Kinetics of the Benzylation of Potato Starch

Free, Hugh; Joosten, G.E.H.; Roelfsema, W. A.; Stamhuis, Eize

doi:10.1002/star.19850370105

Cited by 5 publications

(3 citation statements)

References 4 publications

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“…When NaOH content was above 8 %, stirring of the aqueous starch dispersion became difficult because of the viscosity increase. Free and coworkers reported that alkali consumption by starch and benzyl chloride was the most important factor in the benzylation of potato starch [13].…”

Section: Effect Of Alkali On Reaction Yieldmentioning

confidence: 99%

Preparation and Properties of Benzyl Corn Starches

Cho¹,

Lim

1998

Starch/Stärke

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Benzyl corn starches (DS 0.02-0.16) were prepared by reacting starch with benzyl chloride in an alkaline aqueous medium at 65°C, and the pasting properties of the starches were investigated. Reaction yield with 20 % benzyl chloride (based on starch weight) for 12 h was increased from 26.7 % to 60.5 % as the NaOH addition increased from 3 % to 8 % (based on starch weight), and became relatively constant thereafter. With 20 % benzyl chloride and 8 % NaOH, degree of substitution (DS) reached 0.16. Light transmittance and viscosity of starch paste were decreased as DS increased. Low viscosity and opaqueness of the paste indicated that the benzyl groups increased hydrophobicity, and reduced solubility of the starch. Onset temperature (T o ) for starch melting measured by a Differential Scanning Calorimeter thermogram was decreased as DS increased up to 0.1. But above DS 0.1, T o increased. Melting enthalpy was also decreased as DS increase because of the incomplete gelatinization. Solubility in aqueous methanol (80 %) increased near 2 % as DS reached 0.16. Maximum wavelength and absorbance of the iodine complexes of benzyl starch were decreased with benzylation.* Journal paper No. CAFST 97006

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Section: Effect Of Alkali On Reaction Yieldmentioning

confidence: 99%

Preparation and Properties of Benzyl Corn Starches

Cho¹,

Lim

1998

Starch/Stärke

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“…Starch ethers show a greater stability at higher pH. In addition, benzylation gives the modified starch a hydrophobic character that enables solubility in organic solvents and also endowed compatibility with synthetic petroleum plastics 2, 3. Because of the high hydrophobicity, the substituted starch shows low water solubility and almost no pasting viscosity 4.…”

Section: Introductionmentioning

confidence: 99%

“…The substitution reactions are often carried out in a water alkali medium containing benzyl chloride under heterogeneous conditions for lower temperatures up to 60°C 1, 3, 7, 14 and only to low degrees of substitution in the range from 0.1 to 1.0, where the requirements of crystallinity, ductility, stability, solution properties, and compatibility with other polymers are usually sufficient 10.…”

Section: Introductionmentioning

confidence: 99%

Spectral analysis and physical properties of benzylated starch

et al. 2012

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A-and B-wheat starch (in native or acetylated form) and potato starch (slightly acetylated) were subjected to benzylation with benzylchloride in various reaction conditions and at various reaction times (40-1008C, 1-90 h). Modified and original starches were characterized by elemental analysis and spectroscopic methods (FT-IR and 1H NMR). The semicrystalline or amorphous character was indicated by X-ray powder (XRD) patterns. Rheological properties of benzyl starch of DS $ 1 were measured by small amplitude oscillation shear rheology (SAOS) using the rheometer Haake Rheostress RS 80. The results indicated predominantly elastic behavior because the storage modulus was higher than the loss modulus over the whole frequency range; it corresponded to a true gel. The storage and loss moduli increased with increasing frequency while the tangent of phase did not change and was approximately d ¼ 408.

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Development of Hydrophobic Starch

2004

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The aim of this work was a systematic investigation of the preparation conditions for stable aqueous dispersions of hydrophobic starch. Samples of benzylated starch were therefore synthesised and then converted into hydrophobic dispersions by fragmentation. In the study, the type of starch and process parameters such as the degree of hydrophobic substitution and fragmentation method were varied. It was shown that the type of derivatisation process (i.e. heterogeneous in a slurry or homogeneous in an autoclave) had a crucial influence on the dispersion properties. Dilution from homogeneous solution and steam‐jet cooking were explored as fragmentation methods for the starch derivatives. The resulting dispersions were comprehensively characterised in relation to the molecular properties of the soluble fraction and sediment. Significant differences in dispersion properties were caused by the type of starch used (i.e. potato or maize) and the derivatisation process, for a similar degree of benzylation.

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Kinetics of the Benzylation of Potato Starch

Cited by 5 publications

References 4 publications

Preparation and Properties of Benzyl Corn Starches

Preparation and Properties of Benzyl Corn Starches

Spectral analysis and physical properties of benzylated starch

Development of Hydrophobic Starch

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