One-Step Quaternization/Hydroxypropylsulfonation to Improve Paste Stability, Adhesion, and Film Properties of Oxidized Starch

Comprehensive Evaluation of the Physicochemical Attributes, Antioxidant Capacity, and pH-Responsive Behavior of Starch Films Enhanced by Laver Incorporation

Herein, a new starch film incorporating laver was developed to address issues related to inadequate water resistance and suboptimal preservation quality in food packaging. The integration of laver into starch film formulations offers a compelling avenue for creating biodegradable, active, and smart food packaging. Scanning electron microscope (SEM) analysis revealed that the starch film with a laver concentration of 70% exhibited a uniformly flat microstructure, as expected. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of intermolecular interactions and hydrogen bonding between the starch and laver. Viscoelastic tests demonstrated the superior film-forming performance of the starch/laver composite films. Moreover, it was found that the most favorable concentration of incorporated laver was 10%. Specifically, the S7-3 film emerged as a promising candidate for food packaging applications, boasting the highest contact angle (CA) value of 114.98 ± 1.28°, the lowest water solubility (WS) value of 15.38%, and a reduced water vapor transmission rate (WVTR) value of 2.52 g/m2 × h. Additionally, the S3-7 film displayed an extraordinary tensile strength of 32.47 MPa, an elongation at break of 19.04%, and a Young's modulus of 606.83 MPa. Furthermore, the starch/laver composite films exhibited outstanding UV-blocking capabilities, exceptional pH-responsive behavior, and significant antioxidant activity, underscoring their potential for packaging applications with laver integration.

Synthesis of grafted bromoisobutyryl esterified starch using electron transfer atom transfer radical polymerization method with high-performance adhesion and film properties

Nowadays, few investigations on the process parameters of grafted starch synthesized using electron transfer atom transfer radical polymerization (ARGET ATRP) and its applications in warp sizing and paper-making are presented. Therefore, this study aimed to survey the appropriate process parameters of bromoisobutyryl esterified starch-g-poly(acrylic acid) (BBES-g-PAA) synthesized by the ARGET ATRP, and also aimed to provide a new biobased BBES-g-PAA adhesive. The appropriate synthesis process parameters were 1.2, 0.32, and 0.6 in the molar ratios of vitamin C, CuBr2, and pentamethyldivinyltriamine to BBES, respectively, at 40 °C for 5 h. The BBES-g-PAA samples with a grafting ratio range of 4.63-14.14 % exhibited bonding forces of 57.8-64.6 N to wool fibers [55.5 N (BBES) and 53.8 N (ATS)], and their films showed breaking elongations of 3.29-3.80 % [2.74 % (BBES) and 2.49 % (ATS)] and tensile strengths of 29.1-25.4 MPa [30.4 MPa (BBES) and 34.7 MPa (ATS)]. Compared with BBES, significantly increased bonding forces and film elongations, and decreased film strengths for the BBES-g-PAA samples with grafting ratios ≥10.54 % were displayed (p < 0.05). The time (100-42 s) taken for the BBES-g-PAA films was significantly shorter than that of ATS (246 s) and BBES (196 s) films (p < 0.05), corresponding to better desizability.

Modification of biological starch macromolecule with phosphate and dimethylammonium chloride acyloxylate substituents confers good desizability, film properties, paste stability and adhesion

