Modification Of β-cyclodextrin And Its Application On Silk

Cyclodextrins(CDs) are macromolecular compounds with special hydrophobic cavities, which can include fragrance molecules,natural medicine molecules and anti-bacterial agent function compounds,etc.These kind of compounds can be used as ideal slow-release and controlled-release microcapsule wall materials.Up to now,CDs have been widely used in food industry,cosmetic field,drug delivery and textile industries.Since the German company Wacker developed a reactive aromatic agent called monochlorotriazinyl-β-cyclodextrin(MCT-β-CD) in 1996,CDs have been commercialized in the textile industry.So far,the CDs have been successfully used in cotton fabrics,but the application on silk has been rarely reported.The dissertation focused on the study of the modification ofβ-cyclodextrin and its application on silk fabric.As the silk is intolerant of strong acid and alkali,the pH value of the finishing conditions for silk fabric must below 10.5,which means that there must have highly reactive functional groups on CDs which could graft onto silk fabric.Three type reactive CDs were synthesized through experiments,includingα-bromoacyloylaminoethyl Cyclodextrin,cyclodextrins with ethilenic bonds and cyclodextrin with epoxy group.All of them can be grafted on silk with covalent bonds.Through the analysis of thin-layer chromatography,solubility testing, infrared spectroscopy and hydrogen nuclear magnetic resonance spectroscopy,it was proved that mono-(2-O-tosyl)-β-cyclodextrin(β-CD-2-OTs) could be synthesized in the aqueous solution of sodium hydroxide withβ-cyclodextrin and p-toluenesulfonyl chloride in a molar ratio of 1:6.2- ethylenediamio-β-cyclodextrin(β-CD-2-E) was synthesized under the reaction betweenβ-CD-2-OTs and ethylenediamine at the temperature above 60℃Mono-(2-(2,3-Dibromoacyloylaminoethyl)-2-deoxy)-Beta-cyclodextrin(β-CD-2-EDBA) was synthesized through the reaction betweenβ-CD-2-E and 2,3-Dibromopropionyl chloride. 2,3-Dibromopropionyl chloride must be dropped into the DMF(N,N-dimethylformamide) solution ofβ-CD-2-E at low temperature(0℃～5℃).The cyclodextrin monomer with ethilenic bonds Mono-(2-O-tosyl)-6-acryloyl-β-cyclodextrin(β-CD-2-OTs-6-A) and 6-acryloyl-β-cyclodextrin(β-CD-6-A) were respectively synthesized under the reaction between propylene chloride andβ-CD-2-OTs and the reaction between propylene chloride andβ-CD.Besides,Mono-(2-(N’-2,3-epoxypropylaminoethyl)-2-deoxy)-Beta-cyclodextrin(β-CD-2-EPA) was synthesized under the reaction betweenβ-CD-2-E and epichlorohydrin,the epichlorohydrin must be dropped into DMF solution ofβ-CD-2-E at low temperature(0℃5℃).And then the reagents were stir in 24 hours.The three types of cyclodextrin derivatives refer above and monochlorotriazinyl-β-cyclodextrin(MCT-β-CD) were used to graft on silk fabric.The optimal formulas for grafting CDs onto silk are recommended through lots of experiments.The optimal condition for graftingβ-CD-2-EDBA onto silk was prove to be:liquor ratio 1:50,sodium sulfate:8g/L,pH =9,grafting agent concentrationβ-CD-2-EDBA of 16%.o.w.f,treated 40 minutes under the conditions of 90℃.Through inclusion experiments,the fragrant pure silk which was treated byβ-CD-2-EDBA was proved to carry much more grass essence by inclusion than the original silk.And the fragrant pure silk was proved that it can keep a longer fragrance than the original silk.The most suitable pH value forβ-CD-6-A to be grafted on to silk fabric was proved to be 5.The optimal condition for graftingβ-CD-2-OTs-6-A onto silk was prove to be: monomer concentration of 20%.o.w.f,potassium persulfate of 1.85%.o.w.f,liquor ratio of 1:50,treated 30 minutes under the conditions of 80℃and at the pH value of 5.The optimal condition for graftingβ-CD-2-EPA onto silk was prove to be:monomer concentration of 15%.o.w.f,liquor ratio of 1:50,treated silk fabric 50 minutes under the conditions of pH=9 and 80℃.The optimal condition for grafting MCT-β-CD onto silk was prove to be:monomer concentration of 80 g/L,the concentration of sodium chloride of 60g/L,pH value of 8.5, treated 30 minutes under the conditions of 80℃.By comparing the phenolphthalein Spectroscopy and testing graft weight increase,phenolphthalein Spectroscopy was found to gain a higher grafting rate.But through analysis weight-testing method was proved to be more accurate.The scanning electron microscope picture has proven the monomer success stem grafting to the surface of silk.By comparing the grafting rate and the effect of scanning electron microscope photograph,β-CD-2-EDBA was proved to be the best monomer which could be grafted onto silk,followed byβ-CD-2-EPA.The grafting rate ofβ-CD -2-OTs-6-A andβ-CD-2-EPA were close.MCT-β-CD gained the lowest grafting rate.