The general procedure for the synthesis of propyl dodecanoate from n-propanol and vinyl laurate is as follows: enzymatic synthesis in a 50 mL high pressure reactor. The reactor was equipped with a pressure reading controller and a JASCO-PU-2080-CO2 plus regulator. First, a predetermined amount of vinyl laurate was added to the reactor, followed by a predetermined amount of n-propanol. Next, a fixed amount of PVA/CHI lipase was added to initiate the reaction, followed by sealing the reactor and assembling it into an SC-CO2 high pressure reaction system. Liquid SC-CO2 was pumped into the reactor at a flow rate of 3.5 mL/min. The reaction was carried out for a predetermined time at a specific pressure (MPa) and temperature (°C) set by the RSM software. Upon completion of the reaction, the SC-CO2 pressure was slowly released through a 50°C thermostatic limiter to allow the residual material inside the reactor to flow out with the CO2. The reaction products were subsequently analyzed by Perkin-Elmer Clarus-400 gas chromatography (GC) equipped with a flame ionization detector (FID) and a capillary column.The oven temperature program for the GC was to maintain an initial temperature of 90 °C for 4 min, and then increase the temperature at a rate of 10 °C/min to 240 °C. The GC was then operated at a constant temperature of 50 °C, and the temperature was increased by a Shimadzu QC. In addition, the products were further confirmed by gas chromatography-mass spectrometry (GC-MS) on a Shimadzu QP-2010 instrument.
