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

Development of a Novel Energy Saving and Environmentally Friendly Starch via a Graft Copolymerization Strategy for Efficient Warp Sizing and Easy Removal

Warp sizing is a key process in textile production. However, before the yarn/fabric finishing, such as dyeing, the paste adhering to the warp must be eliminated to ensure optimal dyeing properties and the flexibility of the fabric. Therefore, the sizing will often consume a lot of energy and produce a lot of industrial wastewater, which will cause serious harm to the environment. In this study, we have developed an energy saving and environmentally friendly starch-based slurry by modifying natural starch with acrylamide. The paste has excellent viscosity stability and fiber adhesion, and exhibits excellent performance during warp sizing. In addition, the slurry has good water solubility at 60-70 °C, so it is easy to desize at low temperatures. Because of this, the sizing of the warp can be deslimed directly from the yarn during subsequent washing processes. This work can not only reduce some costs for the textile industry, but also achieve the purpose of energy conservation and emission reduction.

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.

Scalable Underwater Adhesives with High-Strength, Long-Term, and Harsh-Environment Adhesion Enabled by Heterocyclic Chemistry

Developing scalable and high-performance underwater adhesives is important in various biomedical and industrial applications. However, despite massive efforts, the realization of such adhesives remains a challenging task, as mainly imposed by the difficulty in balancing the interfacial and bulk properties via an efficient way. Here, we report a facile yet effective strategy to construct a novel underwater adhesive with multiple advantaged performances by virtue of heterocyclic chemistry. This adhesive is designed with the cooperation of a heterocycle-based versatile adhesive functionality and an eco-friendly hydrophilic matrix with cross-linkable sites, which allows water absorption to destroy hydration layer, diverse molecular interactions to enhance interfacial adhesion, and abundant covalent crosslinks to strengthen bulk cohesion. Such a rational design endows the adhesive with strong underwater adhesion (up to 1.16 MPa for wood and 0.36 MPa for poly(tetrafluoroethylene) (PTFE)), long-term durability (maintaining pristine strength even after 4 months), and harsh-environment stability (salt, acidic/alkaline, low/high-temperature solutions). This strategy is also generic to derive more adhesive formulas, which offers a new direction for designing the next-generation underwater adhesives with high performance and scalability for practical applications.

Achieving strong, stable, and durable underwater adhesives based on a simple and generic amino-acid-resembling design

Developing underwater adhesives is important in many applications. Despite extensive progress, achieving strong, stable, and durable underwater adhesion via a simple and effective way is still challenging, mainly due to the conflict between the interfacial and bulk properties. Here, we report a unique bio-inspired strategy to facilely construct superior underwater adhesives with desirable interfacial and bulk properties. For adhesive design, a hydrophilic backbone is utilized to quickly absorb water for effective dehydration, and a novel amino acid-resembling functional block is developed to provide versatile molecular interactions for high interfacial adhesion. Moreover, the conjunction of these two components enables the generation of abundant covalent crosslinks for robust bulk cohesion. Such a rational design allows the adhesive to present a boosted underwater adhesion (3.92 MPa to glass), remarkable durability (maintaining high strength after one month), and good stability in various harsh environments (pH, salt, high temperature, and organic solvents). This strategy is generic, allowing the derivation of more similar adhesive designs easily and triggering new thinking for designing bio-inspired adhesives and beyond.

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.

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.

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.