Following the procedure described by Abril-Milán et al. [11] (link) the acid number of SBF and SBFpolyol was determined. In order to ascertain the composition, a thoroughly mixed test sample (5 g for shea butter and 10 g for polyol) was placed within a 250-mL Erlenmeyer flask. The process entailed the consecutive addition of 50 mL of hot ethanol (EtOH) and 1 mL of a 1% phenolphthalein solution.
Afterwards, the combination was cooked on a hotplate until it reached its boiling point and then kept at that temperature for a duration of 5 minutes. Eventually, the flask was brought down, and the mixture was promptly titrated (while it was still hot) using 0.1M NaOH with vigorous stirring, until the moment when the transparent solution changed to a pink tint. The volume of 0.1M NaOH was used to calculate the acid value according to the provided formula:
V is the volume in ml of standard NaOH consumed, M is the molarity of the NaOH, and W is the weight of the sample.
Afterwards, the combination was cooked on a hotplate until it reached its boiling point and then kept at that temperature for a duration of 5 minutes. Eventually, the flask was brought down, and the mixture was promptly titrated (while it was still hot) using 0.1M NaOH with vigorous stirring, until the moment when the transparent solution changed to a pink tint. The volume of 0.1M NaOH was used to calculate the acid value according to the provided formula:
V is the volume in ml of standard NaOH consumed, M is the molarity of the NaOH, and W is the weight of the sample.
