# Improving the Dyeability and Anti-Wrinkle Properties of Cotton Fabric via Oxidized Raffinose
###### Abstract  
In the anti-wrinkle finishing of cotton fabrics, the decreased dyeability of the finished fabrics has always been a difficult problem. A new anti-wrinkle finishing mode was developed to solve this problem by changing the finishing sequence of fabric dyeing and anti-wrinkle. In this research, the partial oxidization of raffinose with sodium periodate generated multiple aldehydes, which acted as multifunctional cross-linkers and endowed cotton fabrics with anti-wrinkle and hydrophilic properties. The structural characteristics of oxyRa were analyzed by FTIR and \({}^{13}\)C-NMR. Through response surface methodology (RSM), the finishing model of oxyRa was established from the influencing factors of catalyst concentration, pH, curing temperature and time, and the optimized finishing process: the catalyst concentration was 20.12 g/L, pH was 4.32, curing temperature was 150 \({}^{\circ}\)C and curing time was 120 s. Under this condition, the predicted wrinkle recovery angle (WRA) of the finished fabric was up to 249.76\({}^{\circ}\), Tensile strength (TS) was 75.62%, Whiteness index (WI) was 70.69. Importantly, comparing the anti-wrinkle and dyeing performance of the fabric with anti-wrinkle and then dyeing and anti-wrinkle after dyeing, the oxyRa-treated fabrics showed better dyeing properties compared with previously reported dimethylhydroxyethylene urea (DMDHEU), glutaraldehyde(GA), and 1,2,3,4-butanetetracarboxylic acid (BTCA). Analysis of the combined mechanism of different finishing agents and cellulose, demonstrated the reason why oxyRa can be used to change the order of dyeing and anti-wrinkle finishing. oxidized raffinose; polyaldehyde derivatives; anti-wrinkle finishing; dyeing; RSM; cotton fabric +
Footnote †: journal: Medical  
cotton fabric anti-wrinkle properties. In the finishing process, the micro-pore size and internal surface area of the fiber are reduced, resulting in a decrease of the hydrophilicity and dyeability [9; 10; 11]. Therefore, anti-wrinkle finishing is usually carried out after dyeing or printing. In order to adapt to the trend of the clothing market toward small batch and multi-variety development, it is required that the dyeing process can be carried out after anti-wrinkle finishing. Therefore, it is necessary to develop a new type of anti-wrinkle finishing agent, which can greatly improve the hydrophilicity and dyeability of the finished fabric. Raffinose is the most well-known trisaccharide in Nature, being widely found in natural plants and in many vegetables (cabbage, cauliflower, potato, beet, onions, etc. ), fruits (grapes, bananas, kiwi, etc. ), rice (wheat, rice, oats, etc.). The seeds of some oil crops (soybeans, sunflower seeds, cottonseeds, peanuts, etc.) also contain varying amounts of raffinose. Raffinose is composed of galactose, fructose and glucose. To our knowledge, sodium periodate selectively cleaves the vicinal hydroxyls in carbohydrates to yield aldehyde groups [5; 12; 13; 14; 15]. The aldehyde group can be used as the reactive group to combine with the hydroxyl groups of cellulose to achieve anti-wrinkle properties. At the same time, the hydroxyl group of raffinose is introduced into the fiber as the reaction progresses to improve the hydrophilicity and dyeability of the finished fabric. Based on this mechanism, we have established the idea of changing the sequence of anti-wrinkle and dyeing finishing. In this study, raffinose was partially oxidized by sodium periodate to obtain oxyaffinose (oxyRa), which was applied as an anti-crease finish for cotton fabric. The aldehyde content of oxyRa was titrated with hydroxylamine hydrochloride, and the structural characteristics were analyzed by FTIR and \({}^{13}\)C-NMR. The optimized finishing process was established through response surface methodology (RSM), the four influencing factors being catalyst concentration, pH, curing temperature and time.