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.

Flexible polyurethane foams synthesized employing recovered polyols from glycolysis: Physical and structural properties

“…As reported by other authors, 40 it can be observed in Figure 3 that an increase in the recovered polyol content causes an improvement in the tensile properties of the PU foams probably due to the higher crosslinking and higher urea formation. In fact, it can be observed that the foams synthesized with glycolyzates obtained employing DEG as cleavage agent show the highest values of tensile strength since these recovered polyols present the highest proportion of compounds that increase the crosslinking and the urea domains in the PU structure (glycolysis agent excess and byproducts).…”

“…In a general way, it can be observed that the foams preserve the polyhedral cell structure independently on the content of recovered 40 In fact, the higher the viscosity of the polyol mixture, the more restricted the CO 2 to be expanded, giving as a result a decreasing in the PU foam cell size. 40,45 Figure 6 shows the cell-size distribution of all synthesized foams.…”

“…However, crude glycerol promotes the reduction of the cell size, while when using DEG cell size increases with the amount of recovered product, regardless the kind of PU foam recycled. This can be explained attending to the different viscosities of glycerol (1412 cp at 20 °C) and DEG (35.7 cp at 20 °C) since foam cell size is a function of the mixture viscosity and of the CO 2 expandability . In fact, the higher the viscosity of the polyol mixture, the more restricted the CO 2 to be expanded, giving as a result a decreasing in the PU foam cell size .…”

Flexible polyurethane foam‐based sandwich composites: Preparation and evaluation of thermal, acoustic, and electromagnetic properties

“…CO 2 takes a large volume of the cell structure of PU foam as a result of the reaction of polyether polyol and isocyanate. CO 2 has a thermal conductivity coefficient of 0.0137 W (m −1 ·K −1 ), which is bottom than that of air 0.0233 W (m −1 ·K −1 ) . As a result, the LPET/FPU sandwich composites have a greater thermal retention property.…”

Optimization of acoustic performances of a new tung oleic acid‐based composite polyurethane foam

“…It is well known that the sound absorption characteristic of PU foams can be controlled by varying raw materials such as polyol, isocyanate, crosslinking agent, blowing agent, surfactant, catalysts, and any other additives. 29 The properties of PU can be developed by changing the ratio of these raw materials. The acoustic properties of materials include sound absorption and sound insulation.…”