Polymers based on chemically modified starch

In our research, we are developing materials based on chemical modified wheat starch ant its derivatives. The starch is esterified with various acids or acid anhydrides, e.g. acetic or propionic acid. Main goal of this work is to determine the degree of substitution, which has significant relevance in study of modified saccharides. it was done using three different techniques - acid-base titration, elemental analysis and nuclear magnetic resonance spectroscopy