This study revealed the influence of phosphorylation-dimethylammonium chloride acyloxylation (PDACA) on the desizability, film properties, paste stability, and adhesion of biological starch macromolecules. A new starch-based sizing agent, phosphorylated-dimethylammonium chloride acyloxylated starch (PDACAS), was synthesized with degrees of substitution (DS) ranging from 0.033 to 0.065. Compared to control phosphorylated-quaternized starch (PQS, 87.4 %), the desizing efficiency of cotton yarns sized with PDACAS was ~94 %, exceeding the industrial minimum requirement of 90 %. The PDACAS film tensile properties were as follows: elongation at break of 3.31 %-3.78 %, bending endurance of 1131-1537 cycles, and tensile strength of 35.83-28.31 MPa, compared with those of acid-thinned starch (ATS) film (2.74 %, 957 cycles, and 38.12 MPa). The PDACAS had paste stability of ~92 %, compared with 83.3 % for ATS. The bonding forces (an indicator of adhesion to fibers) ranged from 107.1 N to 125.3 N for cotton roving, and 128.3 N to 148.7 N for polyester/cotton roving, which were significantly better than those of ATS (95 N for cotton and 117.9 N for polyester/cotton roving). Overall, PDACA treatment effectively avoided the adverse effect of high DS quaternization on the desizability of PQS and imparted good film properties, paste stability, and adhesion to starch.

Introducing the grafted poly(acrylic acid-co-butyl acrylate) branches onto biological corn starch macromolecule for imparting it with superior sizing properties

The objective of this study was to survey the influence of poly(acrylic acid-co-butyl acrylate) [P(AA-co-BA)] branches on the sizing properties (i.e., paste stability, adhesion, properties of film and sized warps) of biological macromolecule (corn starch) for further promoting the properties of bromoisobutyryl esterified starch (BBES) and developing a new biobased sizing agent [BBES-g-P(AA-co-BA)]. The sizing properties of BBES-g-P(AA-co-BA) were estimated in comparison with acid-hydrolyzed starch (AHS) and BBES. Compared with the two starches, BBES-g-P(AA-co-BA) displayed higher paste stability, bonding forces to both polyester and polyester/cotton roving, film elongation and water solubility, as well as lower film strength. And the increased grafting ratio exhibited positive effects on these properties of BBES-g-P(AA-co-BA). The properties containing increase in strength, loss in extension, abrasion resistance and hairiness of polyester and polyester/cotton blended yarns sized with BBES-g-P(AA-co-BA), were superior to those sized with AHS and BBES, respectively, indicating that the incorporation of P(AA-co-BA) branches onto BBES could further promote the sizing qualities of both yarns. The BBES-g-P(AA-co-BA) with a grafting ratio of 16.51 % was concluded to size both yarns for improvement of yarn quality.

Influence of Sulfododecenylsuccinylation on the Adhesion to Fibers and Film Properties of Corn Starch for Warp Sizing

To improve the film brittleness and adhesion to fibers of dodecenylsuccinated starch (DSS), DSS samples were sulfonated with excess NaHSO3 to prepare a series of sulfododecenylsuccinated starch (SDSS) samples with different degrees of substitution (DS). Their adhesion to fibers, surface tensions, film tensile properties and crystallinities, and moisture regains were studied. The results showed that the SDSS was superior to DSS and acid-thinned starch (ATS) in the adhesion to cotton and polyester fibers and breaking elongation of film but was inferior to them in tensile strength and degree of crystallinity of film, which revealed that sulfododecenylsuccination could further improve the adhesion of ATS to both fibers and reduce its film brittleness compared to starch dodecenylsuccination. With the increase in the DS, the adhesion to both fibers and the film elongation of SDSS gradually increased and then decreased, while its film strength consistently decreased. Considering adhesion and film properties, the SDSS samples with a DS range of 0.024-0.030 were recommended.

Incorporation of poly(3-acrylamidopropyl trimethylammonium chloride-co-acrylic acid) branches for good sizing properties and easy desizing from sized cotton warps

This study aimed to ascertain the influence of poly(3-acrylamidopropyl trimethylammonium chloride-co-acrylic acid) [P(ATC-co-AA)] on the adhesion, film properties, desizability of cornstarch, and reveal a suitable mole percentage of ATC units on the P(ATC-co-AA) for acquiring a new starch-based size [S-g-P(ATC-co-AA)]. A series of S-g-P(ATC-co-AA) samples were synthesized by the graft polymerization of acid-converted cornstarch with ATC and AA monomers. Their adhesion, film properties, and desizability were assessed. The results displayed that the P(ATC-co-AA) branches could significantly improve the adhesion to cotton fibers and diminish the film brittleness of starch. Under similar grafting ratio, the adhesion and desizability of S-g-P(ATC-co-AA) depended on the mole percentage of ATC units. Increasing the percentage favored the adhesion but disfavored the desizability. The percentage displayed a low effect on the film properties. S-g-P(ATC-co-AA) with a mole percentage of 57.7% presented good sizing properties and easy desizing, which had potential application in cotton warp sizing.

