Submitted to: Carbohydrate Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 14, 2005
Publication Date: May 30, 2006
Citation: Biswas, A., Shogren, R.L., Kim, S., Willett, J.L. 2006. Rapid preparation of starch maleate half-esters. Carbohydrate Polymers. 64(3):484-487. Interpretive Summary: Among the industrial materials, starch is one of the cheapest and most cost-effective. It is currently used industrially as coatings and sizing in paper, textiles and carpets, as binders and adhesives, as absorbants, and as encapsulants. Starch is often esterified to improve its end-use properties. A novel method for the rapid preparation of starch esters is described herein, by the use of microwave. In this work, we developed a rapid method for the preparation of starch esters by increasing reaction efficiency and decreasing the reaction time. Starch ester manufacturers may potentially benefit from this work.
Technical Abstract: A novel method for the rapid preparation of starch esters is described herein, by the use of microwave. A microwave assisted 5 minute method to prepare starch maleates with DS up to 0.25 was developed when starch in DMSO reacted with 0.5 equivalent maleic anhydride in the presence of 0.5 equivalent of pyridine with a reaction efficiency of 50%. For a given amount maleic anhydride higher amount pyridine gave higher DS. The reactivities of maleic and succinic anhydrides were compared. Succinic anhydride/starch gave DS of 0.3 as compared to only 0.1 with maleic anhydride/starch. The effects of varying reaction time, microwave power, anhydride and pyridine amount on the reaction yield and composition were studied. Proton NMR and IR were used to determine the degree of substitution.