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[Gliserol merupakan senyawa alkohol yang memiliki tiga buah gugus hidroksil(-OH) sehingga dapat direaksikan dengan suatu asam karboksilat membentukester. Salah satu senyawa yang termasuk ke dalam karboksilat adalah asamp-hidroksi benzoat yang juga merupakan senyawa fenolik. Cairan ionik dikenalsebagai pelarut dan katalis yang ramah lingkungan dalam penggunaannya untukberbegai senyawa. Pada penelitian ini dilakukan reaksi esterifikasi asamp-hidroksi benzoat dengan gliserol menggunakan dua jenis katalis yaitu cairanionik, 1-Butil-3-Metil Imidazolium Klorida [BMIM]Cl dan silika gel / [BMIM]ClPelarut yang digunakan adalah aseton dengan suhu reaksi 55 - 60°C. Ester yangdihasilkan merupakan monoester berdasarkan uji KLT. Esterifikasi gliseroldengan katalis [BMIM]Cl tidak menghasilkan ester yang diharapkan. Sedangdengan 0,5 g dan 1 g katalis silika gel / [BMIM]Cl kondisi optimum tercapaipada 20 jam dengan persen hasil produk sebanyak 19,83% dan 29,62%.Karakteristik katalis heterogen menggunakan XRD, XRF, FT-IR. Karakteristikester menggunakan KLT, FT-IR, HPLC dan GC-MS., Glycerol is an alcohol compound having three hydroxyl groups (- OH), whichcan be reacted with carboxylic acid to produce ester. One compound whichincluded into carboxylic acid is p-hydroxy benzoic acid which also is a phenoliccompound. Ionic liquid is known as environmental friendly solvent and catalyst..Since phenolic compounds are known as effective antioxidants, this researchstudied the esterification reaction of glycerol with a phenolic acid, p-hydroxybenzoic acid using ionic liquid as catalyst.The ionic liquid, l-buthyl-3-methyl imidazolium chloride, [BMll\/l]Cl, Was usedin the form of impregnated catalyst in silica gel and as unimpregnated catalyst.The reactants, glycerol and p-hydroxy benzoic acid in mol ratio of 4 1 l, weredisolved in acetone solvent and the esterification reactions were conducted at atemperature around 55 - 60°C up to 24 hours. The reaction products wereanalyzed using thin layer chromatography, HPLC and FT-IR, which showed themonoester product. The reaction with unimpregnated [BMIM]Cl catalyst did notproduce ester product. Where as the rections with [BMIM]Cl impregnated in SiO;produced 19.83% ester product with 0.5 g catalyst and 29.62% ester product with1.0 g catalyst in 20 hours reaction periods.] |