Quaternization-butyrylation to improve the viscosity stability, adhesion to fibers, film properties and desizability of starch for warp sizing

The influence of the quaternization and butyrylation on the sizing properties of biological starch macromolecule was evaluated for acquiring a new starch bio-based size [quaternized-butyrylated starch (QBS)]. The sizing properties of granular QBS samples were investigated in comparison with acid-thinned starch (ATS) and quaternized starch (QS). The QBS samples with a DS range of 0.029-0.0779 exhibited bonding strengths of 17.0-18.3 cN/tex to cotton fibers [15.5 cN/tex (ATS, DS = 0) and 16.6 cN/tex (QS, DS = 0.0240)] and 31.0-34.3 cN/tex to polyester fibers [28.0 cN/tex (ATS) and 30.1 cN/tex (QS)], and their films showed breaking elongations of 2.99-3.51% [2.59% (ATS) and 2.81% (QS)] and tensile strengths of 36.5-32.1 MPa [38.1 MPa (ATS) and 37.3 MPa (QS)]. Compared with QS, significantly increased bonding strengths as well as obviously decreased strengths and increased elongations of the films for the QBS samples with the total DS ≥ 0.0635 were exhibited. As increasing the modification levels from 0.029 to 0.0779, QBS presented paste stabilities from 90.4% to 85.7% which met with the requirement in warp sizing, and displayed higher desizing efficiencies (93.2-93.8%) than ATS (91.5%) and QS (90.2%). Based on these results, the amphiphilic quaternization-butyrylation was a good means for starch to acquire good sizing properties.

Starch engineered with Moringa oleifera seeds protein crosslinked Fe3O4: A synthesis and flocculation studies

This study aimed to utilize cationic protein extracted from the Moringa oleifera seed in the fabrication of cationic starch crosslinked with magnetic nanoparticles (MagCS). Important synthesis parameters include starch to cationic protein volume ratio, magnetic nanoparticles mass fraction, reaction and crosslinking time, reaction and crosslinking temperature and crosslinker concentration. At optimum synthesis conditions, MagCS yield a 38.55% amide content, 2.46 degree of substitution, 1.1 mmol/g charge density and 78.6% crosslinking, which are much higher compared to other starch derivatives. A series of characterization analyses such as Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, elemental analysis and vibrating sample magnetometer concluded that MagCS was embedded with amide group, has high crystallinity structure, is thermally stable and shows a promising magnetic characteristic. Based on the synthesis parameters and characterization studies, the synthesis mechanism of MagCS was also postulated. The flocculation performance of MagCS was successfully assessed for the treatment of palm oil mill effluent. At optimum dosage, initial pH and settling time of 1.0 g/L, 9.0 and 15 min, the MagCS flocculant was able to remove 90.48, 83.95 and 58.19% of turbidity, color and chemical oxygen demand, respectively. This study provides an alternative eco-friendly materials in the wastewater treatment application.

