Sinteza poliolilor prin oxipropilarea celulozei pentru producția de spume de poliuretan

Abstract

This study investigates the synthesis of polyol from the oxypropylation of cellulose, with the objective of producing more sustainable polyurethane (PU) foams. The oxypropylation was carried out using cellulose fibers treated with Brønsted bases (KOH and LiOH) and propylene oxide, varying the temperature (130 °C and 165 °C). The polyol samples obtained were characterized by their hydroxyl index (IOH), which ranged from 574.87 to 709.58 mg KOH/g. The results showed that the higher temperature (165 °C) favored an increase in the number of -OH groups, especially with LiOH as the catalyst. The PU foams were synthesized from the modified polyol and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Shore A hardness, and Thermogravimetric (TG). FTIR spectroscopy confirmed the presence of the characteristic PU groups, such as -NH, C=O, C-N, and C-O, while the Shore A hardness values indicated a higher hardness than that of the control sample, suggesting an increased crosslinking of the sample. The TG data revealed a reduction in the thermal stability of the foams synthesized with the modified polyol. The results indicate that the use of cellulose-derived polyol may replace petrochemical polyol, offering a more sustainable alternative for the production of PU foams.