A more efficient synthesis and properties of saturated and unsaturated starch esters. (15th September 2022)

• Record Type: Journal Article
• Authors: Boetje, Laura; Lan, Xiaohong; Silvianti, Fitrilia; van Dijken, Jur; Polhuis, Michael; Loos, Katja
• Is Part Of: Carbohydrate polymers. Volume 292(2022)
• Publication Date: 2022-09-15
• Subjects: Methyl oleate (PubChem CID: 5364509) -- Methyl linoleate (PubChem CID: 5284421) -- Methyl stearate (PubChem CID: 8201) -- Methyl trans-2-octenoate (PubChem CID: 5364532) -- Methyl octanoate (PubChem CID: 8091) -- Methyl 10-undcenoate (PubChem CID: 8138) -- Methyl undecanoate (PubChem CID: 15607); TBD 1, 5, 7-triazabicyclo[4.4.0]-dec-5-ene -- DMSO dimethyl sulfoxide -- DSC differential scanning calorimetry -- TGA thermogravimetric analysis -- AGU anhydrous glucose unit -- BHT 3, 5-di-tert-4-butylhydroxytoluene -- CDCl3 chloroform‑d -- DMSO‑d6 dimethyl sulfoxide-d6 -- XRD x-ray diffraction -- NS native starch -- SOc starch octanoate -- STOc starch trans-2-octenoate -- SU starch undecanoate -- S10U starch 10-undecenoate -- SS starch stearate -- SO starch oleate -- SL starch linoleate -- FWHM full width at half maximum; Fatty acid starch ester -- Unsaturated fatty acid -- Transesterification -- Thermal properties -- Side-chain crystallinity -- Hydrophobicity; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2022.119649
• Languages: English
• ISSNs: 0144-8617

Abstract

Abstract: This work presents a series of starch esters synthesized via 1, 5, 7-triazabicyclo[4.4.0]-dec-5-ene (TBD) catalyzed transesterifications in dimethyl sulfoxide (DMSO). The reaction was performed with saturated and unsaturated fatty acids (8, 11, and 18 carbon atoms). The degree of substitution (DS) was raised by purging the reaction flask with nitrogen instead of simply performing the reaction under a nitrogen atmosphere. The increase of DS was most obvious for long-chain fatty acids, as an almost complete DS was observed for starch stearate (2.8) and starch oleate (2.7). The products were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction. Starch esters from unsaturated fatty acids have a lower Tg than their saturated analogues. Moreover, contact angle and moisture uptake measurements showed increased hydrophobicity for all starch esters in comparison to pristine starch. Our results show a more efficient method for synthesizing a biobased material that steers into the direction of a material that could replace conventional plastics. Graphical abstract: Unlabelled Image