Investigating the relationship between structure of itaconylated starch and its sizing properties: Viscosity stability, adhesion and film properties for wool warp sizing

The purpose of this work was to evaluate the effect of itaconation on sizing properties (such as viscosity stability, adhesion and film properties) of biological macromolecule (corn starch) for developing a new bio-based sizing agent [itaconylated starch (IS)]. Granular IS samples were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. The adhesion of IS to wool fibers was investigated by a standard method (FZ/T 15001-2008). And film properties of IS samples were also studied in terms of tensile strength, breaking elongation, bending endurance and degree of crystallinity, etc. Compared with control acid-converted starch (ACS), stronger bonding forces to wool fibers for IS as well as higher breaking elongation and lower tensile strength for IS film were displayed. Increasing the degrees of substitution (DS) of IS samples from 0 to 0.052 was able to achieve gradually enhanced bonding forces, breaking elongation and bending endurance, which implied that increasing the number of itaconate substituents could play a significantly positive role in overcoming the shortcomings (insufficient adhesion and film brittleness) of starch. These experimental results denoted that the granular IS exhibited potential for the use as a new starch-based size in the sizing of wool warp yarns.

Incorporation of poly(sodium allyl sulfonate) branches on corn starch chains for enhancing its sizing properties: Viscosity stability, adhesion, film properties and desizability

The purpose of this work was to examine the influence of poly(sodium allyl sulfonate) (PSAS) branches on sizing properties of biological macromolecule (corn starch) for exploring a new anionic starch graft copolymer size (S-g-PSAS). Successful synthesis of S-g-PSAS samples was confirmed by energy dispersive X-ray spectrometer. Viscosity stability, adhesion, film properties and desizability of the samples were also investigated. Compared with HS, improved adhesion to cotton and viscose fibers, viscosity stability and desizability for S-g-PSAS as well as enhanced breaking elongation and bending endurance for S-g-PSAS film were exhibited. With the rise in grafting ratio, bonding forces to both fibers, viscosity stability and desizability of S-g-PSAS and its film properties such as breaking elongation and bending endurance, were gradually enhanced. These results indicated that S-g-PSAS showed potential for the use as a new starch-based size in the sizing of cotton and viscose warps.

How starch-g-poly(acrylamide) molecular structure effect sizing properties

The effect of starch-g-poly(acrylamide) (S-g-PAM) molecular structure on sizing properties has been investigated. S-g-PAMs were synthesized with the catalysis of horseradish peroxidase (HRP) and Fourier transform infrared (FT-IR) confirmed the acrylamide (AM) units had been successfully grafted on starch chains. Structural parameters, including degree of branching (DB), degree of substitution (DS) and grafting ratio (GR) were characterized by ¹H nuclear magnetic resonance (¹H NMR), and were correlated with sizing properties of apparent viscosity, adhesion to cotton yarns and film mechanical properties. The apparent viscosity of S-g-PAMs has no obvious correlation with DB and DS (or GR), as the amylose content of the native starch might have more influence on the viscosity of grafted starches. DS (or GR) values of grafted starches have a positive relationship with the tensile strength of sized cotton yarns and are negatively related with tensile strength of starch film. These results can provide guidance in the section of starch with improved sizing properties.

Investigation on the Synthesis Process of Bromoisobutyryl Esterified Starch and Its Sizing Properties: Viscosity Stability, Adhesion and Film Properties

To confirm the suitable synthesis process parameters of preparing bromoisobutyryl esterified starch (BBES), the influences of the synthesis process parameters-amount of 2-bromoisobutyryl bromide (BIBB), amount of catalyst (DMAP), reaction temperature and reaction time-upon the degree of substitution (DS) were investigated. Then, to produce a positive effect on the properties of graft copolymers of BBES prepared in the near future, a series of BBES samples were successfully prepared, and their sizing properties, such as apparent viscosity and viscosity stability, adhesion, and film properties, were examined. The BBES granules were characterized by Fourier transform infra-red spectroscopy and scanning electron microscopy. The adhesion was examined by determining the bonding forces of the sized polylactic acid (PLA) and polyester roving. The film properties were investigated in terms of tensile strength, breaking elongation, degree of crystallinity, and cross-section analysis. The results showed that a suitable synthesis process of BBES was: reaction time of 24 h, reaction temperature of 40 °C, and 0.23 in the molar ratio of 4-dimethylaminopyridine to 2-bromoisobutyryl bromide. The bromoisobutyryl esterification played the important roles in the properties of the starch, such as paste stabilities of above 85% for satisfying the requirement in the stability for sizing, improvement of the adhesion to polylactic acid and polyester fibers, and reduction of film brittleness. With rising DS, bonding forces of BBES to the fibers increased and then decreased. BBES (DS = 0.016) had the highest force and breaking elongation of the film. Considering the experimental results, BBES (DS = 0.016) showed potential in the PLA and polyester sizing, and will not lead to a negative influence on the properties of graft copolymers of BBES.

