Eskisehir, Turkey – Various agricultural wastes are being explored as potential sources of biomass for manufacturing polymers, and scientists at the Eskisehir Technical University have looked into the potential of making biopolyols from sugar beet pulp.
They used an acid-catalysed solvothermal liquefaction method to create polyols from the sugar beet residue, and then used these to manufacture several rigid PU foams, replacing the fossil-based polyol with various different proportions of biopolyol.
The effects of the introduction of the biopolyol on the foam’s morphology, and physico-mechanical, thermal and flame retardant properties were all evaluated.
The cell windows opened with increasing biopolyol content, and the decrease in closed cells was also determined. The insulation properties of the foam containing up to 40% biopolyol were superior, and the mechanical properties at 20% were higher. Its high porosity showed a significant increase in water absorption. All were thermally stable up to 247°C, but the flame retardant properties were not satisfactory, as adding biopolyol increased smoke production and heat release rate; flame retardants would have to be added.
The work has been published in the journal Industrial Crops and Products.