Submitted to: International Chemical Congress of Pacific Basin Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2005
Publication Date: 12/15/2005
Citation: Shogren, R.L., Biswas, A. 2005. Preparation of starch esters using efficient processes [abstract]. International Chemical Congress of Pacific Basin Meeting. p.117. Interpretive Summary:
Technical Abstract: Starch acetates were prepared using microwave heating and/or novel catalysts in effort to reduce energy inputs, byproducts and waste water. Starch acetates of degree of substitution (DS) 0.3-1.5 were prepared with nearly 100% reaction efficiency by microwave heating of dry starch, acetic anhydride and acetic acid at 150-160 deg C for 3-8 min. Somewhat higher temperatures and/or longer times were required to achieve similar reactions using conventional heating. Starch acetates up to DS 2.8 were prepared under milder conditions (40-80 deg C) using starch gelatinized in acetic acid, acetic anhydride and small amounts (~1 mole%) of scandium trifluoromethanesulfonate (ScOTf) catalyst. Using small amounts of iodine as catalyst, starch acetates of DS 1.6 were made from granular starches and acetic anhydride with high efficiency after heating at 100 deg C for 10 min. These catalysts, although relatively expensive, are soluble in water or alcohol and thus may be recovered and reused after reaction.