Study On Cellulose Fibers Modified In Ionic Liquids

Cellulose is the most abundant natural organic matter, is a renewable resource, is biodegradable, cheap price, no environmental pollution, etc. Natural cellulose has high crystallinity and large numbers of intermolecular and intramolecular hydrogen bonds form a network structure, insoluble in water and general organic solvents. At present, most solvent that can dissolve cellulose is toxic. There are not easy to recycle, environmental pollution and other issues, which became the biggest obstacle to the development of cellulose.Ionic liquids have become a new green and environmental friendly solvent as new solvents of cellulose in recent years, because of their good solubility, a very low vapor pressure, non-combustible, non-volatile, no oxidation, good thermal stability and chemical stability, recyclable, etc advantages. They have got enormous attentions from scientists around the world.In this study, we use one-step method synthesis [Bmim]Cl ionic liquid, and lignocellulose pretreatment with a certain concentration of NaOH solution. Using the [Bmim]Cl ionic liquid to dissolve lignocellulose which has been done some pretreatment in the oil heating conditions bath, then prepared cellulose fiber by dry-wet spinning. Using glutaraldehyde cross-linked regenerated cellulose fiber. Cellulose and chitosan blend fibers prepared by mixing them together. We analyze cellulose by fourier transform infrared spectrometer(FT-IR), X-ray diffraction(XRD), thermogravimetry analysis (TGA), scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), light microscope and other means. And discuss the influence factors of the cellulose fibre preparation process and the precipitation rate of ionic liquid in the coagulation bath.The results showed that:cellulose in ionic liquids is direct physical dissolution and do not occur the derivatization reaction. The degree of polymerization of the alkali-treated wood cellulose decreased from610to527, the crystalline form from cellulose I to cellulose II. Regenerated cellulose thermal decomposition temperature decreases. Using dry-wet spinning successfully prepared cellulose fibers, the fiber surface is smooth, not seen the hole structure. Within the experimental range, the long dissolution time, high concentration of cellulose solution, long solidification time and low freezing temperatures are conducive to raising the strength of cellulose fibers. The strength of regenerated cellulose fibers by glutaraldehyde cross-linked has significant changes. These changes have a close relationship with glutaraldehyde concentration, the crosslinking temperature and crosslinking time. The best cross-linking conditions:glutaraldehyde concentration:4%, temperature:50℃, time:30min. In the preparation of chitosan/wood cellulose blend fibers, the addition of chitosan led to orientation and crystallinity of the fiber decline, resulting in strength reduced. Chitosan/wood fiber blend fiber surface appears obvious groove, and the groove was roughly longitudinal extension.