Chemical Modification of Starch via Etherification with Methyl Methacrylate

Bayazeed, A.; Farag, S.; Shaarawy, S.; Hebeish, A.

doi:10.1002/(sici)1521-379x(199803)50:2/3<89::aid-star89>3.0.co;2-b

Cited by 17 publications

(11 citation statements)

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“…The immobility of the hydroxyl groups made this acetylation reaction essentially dependent on the availability of acetic anhydride molecules in the proximity of the starch molecules (Bayazeed et al 1998). When the AA/S ratio increased further to 5, DS did not increase.…”

Section: Effects Of Reaction Times and The Ratio Of Acetic Anhydride mentioning

confidence: 99%

Synthesis and Characterization of Starch Acetates with High Substitution

Miladinov²,

2004

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Cereal Chem. 81(6):735-740Acetylation of high-amylose (70%) maize starch to high degree of substitution (DS) was studied by reacting starch with acetic anhydride using 50% aqueous NaOH as the catalyst. DS increased with increasing reaction times and increasing ratios of acetic anhydride to starch. Reaction efficiency (RE) increased with longer reaction times and decreased with increases in the ratios of acetic anhydride to starch for extended reaction times. Increasing the amount of NaOH increased both DS and RE. A series of starch acetates with DS values of 0.57-2.23 were prepared and their crystalline structures, chemical structures, thermal stability, and morphological properties were investigated. After acetylation, and as DS increased from 0.57 to 2.23, the crystalline structures of starch steadily disappeared. The carbonyl group's peak at 1,740 cm -1 appeared in the FTIR spectra. The intensity of this peak increased with a decrease in the peak intensity of the hydroxyl groups at 3,000-3,600 cm -1 , indicating that the hydroxyl groups on starch were replaced by the acetyl groups. Thermal stability of starch acetates increased. The smooth surface of the starch granules became rough with acetylation. Further acetylation led to the loss of the starch granules and the formation of beehive-and fibrouslike structures.

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Section: Effects Of Reaction Times and The Ratio Of Acetic Anhydride mentioning

confidence: 99%

Synthesis and Characterization of Starch Acetates with High Substitution

Miladinov²,

2004

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“…Maize starch dominates with as hare of 82 %o ft he worldwide production. Esterification, [6] etherification, [7] grafting, [8] and crosslinking [9] are some of the most frequently employed methods for the chemical functionalization of starch. [3] The botanical origin of starch influences the ratio of amylosea nd amylopectin, which is distinctive for the properties of starch.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Transesterification of Starch with Plant Oils: A Sustainable and Efficient Route to Fatty Acid Starch Esters

Söyler

Meier

2016

ChemSusChem

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The transesterification of maize starch with olive oil or high oleic sunflower oil was studied under homogeneous conditions in the presence of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as catalyst. Most importantly, this method used two renewable resources directly, without any pretreatment or derivatization, for the synthesis of polymeric materials with desirable properties. Moreover, the solvent, oils, and catalyst could be recovered through facile work-up and reused for further modifications. The obtained fatty acid starch esters (FASEs) were highly soluble in common organic solvents and were thoroughly characterized. Degrees of substitution (DS) were calculated using P NMR spectroscopy, and DS values of approximately 1.3 were obtained. Differential scanning calorimetry analysis revealed thermal transitions of the modified starches at approximately 80-90 °C. Films were produced from these FASEs, and their hydrophobic surfaces were characterized using contact-angle measurements. Furthermore, mechanical properties were examined using tensile strength measurements and showed approximately 40 and 80 % elongation at break for modified maize starch and modified amylose from maize, respectively.

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“…These authors explained their results based on the hypothesis that high acetic anhydride concentrations resulted in a high molecular collision rate and also led to greater availability of acetic anhydride molecules in the vicinity of starch. The immobility of the hydroxyl groups made the acetylation reaction system essentially dependent on the availability of acetic anhydride molecules in the proximity of the starch molecules (Bayazeed, Farag, Shaarawy, & Hebeish, 1998). In a similar reaction system, Han et al (2012) assayed the effect of lower acetic anhydride/starch w/w ratios (i.e.…”

Section: Study Of the Effect Of Reaction Parameters On Dsmentioning

confidence: 99%