Rigid polyurethane foams from unrefined crude glycerol – Study of crude glycerol composition

Rigid polyurethane foams from unrefined crude glycerol – Study of crude glycerol composition N. V. Gama1, R. Silva2, C. S. R. Freire1, A. Barros-Timmons1, A. Ferreira3 1 CICECO - Aveiro Instituto de Materiais andChemistryDepartmentofUniversityof Aveiro 2Sapec-Química SA, Ovar, Portugal 3 CICECO - Aveiro Instituto de Materiais and Escola Superior de Tecnologia e Gestão de Águeda

Outline • Introduction • What are polyurethanes; • Main applications; • Desirable properties of polyurethane foams; • Renewable feedstocks. • Experimental and results • Polyols used; • Preparation of foams; • Characterization of foams. • Main conclusions

Introduction Experimental Results Final Remarks Polyurethanes (PUs), also referred as urethanes, are polymers characterized by the urethane linkage. The linkage is formed by the reaction of NCO groups of isocyanate with OH groups of the polyol. Isocyanate Polyol Polyurethane Polyurethanes (PUs) are a class of polymers that find several important applications such: Adhesives Elastomers Paints Foams

Introduction Experimental Results Final Remarks Polyurethane foams (PUFs) are a class of lightweight porous materials with enormous interest due to their specific properties and potential application. Flexible foams Rigid foams Good mechanical properties Good thermal resistance Low thermal conductivity Low density

Introduction Experimental Results Final Remarks The production of PUs depends significantly on fossil reactants. The use of renewable reagents, in particular the replacement of the polyol, is increasing by the use of: Vegetable oils Biomass resources Industrial by-products Nuno V Gama, Belinda Soares, Carmen SR Freire, Rui Silva, Inês Brandão, C Pascoal Neto, Ana Barros-Timmons and Artur Ferreira. Polym. Int. 2015, 64, 250-257. Gama, N. V.; Soares, B.; Freire, C. S. R.; Silva, R.; Neto, C. P.; Barros-Timmons, A.; Ferreira, A. Mater. Des. 2015, 76, 77–85. Ferreira A.; Gama, N. V.; Soares, B.; Freire, C. S. R.; Barros-Timmons, A.; Brandão, I.; Silva, R.; Neto, C. P. ; Method for production of rigid polyurethane foams using unrefined crude glycerol. 107711 E, 2014

Introduction Experimental Results Final Remarks . The successful replacement of petrochemicals by CG in the PUFs production has the potential to reduce their cost and environmental impact. The composition of CG may vary in: • Glycerol; • Fatty acids; • Methyl esters; • Methanol; • Water content.

Introduction Experimental Results Final Remarks CGA 84.1% (w/w) of glycerol, 10.0% (w/w) of fatty acids, 5.9% (w/w) of methyl esters, Mw = 154.4 g/mol, Water content = 1.6% (w/w), OHnumber =399.0 mgKOH/g. CGT 98.2% (w/w) of glycerol, 0.6% (w/w) of fatty acids, 1.2% (w/w) of methyl esters, Mw of 97.8 g/mol, Water content = 1.6% (w/w), OHnumber = 497.7 mgKOH/g. 150 ºC, 60 min 4% (w/w) of sulfuric acid In a 70L pilot reactor CGB 60.1% (w/w) of glycerol, 21.3% (w/w) of fatty acids, 18.6% (w/w) of methyl esters, Mw = 163.8 g/mol, Water content = 0.4% (w/w), OHnumber= 323.4 mgKOH/g. GLY 99.5% purity, Mw = 92.1 g/mol, Water content = 0.1% (w/w), OHnumber = 520.9 mgKOH/g.

Introduction Experimental Results Final Remarks Crude Glycerol Isocyanate Catalyst Surfactant Polyurethane foam Blowing agent

Introduction Experimental Results Final Remarks Isocyanate used with a 20% of excess over the polyols. The methyl esters contributed to the presence of residual NCO groups.

Introduction Experimental Results Final Remarks The fatty acids and methyl esters affect the foaming process and the foam structure. PUF-CGA PUF-CGB Reference k value for PUFs - 0.033 W/mk PUF-CGT PUF-GLY Hu, S. & Li, Y. Polyols and polyurethane foams from acid-catalyzed biomass liquefaction by crude glycerol: Effects of crude glycerol impurities. Ind. Crops Prod. 57, 188–194 (2014).

Introduction Experimental Results Final Remarks The presence of fatty acids and methyl esters decreases the mechanical properties of PUFs. The higher OHnumber polyols leads to an increase of the chemical cross linkage density. The density, the morphology, the size or shape of the cells, plays a significant role in the mechanical properties of the foams. Hu, S. & Li, Y. Polyols and polyurethane foams from acid-catalyzed biomass liquefaction by crude glycerol: Effects of crude glycerol impurities. Ind. Crops Prod. 57, 188–194 (2014). Shufen, L., Zhi, J., Kaijun, Y., Shuqin, Y. & Chow, W. K. Studies on the Thermal Behavior of Polyurethanes. Polym. Plast. Technol. Eng. 45, 95–108 (2006).

Introduction Experimental Results Final Remarks The 20% of mass loss: PUF-CGA → T = 252.5 oC PUF-CGB → T = 240.4 oC PUF-CGT → T = 257.0 oC PUF-GLY → T = 262.6 oC Foams thermally stable up to 180 ºC Soft segments Hard segments

Introduction Experimental Results Final Remarks • The crude glycerol foams presented: • Low thermal conductivity; • Low density; • Good mechanical properties; • The crude glycerol foams are thermally stable up to 180 ºC • The presence of fatty acids and methyl esters in the CG has the effect of: • Decreases the mechanical properties of the foams; • Decreases the density of the foams; • Decreases the Tgs of the foams; • Decreases the thermal conductivity of the foams; • Decreases the thermal stability of the foams. Crude Glycerol, without any purification step or pre-treatment, is a renewable and a suitable ecopolyol for the production of PUFs

ACKNOWLEDGMENTS Financial Support GREENPEC – FCOMP-01-0124-FEDER-34132 This work was developed in the scope of the project CICECO-Aveiro Institute of Materials, financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement

Rigid polyurethane foams from unrefined crude glycerol – Study of crude glycerol composition