Influence of Recycled Polyurethane Polyol on the Properties of Flexible Polyurethane Foams

Abstract

Flexible PU foam was synthesized by using recycled PU foam polyol (Infrigreen) which contain 4 functionality obtained from glycolysis wasted PU foam, as a polyol. PU foam is prepared by incorporation of recycled PU foam polyol 2, 4, 6, 8 and 10wt% in petrochemical polyol (CARADOL.SA34-05) which contain 2 functionality. Triethlylenediamine (TEGOAMIN 33) was used as the gelling catalyst. Polyether modified polysiloxane (TPGAOSTAB B8715 LF2) was the surfactant. Distilled water was used as a blowing agent to generate foam. Polymeric methylenediphenyl diisocyanate (pMDI) which contain 2.7 isocyanate groups/molecule was used for generate urethane linkage and carbon dioxide. The parameters investigated are characteristic time, i.e. cream time, gel time, rise time and tack free time, cell structure and cell morphology, tensile properties, compressive properties and compression set were compared with petrochemical based PU foam. It was found from the research that, cream time, gel time, rise time and tack free time, decrease with the recycled PU foam polyol content. It was also found that the incorporation of recycled PU foam polyol led to the increase in smaller cell size and large distribution of cell size. Tensile properties and compressive properties of PU foam increase with polyol functionality, including crosslink density and urea formation in PU foam. Decreasing of shape recover properties of PU foam obtained at high recycled PU foam polyol contents. This was caused by the deformation of hydrogen bonding between hard segments of PU chains. These results indicate that tensile properties and compressive properties of PU foam enhance by incorporation of recycled PU foam polyol.