Effect of reaction temperature and time on properties of esterified starch prepared by dry method

Maleic anhydride esterified starch was prepared by dry method,and then the properties of esterification starch under different reaction temperature and time were studied.Fourier transform infrared spectrum(FT-IR) was used to prove that maleic anhydride was reacted with starch successfully.Using chemical titration method,X-ray diffraction(XRD),differential scanning calorimetry(DSC) and thermo gravimetric analysis(TGA) to analysis the substitution degree,crystal structure,gelatinization temperature and thermal stability of esterification starch.The results showed that substitution degree was increased with the increase of the reaction temperature and time gradually.Esterification reaction damage starch crystal structure in a certain extent,the crystallinity decreased gradually along with the increase of reaction temperature and reaction time.Gelatinization temperature and thermal stability were closely related with the crystallinity of esterified starch.Gelatinization temperature and the thermal stability were decreased along with increasing crystallinity gradually.