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As the most common synthetic fibre, polyester has consistently been in high demand and usage, but its recycling has always been a problem for the textile industry. The decolorisation of dyed polyester is the key to expanding its recycling use, and there is no rapid, effective and simple decolorisation method. In this study, ozone was used to decolorise dispersed dyes developed for polyester. Ozone was effective in decolorising CI Disperse Orange 30 and CI Disperse Blue 60, and the process was extended to the decolorisation of dyed polyester fabric. Based on single factor analysis, the optimum decolorisation technological conditions were: an ozone feed rate of 130 mg L−1 min−1, treatment time of 2 hours, wet pick‐up of 100% and pH value of 3, with which the decolorisation rate and colour difference values could exceed 45% and 6%, respectively. The changes in dye structure during the process of ozone decolorisation were analysed using scanning electron microscopy, X‐ray diffraction and Fourier Transform–infrared spectroscopy, and the mechanism of ozone decolorisation was also investigated. The results showed that the crystallinity decreased from 41.18% to 36.30% with a strength retention rate of above 80%, and demonstrated that ozone can be used on polyester fabric and dye simultaneously. The aim of entering the fibre was achieved by etching the polyester and decolorisation was achieved by oxidising the chromaticity groups. [ABSTRACT FROM AUTHOR]

We have designed and prepared four new cellulose cross-linking agents using NaClO/NaBr/TEMPO and sodium periodate selective catalytic oxidation systems. First, the primary hydroxyl group of sucrose, trehalose, maltose, or lactose was carboxylated through NaClO/NaBr/TEMPO system, and then sodium periodate was used to selectively oxidize the carboxyl compound to obtain carboxyl polyaldehyde sugars. They contained multiple aldehyde groups and carboxyl groups in the molecule, had high reactivity, and can be covalently cross-linked with cellulose. To evaluate crosslinking ability, carboxyl polyaldehyde sugars were applied to the anti-crease finishing of cotton fabrics. The treated cotton fabric had superior anti-crease and hydrophilicity properties, and the crease recovery angle reached more than 260°, wetting time was less than 5 s. Possible crosslinking mechanisms of etherification and esterification under different catalysts and curing temperatures have been studied. [ABSTRACT FROM AUTHOR]

In anti-crease finishing, the hydrophilicity of cotton fabric treated with traditional anti-crease finishing agents such as dimethylol dihydroxy ethylene urea (DMDHEU), 1,2,3,4,-butanetetracarboxylic acid (BTCA), citric acid (CA) was reduced significantly. Oxidized sucrose (OS) was prepared by partial oxidation with sodium periodate. The OS was used as a hydrophilic cross-linking agent instead of conventional anti-crease agents. The chemical structure of the OS characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance, and aldehyde groups were found in the OS. The effects of OS mass concentration, catalyst mass concentration, pH, curing temperature and curing time on the crease recovery angle (CRA), whiteness index (WI) and strong retention rate (TS %) of fabrics were studied. The optimal finishing process was an OS mass concentration of 150 g/L, a catalyst mass concentration of 20 g/L, pH 3 and curing for 3 min at160°C. The OS-treated cotton fabrics could obtain a maximum CRA of 245°, WI of 82.8 and TS% of 65%. Compared with DMDHEU, glutaraldehyde, BTCA and CA finishing fabrics, the OS finishing fabric had a shorter wetting time of 5.01 s and a higher water retention. [ABSTRACT FROM AUTHOR]

Polyaldehyde trehalose (OTr) was prepared and applied to cotton fabric as an anti-crease finishing agent under Lewis acid conditions. OTr contains reactive groups (aldehyde groups) and hydrophilic groups (hydroxyl groups). After the aldehyde groups crosslink with the hydroxyl groups of the fibers, the hydroxyl groups of the OTr improve the hydrophilicity of the finished fabric. The target product was characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. The optimum process conditions for anti-crease finishing were studied. The optimal anti-crease finishing process for OTr was 10.0%, a MgCl2 concentration of 2.0%, a pH of 3, and curing for 3 min at 150℃. The efficiency of the OTr-treated cotton fabrics was examined, and the anti-crease property, whiteness, tensile strength, hydrophilicity, and staining property of the OTr and conventional anti-crease finishing reagents were compared. The anti-crease property, whiteness, and tensile strength of the OTr-treated fabric improved significantly, but were lower than those of the butane tetracarboxylic acid and glutaraldehyde. Fabric that was treated with the new prepared agent presented a satisfactory hydrophilicity, which indicates that OTr can be used as an effective hydrophilic crosslinking agent. [ABSTRACT FROM AUTHOR]

Traditional degumming of bast fibers results in problems such as environmental pollution and inferior fiber quality. For these reasons, biodegumming was considered as a potential process for bast fibers. In biodegumming process, decomposition of noncellulosic components was the pivotal problem. In this manuscript, the bast fiber of Apocynum venetum was processed with combinatorial processing, containing physical, chemical and microbial effect. The structural bio-recalcitrance was analyzed at molecular, supermolecular and morphological level in each stage. The results show that main substance in recalcitrance of Apocynum venetum bast is lignin and hemicellulose. And the protein and wax is also the constituent of bio-recalcitrance. The recalcitrance in the bast tissue can be divided into three layers. The spatial structure and the distribution of the noncellulosic substances also contribute to the recalcitrance. This paper provides directions for pretreatment design to render biomass more amenable to bioprocessing. [ABSTRACT FROM AUTHOR]