Synthesis and Characterization of Starch Vernolates in Organic Solvents

In this study the synthesis of epoxy fatty acid esters of starch (starch vernolates) by the reaction of cassava starch with vernonia oil methyl ester (epoxy ester) using basic catalyst K 2 CO 3 and organic solvent, DMSO as a reaction medium is presented. Under current reaction conditions, a high degree of substitution of 1.24 was achieved, at a reaction temperature of 110°C and 12 hours of reaction time. The new starch vernolates were characterized by Scanning electron microscopy (SEM) and X-ray diffraction (XRD) indicated that the new product is an amorphous material with a continuous and shapeless morphology. The melting point measured by differential scanning calorimetry (DSC) was 118°C. The new synthetic method makes the synthesis of starch vernolates less time consuming and more inexpensive. The differences in melting point and degree of substitution with previously synthesized starch vernolates using enzymatic and chemical catalysis suggest a difference in reaction selectivity via this new reaction path.