Hydroxypropylsulfonation/Caproylation of Cornstarch to Enhance Its Adhesion to PLA Fibers for PLA Sizing

The impact of hydroxypropylsulfonation/caproylation on the adhesion of cornstarch to polylactic acid (PLA) fibers was investigated for ameliorating the applications such as PLA sizing. The hydroxypropylsulfonated and caproylated cornstarch (HCS) samples with different degrees of substitution (DS) were synthesized by a hydroxypropylsulfonation of acid-converted cornstarch (ACS) with 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt (CHPS-Na) and subsequently a caproylation with caproic anhydride (CA). The HCS granules were characterized by Fourier transform infrared spectroscopic and scanning electron microscopy. The adhesion was evaluated by measuring the bonding forces of the PLA roving impregnated. The mechanical behaviors of the adhesive layers were estimated by determining the properties of the films. The results of adhesion measurement were also analyzed especially through the wetting and spreading of the paste on the fiber surfaces, as well as the failure type, internal stress and mechanical behaviors of the adhesive layers among fibers. Additionally, apparent viscosity and its stability of the pastes were also determined. It was found that hydroxypropylsulfonation/caproylation was not only able to obviously improve the adhesion of ACS to PLA fibers, but also capable of further improving the adhesion of hydroxypropylsulfonated starch (HS) to the fibers. With the rise in the total DS, the adhesion gradually increased. The two substituents improved the wetting and spreading, reduced the internal stress, lowered the probabilities of interfacial failure and cohesive failure, decreased the film brittleness, and increased the van der Waals force at the interfaces. Moreover, the HCS samples with a stability of above 85% could meet the demand on the stability for sizing. Considering the experimental results of the adhesion and the analysis of the results, HCS showed potential in the application of PLA sizing.

Phosphorylation/caproylation of cornstarch to improve its adhesion to PLA and cotton fibers

To investigate the influence of phosphorylation/caproylation on the adhesion of cornstarch to polylactic acid (PLA) and cotton fibers for improving its applications, such as in PLA and cotton sizing, herein, a series of phosphorylated and caproylated cornstarch (PCS) samples with different total degrees of substitution (DS) were synthetized by the phosphorylation of acid-converted cornstarch (ACS) with sodium tripolyphosphate (STP) and subsequent caproylation with caproic anhydride (CA). The PCS granules were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The adhesion was evaluated by determining the bonding forces of the impregnated PLA and cotton roving. The results of the adhesion measurements were also analyzed, especially for the wetting and spreading of the pastes on the fiber surfaces as well as the failure type and internal stress of the adhesive layers among the fibers. In addition, the viscosity stabilities of the pastes were determined. The results showed that phosphorylation/caproylation was capable of obviously improving the adhesion of starch to PLA and cotton fibers. As the total DS increased, the bonding forces gradually increased. The two substituents improved the wetting and spreading, reduced the internal stress, lowered the layer brittleness, and decreased the probabilities of interfacial failure and cohesive failure, thereby favoring the improvement of the adhesion. The PCS samples with stabilities above 85% could meet the stability requirement for sizing. Based on the experimental results of the adhesion and the analysis of the results, it can be concluded that PCS shows potential for applications in PLA and cotton sizing.

PCS samples were prepared for improving the adhesion of starch to PLA and cotton fibers.