THE SYNTHESIS OF IMIDAZOLIUM BROMIDE AND IMIDAZOLIUM ACETATE DERIVATIVES IONIC LIQUIDS AS MEDIUM IN CELLULOSE HYDROLYSIS BY CELLULASE

• Main Author: YOGI SAPUTRA (NIM:20517002) , MUHAMMAD
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/29365
• Institution: Institut Teknologi Bandung

Cellulose is one of abundant renewable polymer and is widely present in plant biomass. The <br /> <br /> crystalline structure of cellulose is formed by the intermolecular and intramolecular hydrogen <br /> <br /> bonds causes cellulose more difficult to be hydrolyzed into sugars. Pre-treatments of <br /> <br /> cellulose to decrease the degree of crystallinity cellulose were performed by using ionic <br /> <br /> liquid, therefore this research shows imidazole derivatives ionic liquid that can be used as <br /> <br /> medium in cellulose hydrolysis. The ionic liquids were synthesized from the reaction <br /> <br /> between 1-methylimidazole with two of alkyl halides, 1-bromodecane and 1-bromododecane <br /> <br /> utilizing Microwave Assisted Organic Synthesis (MAOS) method. The synthesis of ionic <br /> <br /> liquids were performed at 50 °C for 60 minutes using microwave irradiation power of 300 <br /> <br /> watt to give 1-decyl-3-methylimidazolium bromide ([DMIM]Br) and 1-dodecyl-3- <br /> <br /> methylimidazolium bromide ([DDMIM]Br) with 57.91% and 47.59% yield, respectively. The <br /> <br /> ionic liquid products were characterized by FTIR and NMR spectroscopy. The 1-decyl-3- <br /> <br /> methylimidazolium acetate ([DMIM]OAc) and 1-dodecyl-3-methylimidazolium acetate <br /> <br /> ([DDMIM]OAc) were synthesized by metathesis of ionic liquids [DMIM]Br and <br /> <br /> [DDMIM]Br with potassium acetate salt. The synthesis of ionic liquids were performed at <br /> <br /> room temperature for 1 hours to give [DMIM]OAc and [DDMIM]OAc with 70.34% and <br /> <br /> 69.98% yield, respectively. The ionic liquids produced from the metathesis reaction were <br /> <br /> characterized by FTIR and NMR spectroscopy. The treated cellulose in all four ionic liquids <br /> <br /> and microwave heating were subsequently characterized by FTIR spectroscopy and XRD <br /> <br /> analysis, which showed a decrease in the degree of crystallinity in cellulose. Reducing sugars <br /> <br /> content by the DNS analysis indicated that the cellulose treated in each ionic liquids <br /> <br /> imidazolium bromide and imidazolium acetate derivatives with microwave heating have a <br /> <br /> significant increased, which is in the range of 79.115 – 82.665 mM and 80.065 – 89.349 mM <br /> <br /> of reducing sugars. Reducing sugars content after dissolution cellulose in each ionic liquids <br /> <br /> imidazolium bromide and imidazolium acetate derivatives as medium and co-solvents were <br /> <br /> decreased, which is in the range of 10.562 – 38.191 mM and 14.082 – 38.458 mM of <br /> <br /> reducing sugar. The results showed that the enzymatic hydrolysis of cellulose using cellulase <br /> <br /> performed more effectively if the cellulose is treated with ionic liquids and microwave <br /> <br /> irradiation