Abstract: The oxidation modification of wax through free radical chain reaction initiated by lauryl hydrogen peroxide under relative mild conditions was studied using 58# fully-refined paraffin wax as raw material, air as oxidant and lauryl as initiator. The effect of reaction temperature and time, the amount of the initiator and the air flow on the acid number and saponification value of the oxidized wax were investigated. The results showed that at the optimized reaction conditions of a temperature of 130 ℃, a reaction time of 6 h, a initiator amount of 0.5%, and a air flow of 220 mL/min, the acid mumber and saponification value of the oxidized product were 40.5 mgKOH/g and 65.3 mgKOH/g, respectively. The binary system consisted of 0.8% oxidized product and 1.2% sodium hydroxide used for oil-displacing system had an interfacial tension of 2.9×10-3 mN/m with crude oil, and the oil removal rate at the surface of sandstone was 61.0%, indicating the excellent oil-water interface properties of paraffin oxidation product.

Key words: oxidized wax, lauroyl hydrogen peroxide, acid number, saponification value, interfacial tension, oil removal rate