened regulations on building the LNG carriers with the aim of reducing greenhouse gas emissions by 20 percent by 2020 and by 50 percent by 2050 from their 2005 level. Since the environmental regulation has been reinforced, the consumption of Liquefied Petroleum Gas (LPG) and Liquefied Natural Gas (LNG) is increasing faster than that of other available energy resources known to be less environmentally-friendly. Owing to the growth in global demand for LNG and LPG, there has been a drastic increase in LNG carriers. One of the most important components of these carriers is the cargo containment system, studies on PUF which is a cryogenic insulating material of membrane type cargo containment system of carriers for storage and transport have been actively conducted (Jang et al, 2013; Kim et al, 2014).