Effects of Emulsifiers on Engineering and Microstructural Properties of HPMC/Shellac Composite Films

Abstract

Hydroxypropyl methylcellulose/Shellac-based Composite (HPMC/Sh composite) is produced from oil/water emulsion. The emulsifiers are necessarily used to stabilize and enhance the dispersion of this emulsion. This study conducted the experiments to evaluate effects of saturated fatty acids of lauric acid (LA), stearic acid (SA) and unsaturated fatty acid of oleic acid (OA) to the sensory, mechanical properties and microstructure of the HPMC/Sh emulsion. In which, the saturated fatty acids were used in mixtures with the ratios of shellac : emulsifier at 20 : 1, 10 : 1, and 5 : 1. On the other hand, the unsaturated fatty acid was used in mixtures with the ratio of shellac : emulsifier at 1 : 5, 1 : 10, and 1 : 20. The emulsifiers increased the dispersion and effective interaction of the polymers causing the emulsion formation become more stable and finer particle size. In addition, the films had smooth surfaces without unfractured, flexible and elastic.