Optimization study of alkyl polyglycoside C12 synthesis using indirect method

Alkyl polyglycosides (APGs) are classified as non-ionic and green surfactants that can be synthesized from renewable materials such as glucose and fatty alcohol. APGs are commonly applied as surfactants in enhancing oil recovery (EOR) since APGs exhibit excellent interfacial activities, emulsified abilities, foaming performance, and wettabilities. In this research, the mixture of APG C12 was synthesized following the indirect method, which was consisted of two stages, i.e. butanolysis and transacetalization. Butanolysis was carried out by reacting glucose in technical grade with 1-butanol (1:2.8, m/m) and PTSA catalyst 1 mol% at 106°C for 6h. The mixture of APG C4 from butanolysis then was further applied in transacetalization without purification by adding 1-dodecanol with some optimizations, i.e. mass ratio of 1-dodecanol, reaction time, and temperature. The optimum condition to afford the APG C12 mixture was the mass ratio of glucose in technical grade and 1-dodecanol 1:7.5 m/m with PTSA catalyst 0.5 mol% at 115°C for 4h. All the mixture of APGs were analyzed for its remaining reducing sugar level using Benedict's test and further characterized using FTIR, UV-Vis, and LC-MS/MS. Moreover, physical characteristic tests such as compatibility, emulsion stability, solubility, and interfacial tension tests were also conducted on all the mixture of APGs. This study reveals that APGs can be synthesized using the indirect method with moderate to good physical characteristics which can be used for EOR surfactant for further application.