Main Article Content
The selectivity of tungstate-based catalyst in the epoxidation reaction of rubber seed oil and modified rubber seed oil was studied in two ways. The titration method was performed according to the ASTM standard and the H-NMR method was based on the peaks of the three different standard groups. The catalyst selectivity of the epoxidation reaction of modified rubber seed oil was much higher than that of non-modified rubber seed oil for both methods. The average catalyst selectivity obtained by using H-NMR method of the modified rubber seed oil epoxidation reaction was equal, while of the rubber seed oil epoxidation reaction was 11% lower than that of the titrimetric method. For both types of oils, the difference between the catalytic selectivity obtained by using titration method and by using protons in group α-CH2-(C=O)-O- as the standard peak was the smallest and was the biggest when the protons in group -CH3 was used as the standard peak.