Modification of Starch via the Biginelli Multicomponent Reaction.

An efficient and straightforward modification of starch using renewable and commercially available aromatic aldehydes (benzaldehyde, vanillin, and p-anisaldehyde) and urea via the Biginelli multicomponent reaction is reported in this work. First, starch acetoacetate (SAA) with a degree of substitution ranging from 1.4 to 2.5, depending on the reaction time or the molar ratio of reactants, is prepared. SAA is then modified with different aromatic aldehydes and urea via the Biginelli reaction. The modified products are characterized by ATR-IR, NMR, and gel permeation chromatography (GPC). The processability of the products is also investigated using a hot press instrument, revealing that glycerol is a suitable and renewable plasticizer for the Biginelli products.