Production of polyurethane from polyols obtained by vicynal diol of vegetable oils in KMnO4

In this study, the binding of hydroxyl end groups to the structures of unsaturated fatty acids was attempted in a one-step process from vegetable oils (castor oil, cottonseed oil, and safflower oil) and algae oil in the presence of KMnO4 by a vicinal dihydroxylation reaction. Vicinal diol treatment was studied at different times, temperatures and amounts of KMnO4. The C=C double bond structures of the obtained samples were analyzed by UV spectrometry, the hydroxyl values by titration and the chemical structures by Fourier transform infrared spectroscopy (FTIR). The hydroxyl numbers of the polyols obtained from castor oil, safflower oil, cottonseed oil, and algae oil were 255, 278, 75, and 256 mg KOH/g, respectively. The yields of the dihydroxylation reaction were 73.3%, 83%, 71% and 47% for safflower oil, algae oil, castor oil and cottonseed oil, respectively. The mechanical properties of the obtained polyurethanes were similar to those of commercial biopolyols.