Function of silicon oil in the castor oil based rigid polyurethane foams

Rigid polyurethane foams are one of the most important cellular plastics. Castor oil was modified with glycerol to form the polyol and reacted with methyl diisocyanate and different proportions of silicon oil to achieve rigid polyurethane foam. Prepared foam was tested for its density and mechanical properties. It was found that compressive and flexural strength was improved with silicon oil content. The morphology of the resulted foams was also studied using scanning electron microscope, and it was observed that the cell size was reduced with silicon oil content, indicating a more dense and packed structure. With further increase in the silicon oil content, foam properties showed a slight decrease in value.