Effects of polyols and various additives on polyurethane foam blown by distilled water

Polyurethane foam blown by CFCs has been widely used as insulator in various industries. But as these products deplete the ozone, people have attempted to develop new alternatives. So KOGAS had developed the PUF insulator blown by HCFC-141b and taken out a patent from Japan, Korea and France in 2000 year. But as HCFC-141b also depletes the ozone, KOGAS had developed the alternatives of HCFC-141b. Distilled water is one of the potential alternatives. Rigid polyurethane foams (PUFs) were prepared from polymeric 4,4-diphenylmethane diisocyanate (PMDI), polyether polyols, 1,4-butane diol, silicone surfactant, amine catalysts, and distilled water. The density of the PUF reduced from 173.7 up to 41.7 kg/m3 with an increasing distilled water content from 0.5 up to 3.0 php (parts per hundred polyol by weight) at 0 php butane diol. The results of a study on the effect of additives on the properties of the PUF showed that the cell size of the PUF reduced from 360 to 146 μm as an increasing surfactant amount from 0 to 0.33 php, but the cell size did not change significantly when the amount of the surfactant exceeded 0.33 php. The reactivity on forming PUF increased with increasing catalyst and water content. Blowing catalyst promoted the blowing reaction, and gelling catalyst promoted the gelling reaction. The density and compressive strength of the PUF increased with increasing OH value and polyol functionality, but flexural strength did not always follow the same pattern.