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.

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.

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.

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.

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.