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Polyurethane foam (PUF) has generally been used in liquefied natural gas (LNG) carrier cargo containment systems (CCSs) owing to its excellent mechanical and thermal properties over a wide range of temperatures. An LNG CCS must be designed to withstand extreme environmental conditions. However, as the insulation material for LNGC CCSs, PUF has two major limitations: its strength and thermal conductivity. In the present study, PUFs were synthesized with various weight percentages of porous silica aerogel to reinforce the characteristics of PUF used in LNG carrier insulation systems. To evaluate the mechanical strength of the PUF-silica aerogel composites considering LNG loading/unloading environmental conditions, compressive tests were conducted at room temperature (20 °C) and a cryogenic temperature (−163 °C). In addition, the thermal insulation performance and cellular structure were identified to analyze the effects of silica aerogels on cell morphology. The cell morphology of PUF-silica aerogel composites was relatively homogeneous, and the cell shape remained closed at 1 wt.% in comparison to the other concentrations. As a result, the mechanical and thermal properties were significantly improved by the addition of 1 wt.% silica aerogel to the PUF. The mechanical properties were reduced by increasing the silica aerogel content to 3 wt.% and 5 wt.%, mainly because of the pores generated on the surface of the composites.

In this study, glass bubble (GB) is added to polyurethane (PU) foams at different weight ratios—0, 0.25, 0.5, 0.75, and 1 wt% —to investigate the changes in the mechanical and thermal properties of the foam. By conducting several tests and measurements, the density, cell morphology, compressive strength, and thermal conductivity of the foam are studied. In particular, the effect of GB additives is examined by conducting compression tests at various temperatures (−163, −100, −40, and 20°C). Scanning electron microscopy and X‐ray microscope reveal that the foams exhibit higher stability below 0.5 wt%, which improves the thermal performance. On the other hand, the compressive strength of the foams increases for all weight ratios of GB, and it increases sharply at 0.75 wt%. In addition, the chemical interactions and the dispersion of additives in the PU matrix are investigated through Fourier transform infrared and X‐ray diffractions analysis. It is found that the synthesis of PU foams with GB nanoparticles is an efficient method for improving the mechanical properties and insulation performance of the foam for LNG insulation technology.

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