GREEN ESTERIFIKASI DAN KETALISASI PADA PEMBUATAN ZAT ADITIF BIO-PELUMAS DARI ASAM OLEAT; GREEN ESTERIFICATION AND KETALIZATION IN THE SYNTHESIS OF BIO-LUBRICANT ADDITIVE FROM OLEIC ACID

Muslih Anwar, Tutik Dwi Wahyuningsih

2011 | Disertasi | PROGRAM STUDI S2 ILMU KIMIA

Synthesis of bio-lubricant additive from oleic acid using montmorillonite KSF as a heterogenous catalyst has been carried out. Oleic acid was oxidized by dilute potassium permanganate (KMnO4) in alkaline condition at 0-10 oC to give diol which was then reacted with ethanol under ultrasonic irradiation or reflux condition. Esterification reaction was conducted using montmorillonite KSF and sulphuric acid as catalysts. Ethyl 9,10- dihydroxystearate was reacted with cyclohexanone and acetone for 4 hours using montmorillonite KSF as a catalyst. Ketalization gave ketals that can be used as bio-lubricant additive. Every step of the reactions was evaluated with atom economy and eco-efficiency concept. The structure elucidation of the products was performed by FTIR spectrometer and GC-MS. The results showed that oxidation of oleic acid gave a 9,10-dihydroxystearic acid in 33.86 % yield. Esterification of 9,10-dihydroxystearic acid and ethanol catalyzed by sulphuric acid yielded 90.11 % and 84.30 % of ethyl 9,10- dihydroxystearic at reflux condition for 4 hours and ultrasonic medium, respectively. Atom economy and eco-efficiency evaluation of esterification gave the best result when montmorillonite KSF was used as a catalyst, i.e 52.32 % in yield. Furthermore, ketalization of ethyl 9,10-dihydroxystearate with cyclohexanon and acetone using montmorillonite KSF as catalysts gave 69.74 % and 53.30 % in yield, respectively. The products are yellowish liquid which can be used as additive in bio-lubricant.

Kata Kunci : asam 9,l0-dihidroksistearat, bio-pelumas, montmorilonit KSF, ketalisasi, atom ekonomi, eco-efficiency