A study into the ultrasonic initiated alkaline hydrolysis of triglycerides (also known as the saponification reaction) is described. Sunflower oil is used as a source of triglycerides. The reaction is driven by the ultrasound from either an ultrasonic water bath (35 kHz-85 W) or a probe (40 kHz-50 W) in the presence of potassium hydroxide (KOH). It will be shown that ultrasound is effective as a power source to initiate and drive the reaction, that a high reaction yield is achievable in only 15 min of total power application while working at ambient temperature, and that no detectable by-products are generated during the reaction. Comparison of the two methods shows the ultrasonic probe to be the superior technique. Our method demonstrates reasonable yields can be obtained without the need for excess alkali or phase transfer catalysis. Curing the soap for several weeks allowed the saponification reaction to proceed to completion. Suggestions for a practical application have also been given.

We describe the ultrasonic initiated modification of four types of oil; sunflower oil, transformer oil, cable oil and silicone oil. Ultrasound is effective in initiating and driving reactions of the three hydrocarbon oils but ineffective in the case of silicone oil. The hydrocarbon oils showed noticeable reductions in viscosity after sonication; this reduction can be enhanced by incorporating nucleating agents such as particulate carbon. The viscosity loss is not permanent without using stabilisers and with time the viscosity approaches its initial value. The ultrasonic reaction is thought to be free radical in nature, since incorporation of a radical scavenger before sonication prevents any viscosity loss, whereas incorporation after sonication stabilises the drop in viscosity. Oxygen is proposed to be involved since purging with nitrogen diminishes any viscosity drop observed, and selected ion flow tube MS analysis of volatiles from the oils after sonication indicates an increase in the number and quantity of oxidised products.