| Hemp can be made clothing after degumming, yarn, weaving and dyeingprocessing, and so on. Due to the special structure and chemical composition of hemp,removing all of gum from hemp is very difficult. And, if all of gum have beenremoved, it is easy to cause hemp excessive damage. If hemp degummed not fully,the hemp fiber coarse large diameter and hardness, separating yarn and weaving withhemp will more difficult, made of hemp cloth uneven dyeing, dyeing rate is not high,and dyeing the dark and the bright color more difficult, which is currently the mainproblem on study of hemp.This topic using chitosan (CTS) and glycine hydrochloride([Gly]Cl) ionic liquidjointly processed hemp, hemp have been further modified and certain improvementsin the structure, it wrinkle resistant, stain and antibacterial performance also has beenimproved. This paper begun from synthesizing of [Gly]Cl, discussed every singlefactors to influence [Gly]Cl synthesis and determined the optimal process conditions:reaction temperature for60℃, reaction time for6h, hydrochloric acid and glycine inthe molar ratio for1.4, The synthetic product for [Gly]Cl by Fourier transforminfrared spectroscopy (FTIR). The result of dissolution experiment showed that[Gly]Cl have a well solubility to CTS, and compared with the performance ofdissolution between [Gly]Cl and acetic acid, it shows that the quantity of [Gly]Cl wasrequired less than acetic acid when the mass fraction of CTS was under2%,on thecontrary, when the mass fraction of CTS was above2%, the quantity of acetic acidwas required less than [Gly]Cl.In the [Gly]Cl ionic liquid assisted by oxidative degradation of chitosanexperiment. The reaction condition was optimized by orthogonal experiment on thebasis of single factor experiment. The optimum condition was: reaction temperaturefor60℃, reaction time for2h, H2O2and CTS unit molar ratio for2, the mass fractionof CTS for3.5%,[Gly]Cl mass fraction for3%, then the product yield was84.5%, the molecular weight was0.66×104, and the product color was white, it conform with thefinishing of hemp fabric requirements. The structures of the three kinds of differentmolecular weight of CTS product were same with CTS by Fourier transform infraredspectroscopy. The results showed that the degradation of the molecular chains of CTSwithout chemical crosslinking reaction, and in the molecular structure hydroxyl notbeen oxidized to carboxyl, degradation process just made large molecules into smallmolecules of CTS.The surface of hemp fiber which were respectively processed by [Gly]Cl andCTS have " etching " effect, which can be seen from the chart of scanning electronmicroscopy. CTS was covered on the surface of hemp fiber.[Gly]Cl and CTS canmake the hemp fiber surface smoother. The effect of covering on Hemp with Lowmolecular weight CTS finished was better than large molecular weight CTS.Hemp fabric finished by CTS has a good effect of crease resistance, but itsstrength and whiteness was decreased. its capillary effect trend to decrease, thepermeability was increased. As CTS concentration increased after treatment, the hempfabric permeability first increases and then decreases.Hemp fabric finished by CTS dyeing performance improved significantly. Theoptimum finished condition was: the molecular weight of CTS was0.7×104, massfraction of0.6%, rolling remnant rate was100%, the baking temperature for80℃,baking time for5min, hemp fabric under this finished condition dyeing effect is best.And with the finished of CTS of hemp fabric in dyeing, can reduce about half the saltquantity. Its antibacterial performance was better than that haven’t finished, its havewell effect against Staphylococcus aureus and Escherichia coli inhibition, and thesmaller the components, the higher the concentration, the more strong antibacterialeffect it has. Hemp fabric that finished by the molecular weight antibacterial propertywas excellent, its durability was also very good, and its bacteriostatic rate still reachesmore than70%after been washed30times. |
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