Synthesis of Bio-polyol from Vegetable Oils

Polyurethanes are used in many sectors such as textile, construction, automotive, medical, marine, electronics and etc. The raw materials used in the synthesis of polyurethane are generally petroleum-based chemicals. The price of petroluem is constantly increasing because petroleum is a limited non-renewable resource and this increase in petroluem prices causes a continuous increase in the prices of petroleum-based raw materials. In addition when global warming and sustainability issues are considered, increasing the use of renewable resources and the production of bio-based products have become a remarkable issue and research on these issues has increased considerably [1, 2, 3, 4].

The use of bio-polyols as a bio-based material in the synthesis of polyurethane is of great interest today. Vegetable oils such as rapeseed, sunflower, palm, coconut, linseed or soybean oil and even cooking oils are used as raw materials in the synthesis of bio-polyols [2, 5]. Hydrogenation, transesterification, epoxidation, ozonolysis, hydroformylation, metathesis and thiol-ene coupling methods are applied in the production of bio-polyols from vegetable oils as single-stage or multi-stage. The most preferred methods are epoxidation and transesterification methods among the existing studies [6, 7].

Properties of bio-polyols such as functionality, hydroxyl content, molecular weight, viscosity, ethylene oxide/propylene oxide content are important in determining the properties of polyurethanes obtained using bio-polyols. For example, the hydroxyl contents of bio-polyols cause differences in physical and mechanical properties of polyurethane and differ according to the synthesis method. The presence of secondary hydroxyl groups in the bio-polyol results in lower reactivity and larger cell size, while the presence of primary hydroxyl groups provides high reactivity, smaller homogeneously dispersed cell size and better thermal and mechanical properties [8, 9, 10]. Another important property of bio-polyols is functionality. The cross-link structure increases with the increase in functionality and as a result the glass transition temperature of the polyurethane product rises [10]. For this reason, the bio-polyol synthesis method and the raw materials should be carefully selected in order to provide the desired properties in polyurethanes produced from bio-polyol.

Evoco Polymer continues its R&D studies to expand its bio-based product range and to ensure a cleaner world for future generations.

References

1. Akindoyo, J. O., Beg, M., Ghazali, S., Islam, M. R., Jeyaratnam, N., & Yuvaraj, A. R. "Polyurethane types, synthesis and applications–a review.", Rsc Advances, 6.115 (2016): 114453-114482.

2. Konga, X., Liua, G., Qi, H., Curtis, J., M., “Preparation and characterization of high-solid polyurethane coating systems based on vegetable oil derived polyols”, Progress in Organic Coatings, 76 (2013) 1151–1160.

3. Hejna, A., Kirpluks, M., Kosmela, P., Cabulis, U., Haponiuk, J., Piszczyk, L., The influence of crude glycerol and castor oil-based polyol on the structure and performance of rigid polyurethane-polyisocyanurate foams, Industrial Crops and Products, Volume 95, Pages 113–125, 2017.

4. Cui, S., Liu, Z., Li, Y., Bio-polyols synthesized from crude glycerol and applications on polyurethane wood adhesives, Industrial Crops & Products, Volume 108, Pages 798–805, 2017.

5. Polaczek, K., Kuranska,M., Prociak, A., “Open-cell bio-polyurethane foams based on bio-polyols from used cooking oil”, Journal of Cleaner Production, Volume 359, 132107, 2022.

6. Chauke, N., P., Mukaya, H., E., Nkazi, D., B., “Chemical modifications of castor oil: A review”, Science Progress, Vol. 102(3) 199–217, 2019.

7. Maisonneuve, L., Chollet, G., Grau, E., Cramail, H., “Vegetable oils: a source of polyols for polyurethane materials”, EDP Sciences, 2016.

8. Kaikade, D., S., Sabnis, A., S., “Polyurethane foams from vegetable oil-based polyols: a review”, Polymer Bulletin, 2022.

9. Malani, R., S., Malshe, V., C., Thorat, B., N., “Polyols and polyurethanes from renewable sources: past, present and future—part 1: vegetable oils and lignocellulosic biomass”, J. Coat. Technol. Res., 19 (1) 201–222, 2022.

10. Campanella, A., L. M. Bonnaillie, and R. P. Wool. "Polyurethane foams from soyoil‐based polyols." Journal of Applied Polymer Science 112.4 (2009): 2567-2578.

Yazarlar: Beste Tatlıses                                                                                                      Tarih: Ağustos 2022