Synthesis and Characterization of Corn Starch Phthalate by a Semidry Method

Abstract

Starch phthalate (SP) with plasticity and hydrophobicity can have a better adhesion to aromatic polyesters compared with other esterified starch. Hence, modification of corn starch with phthalic anhydride (PA) is carried out by using a semidry method, and the product SP with varied degrees of substitution (DS) is characterized by group titration, Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), scanning electron microscope (SEM), rapid viscosity analysis, thermogravimetric analysis, film transmittance test, and water contact angle measurement. The results show that a small amount of N,N‐dimethylformamide (DMF) as the solvent for dissolving PA can help to greatly increase the DS of the SP samples. The phthalate group is successfully introduced into starch structure by the semidry method under the recommended reaction conditions of 150 °C for 2 h. Compared with native corn starch, SP samples have lower values of crystallinity, paste viscosity, retrogradation, and thermal degradation temperature, and higher values of carbon residue in thermal decomposition, of transparency and hydrophobicity for the films. Due to these good characteristics, the modified starch, SP, may have great potential applied in starch film, adhesives, textile sizes, and so on.

Design and Development of Modified Starch from Indonesian Cassava (Manihot esculenta Crantz) for Enteric Film Coating Polymer Applications

“…The value of 0.0018 indicates the presence of 1 phthalate molecule for every 1000 anhydroglucose units. Phthalate substitution is expected to occur in the starch reactive group, namely at C positions 2, 3 and 6, with the greatest possible substitution at the C-2 position because of the greatest reactivity [17] .…”

Modeling and Optimization of the Shear Strength of Cassava Starch-Based Adhesives Using Artificial Intelligence Methods

“…The characteristic peak at about 3400 cm −1 was -O-H stretching vibration of amylose and amylopectin [44]. In this band, the location of the absorption peak changed from 3391 to 3432 cm −1 , which may be attributed to the hydrogen bonds dissociation [45]. Furthermore, the absorption peak intensity of cassava starch was higher than that of the CSA-OP.…”

“…9a can be separated into three stages at 25∼150°C, 150∼500°C, and 500∼800°C, respectively. The mass loss rate below about 150°C was mainly caused by the evaporation of free water [45][46][47]49]. The large mass loss rate of the main decomposition stage (150∼500°C) was attributed to the starch thermal decomposition.…”

“…The characteristic peak at 2927 cm −1 was caused by the antisymmetric vibration of -CH 2 groups [47,48]. The characteristic peak at 1650 cm −1 was due to C−O stretching vibration and the water molecules absorbed in the amorphous region [44][45]47,49]. Moreover, the characteristic peak at 1160 cm −1 was attributed to glucosidic C-O-C vibration, 1080 cm −1 was corresponded to D-glucopyranose and hydroxyl-linked C-O stretching and vibration [50].…”

Synthesis and characterization of native and modified bitter yam starch grafted with acrylonitrile

“…Among all the chemical modification procedures, esterification can simply and effectively enhance the flexibility and hydrophobicity of starch [16] . Although aliphatic anhydrides such as octene succinic anhydride, octene succinic anhydride, and acetic anhydride have been used to alter starch [17][18][19][20] , aromatic anhydrides such as phthalic anhydride have received less attention in starch esterification than aliphatic anhydrides [21] . When an aromatic group of esters is added to starch, however, it can improve flexibility, hydrophobicity, and diminish hydrogen bonds between starch molecules.…”