Study On Methods Of Grafting β-Cyclodextrin Onto Fabrics

With the development of people's living standard, the requirement of the comfort and function of textiles increases. The post-treatment on textiles becomes one of the most important ways to improve the extra-value and multifunction of the products. Cyclodextrins are considered as very important environment friendly auxiliaries because they are biodegradable and no toxic symptoms. They are capable of forming inclusion compounds with molecules that fit into their cone-shaped hydrophobic cavity, such as essence, drug, etc. So, the fixation of cyclodextrins on textile materials leads to new quality of uses. Above all, we must deal with the problem that how to fix cyclodextrins onto fabrics permanently. In this paper, different methods were used to graftβ-cyclodextrin onto different fabrics.For wool fabrics, a new cyclodextrin derivative mono-6-(2, 3-Dibromopropionyl)-6-deoxy-β-cyclodextrin was synthesized. Its reactive group could react with amino group of wool. The target product was prepared via tosylation, azidonation, reduction and acylation from nativeβ-cyclodextrin. Every step's product was proved right by FT-IR and ¹H NMR. Due to the low productivity of the most important intermediate mono-6-(p-toluenesulfonyl)-β-cyclodextrin, an optimal method was obtained and the productivity was promoted to 35.51%. After grafting onto wool fiber, the cyclodextrin still could complex phenolphthalein, and decolorize the phenolphthalein dianion.For cotton fabrics, chemical and physical grafting methods, crosslinking by citric acid and anchoring by sol-gel solution respectively were used. Citric acid-β-cyclodextrin (CA-β-CD) was prepared using a semidry reaction method. The different factors affecting the carboxyl content of CA-β-CD were discussed and the optimal process was recommended: the mol ratio of catalyst SHP, citric acid andβ-cyclodextrin was 1:2:1, material to liquor ratio was 1:0.6, and the reaction was carried out under 100℃for 1 h. Compared with the grafting process in which citric acid was used as crosslinking agents for graftingβ-cyclodextrin onto cotton, the fabrics grafted with CA-β-CD had higher rate of grafting onto cotton. And they can also decolorize the phenolphthalein dianion. Nano TiO₂ sol solution was prepared by sol-gel method with Ti(OBu)₄ as precursor. The different factors affecting stability of sol solution were studied. The optimal formulas were obtained through particle diameter and UV transmittance analyzing, and the mol ratio of Ti(OBu)₄:C₂H₅OH:H₂O: diethanolamine was 1:10:2.4:1.β-cyclodextrin dissolved in DMF was added into the TiO₂ solution to form a mixture sol. Cotton fabrics treated with this sol could achieve good anti-ultraviolet performance and rate of grafting onto cotton but not affect the CIE whiteness. The surface of the fabrics was analyzed by ATR-FTIR, XRD, and SEM, the results showed thatβ-cyclodextrin was grafted onto fabrics successfully.