The catalytic performances of POM–ILs were investigated in the esterification
of oleic acid with methanol (Table 1). The typical GC-MS
chromatograms of oleic acid sample before and after the esterification
reaction are shown in Fig. 2. The composition of the sample was oleic
acid (82.54 wt.%), myristic acid (3.54 wt.%), palmitic acid (6.17 wt.%),
palmitoleic acid (5.83 wt.%) and stearic acid (1.92 wt.%). The catalytic
activities were expressed as yields of esters. [MIMPS]PWand [QPS]PW
catalysts are more active than the others (Table 1).