Investigation on Properties of Water and Methylene Chloride Blown Rigid Polyurethane Foam

Abstract

Physical properties are important parameters which influence the other properties and performance of rigid polyurethane foam (RPUF). Water and methylene chloride are the important ingredients of RPUF which act as blowing agents and influence the density, morphology and fire properties. RPUF samples were prepared from crude 4, 4’-diphenylmethane diisocyanate (CMDI), polyether polyol, triethylene diamine (TED), 1, 4-butane diol, polysiloxane ether, water and methylene chloride. RPUF with different densities were prepared by varying the amount of water and methylene chloride. This investigation reports the density, morphology and fire properties of RPUF varying with water and methylene chloride contents. The density of RPUF samples blown by water, methylene chloride and mixture of water and methylene chloride was ranged from 240.1 to 33.4 kg/m3 with an increase of water and methylene chloride contents. The cell morphology of the RPUF samples was investigated with scanning electron microscopy (SEM). SEM results exhibit the average increase in the cell size of the RPUF samples from 162 to 278 m with the increased water and methylene chloride contents. The fire properties results indicated that extent burnt and percent mass loss (PML) were unchanged however, burning rate decreases and burning time increases as the density increased. The increasing quantity of water increases the burning rate and decreases the burning time but does not have any effect on the extent burnt and PML of RPUF samples. Thus some important properties such as density, cell morphology and fire properties are directly affected by water contents.