Oxysucrose polyaldehyde: A new hydrophilic crosslinking reagent for anti-crease finishing of cotton fabrics

Anti-Wrinkle and Dyeing Properties of Silk Fabric Finished with 2,4,6-Trichloropyrimidine

Silk, a natural protein fiber, is widely used in the textile industry and biomedical materials for its excellent properties. However, its application in some fields is seriously restricted due to its poor anti-wrinkle behavior. In this study, 2,4,6-trichloropyrimidine (TLP) was used in the production of anti-wrinkle silk fabrics. The optimum finishing conditions were as follows: 3-g/L 2,4,6-trichloropyrimidine, 6-g/L NaHCO3, 8-g/L Na2SO4, finishing temperature of 65 °C, and finishing time of 40 min. The crease recovery angle of the finished fabric is 16–20% higher than the unfinished fabric, and the finishing process has a small effect on the whiteness of silk while achieving some degree of washing resistance. The morphology and chemical structures of the finished silk fabric were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The K/S value of the finished silk fabric dyed with reactive dyes increased compared with the silk fabric only dyed, indicating that the dyeability of the finished fabric was improved. This technology provides a new method for fabricating silk color crease-resistant fabrics.

Structural Analysis of Oxidized Sucrose and Its Application as a Crease-Resistant Crosslinking Agent

Oxidized sucrose is a non-formaldehyde crosslinking agent with many applications in polymer crosslinking and modification, such as in the preparation of starch films and protein films. However, research on the structure of oxidized sucrose is lacking. In this paper, oxidized sucrose was synthesized through selective oxidation of sodium periodate. By LC-MS, FTIR, TGA, NMR, and HRMS analyses, it was shown that oxidized sucrose existed in the form of a hydrate, and the tetraaldehyde oxidized sucrose could isomerize into the form of two six-membered hemiacetal rings. The structure of oxidized sucrose was also verified by theoretical calculations. Furthermore, the diffusional properties of oxidized sucrose were investigated by the rolling-film method. Finally, it was found that oxidized sucrose used as a crosslinking agent could effectively improve the wrinkle recovery performance of cotton fabrics.

Bridging-induced densification strategy based on biomass-derived aldehyde tanning integrated with terminal Al(III) crosslinking towards high-performance chrome-free leather production

Chrome-free leather manufacturing has been acknowledged as a desirable option to eliminate potential environmental and human health risks of conventional chrome tanning. This work applied a sequential bridging-induced densification strategy to produce high-performance chrome-free leather with high crosslinking density derived from the biomass-derived aldehyde (BAT) crosslinking (BAT tanning of leather), followed by terminal Al(III) crosslinking (TAC). The TAC conditions for BAT tanned leather were optimized and the results suggested that the optimized conditions were as follows: the fixation pH was 4.2, the pre-penetration time was 180 min, the fixation temperature was 40 °C, and the dosage of the aluminum tanning agent (ATA) was 0.5% (based on Al₂O₃). Under the optimized conditions, the resultant BAT-TAC crust leather exhibited favorable overall performances compared with BAT crust leather in terms of higher hydrothermal stability, mechanical strengths, more pleasant uniform color, and comparable smooth grain surface. The obtained high-performance chrome-free leather is scalable, providing an avenue for designing and rationalizing other engineering technology towards high-performance eco-leather production.

Study on the cross-linking process of carboxylated polyaldehyde sucrose as an anti-wrinkle finishing agent for cotton fabric

Sucrose was oxidized in a two-step oxidation reaction catalyzed by 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-laccase and sodium periodate (NaIO4). To generate carboxylated polyaldehyde sucrose (openSu) containing multiple aldehyde and carboxyl groups. The amount of TEMPO and laccase used, as well as the temperature and reaction time were optimized for the oxidation reaction. The successful combination of aldehyde and carboxyl groups of openSu with cellulose was achieved by changing the composition, ratio of the catalyst and the curing conditions. Thereafter, we analyzed the structural characteristics of openSu as well as the aldehyde and carboxyl group content using nuclear magnetic resonance carbon spectroscopy (13C NMR). We found that the optimal finishing conditions were a mixture of magnesium chloride and sodium hypophosphite at a mass concentration ratio of 16 g/L:4 g/L, and curing at 150 °C for 3 min followed by curing at 180 °C for 2 min. There was significant improvement in the anti-wrinkle performance of the openSu-finished fabric, with a wrinkle recovery angle of 258°, whiteness index of 72.1, and a tensile strength rate of more than 65%. We also studied the covalent crosslinking mechanism between openSu and the cotton fabrics.

Locating the Reaction Site of 1,2,3,4-Butanetetracarboxylic Acid Carboxyl and Cellulose Hydroxyl in the Esterification Cross-Linking

The modification of cellulose with polycarboxylic acid is an important technology to functionalize the substrate. 1,2,3,4-Butanetetracarboxylic acid (BTCA) can significantly improve the anti-wrinkle performance of treated cotton fabrics by cross-linking with cellulose. However, the reaction site of BTCA carboxyl and the cellulose hydroxyl has not yet been clarified, which hinders the in-depth understanding about the reaction mechanism and the development of new cross-linking reagents. This study combines Fourier transform infrared and two-dimensional correlation spectroscopy to try to make it clear. Results confirmed that BTCA anhydride is an active intermediate (corresponding to the generally accepted theory) to esterify with cellulose hydroxyl, especially the O(6)-H(6) and O(2)-H(2). Cellobiose was taken as a model of cellulose to react with BTCA at variable temperatures, proving the above conclusion. In addition, the C14- or C11-containing carboxyl of BTCA showed a higher reactivity. Based on calculating reaction kinetics and thermodynamics with Gaussian 09W software, the most likely reaction route between BTCA and cellulose was as follows: BTCA → BTCA C5C14 anhydride → C14O15 ester → C14O15 ester C31C34 anhydride → C14O15C33O ester.

High temperature ATR-FTIR characterization of the interaction of polycarboxylic acids and organotrialkoxysilanes with cellulosic material

To convey novel properties to textile surface cotton-based fabrics were impregnated with solutions containing various chemical agents, such as butane-1,2,3,4-tetracarboxylic acid or hydrolyzed organotrialkoxysilanes (3-amino)propyltriethoxysilane), (3-glycidylpropyl)-trimethoxysilane, (3-triethoxysilylpropyl)succinic acid anhydride, octyltriethoxysilane, and Dynasylan F8815 (fluoroalkylfunctional water-borne oligosiloxane). The as-prepared cotton specimens were dried and cured at elevated temperatures. As the curing process can be performed at different temperatures, the impregnated and dried cotton samples were studied by means of time-dependent ATR-FTIR spectroscopy in an attempt to get a closer insight into the process mechanism. The results make evident that the butane-1,2,3,4-tetracarboxylic acid and (3-triethoxysilylpropyl)succinic acid anhydride reacts with the hydroxyl groups of the cellulose via a five-membered cyclic anhydride intermediate which is confirmed by vibration bands appearing at 1782 cm^-1 (symmetric stretching vibration of the anhydride carbonyl group) and at 1861 cm^-1 (antisymmetric stretching vibration of the anhydride carbonyl group).