Studies On The Preparation Of Dialdehyde Starch From Cassava Starch By Electrochemistry Method

The dialdehyde starch has been extensively applied in paper making and spinning industry. There are two methods for preparation of dialdehyde starch. In one-step system, the oxidation of starch and the conversion from iodic acid to periodic acid were taken place in the same container. For the two-step system, the oxidation of starch and the conversion from iodic acid to periodic acid were reacted in different containers. There are many advantages in preparation of dialdehyde starch by electrochemistry method, e.g. mild reaction condition; easy -control operation; no wastewater, residue and exhausting gas etc. Based on the characteristics in preparation of dialdehyde starch by positive electrolyte chemical oxidation, we developed a method to measure the content of I 0₃^- and I O₄^- in electrolyte. The preparation was in an electrolysis reactor with cassava starch and iodic acid used as raw materials. The main factors affecting dialdehyde starch preparation have been investigated for both one-step or two-step methods.The contents of NaIO₃ and NaIO₄ in anodic electrolyte have been measured by the continuous titration method. The pH value of test solution should be controlled within 1.38 to 1.81. The appropriate masking reagents of 0.50 - 0.54 mL sodium molybdate and 0.30 g demasking reagent of oxalic acid have been applied for sodium thiosulfate titration determination of NaIO₃ and NaIO₄ with good recovery.