Preparation And Properties Of Dialdehyde Starch

Dialdehyde starch is low in toxicity and high in chemical reactivity and has found broad potential applications in various industries. Its production has been commercialized once in some countries with the advent of new oxidant reclamation technology. The properties of solubilization, swelling, stability and rheology of Dialdehyde starch prepared in different conditions have great effect on its applications, as to these research reports are few, so we study the preparation and properties of dialdehyde starch and hope to find the theories to improve the applications of dialdehyde starch.1. The factors that affected the content of dialdehyde in dialdehyde starch included reaction time, reaction temperature, concentrations of sodium periodate, reaction pH, and the ratio of sodium periodate to starch. A four-factor three-level rthogonal experiment was designed with fixed ratio of sodium periodate to starch at 1.1:1. It was found that the optimal conditions were reaction time 3 hours, reaction temperature 35 癈, reaction concentration of sodium periodate 0.6mol/L, reaction pH 3.5.2. Studied the solution properties of different dialdehyde content's dialdehyde starch prepared at pH3.5, 7, 9 in different solvents, and also studied the swelling properties of different dialdehyde content dialdehyde starch prepared at pH3.5, 7, 9 in different temperature. The experimental results shown that the serriation of solubility and swelling of dialdehyde starch in different solvent was saturated zinc chloride solution > DMSO > 8mol/L urea solution > ethanol > pure water; and that the seriation of solubility of dialdehyde starch prepared at different pH was pH9 > pH7 > pH3.5; and that dialdehyde starch containing low dialdehyde was more soluble and swelling than that containing high dialdehyde.3. Studied the stability properties of different dialdehyde content's dialdehyde starch prepared at pH3.5, 7 and 9. The experimental results shown that dialdehyde starch was more stable at low pH than that at high pH; and that dialdehyde starch prepared at high pH was more stable than that prepared at low pH; and that the stabilityof dialdehyde starch in DMSO was highest; and that dialdehyde starch containing low dialdehyde had better salt tolerance stability than that containing high dialdehyde.4. The rheological study of dialdehyde starch shown that dialdehyde starch prepared at pH3.5 is lower than that prepared at pH7. It also indicated that the viscosity of dialdehyde starch increased a little bit with the increasing of shear rate.