Abstract:The preparation method and the product properties of cross-linked esterified corn starch were studied by using terephthaloyl chloride as the crosslinking agent. Single factor experiment was used to optimize the preparation of terephthaloyl chloride cross-linked esterified starch, and the fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and brabender viscometer were used for the characterization of the prepared products. The physicochemical properties of terephthaloyl chloride cross-linked esterified starch such as light transmittance and salt resistance were measured, providing a theoretical basis of the study on terephthaloyl chloride cross-linked esterified starch. The results of infrared absorption spectrum (IR) showed that the characteristic absorption peak appeared at around 1570 cm-1 was attributed to benzene ring, which indicated that the benzene ring was successfully introduced on the cross-linked starch. XRD spectrum showed that crosslinked starch and original starch belonged to A-type structure, and the crystallinity of crosslinked starch decreased slightly, which indicated that crosslinking reaction had an effect on the overall structure of the starch granules. In addition, the crosslinking reaction did not cause serious damage to the crystalline and subcrystalline regions. The optimum preparation conditions were as follows: amount of terephthaloyl chloride 5% of dry starch, amount of sodium hydroxide 4% of dry starch, reaction temperature 45 ℃, reaction time 7 h.
