Properties of rigid polyurethane foams synthesized from 4,4′-diphenylmethane diisocyanate and polyether polyol

Rigid polyurethane foams (PUFs) were prepared from polymeric 4,4′-diphenylmethane diisocyanate (PMDI), polyether polyol, 1,4-butane diol, silicone surfactant, and distilled water. The density of the PUF was decreased from 173.7 to 41.7 kg/m ³ with an increase in distilled water from 0.5 to 3.0 php (parts per hundred polyol by weight), respectively, at the 0 php butane diol. The cell size of the PUF increased from 115 to 258 μm with an increase in the amount of distilled water from 0.5 to 3.0 php, respectively, at the 10 php butane diol. It was found that the compressive strength of the PUF increased with the content of distilled water, at the same density. Out of the study for the surfactant effect on the properties of the PUF, it was observed that the cell size of the PUF decreased from 360 to 146 μm with an increase in the amount of the surfactant from 0 to 0.33 php, respectively, but the cell size did not change significantly when the amount of the surfactant exceeded 0.33 php.