Preparation And Properties Of High Yield Nanofibers And NFs- Polymer Composites

Nowadays, NFs have a promising application prospect in many areas, due to its high surface energy, high activity and great surface area. Therefore, it draws a lot of attention to research NFs. In this paper, NF is prepared by Zn Cl2 aqueous solution pretreatment and mechanical treatment by raw material of bleached softwood pulp. The NFs- epoxy composites is prepared by combining the NFs suspension and epoxy resin, and the NFs- SBR composites is prepared by mixing the NFs suspension and SBR. The impact of NFs is analyzed on the properties of polymer materials. The NCC mask base materials are prepared, characterized and analyzed. The main results are as follows:1.With bleached softwood pulp as raw material, NF is prepared with Zn Cl2 aqueous solution pretreatment and mechanical treatment. The optimal conditions for producing NFs are obtained through the single factor method, the fiber concentration is 1.5%, the chemical pretreatment time is 2.5 h, the mechanical processing time is 25 min and the yield is 75%.2.The NFs are characterized and analyzed with Fourier transform infrared spectroscopy( FTIR), X-ray diffraction(XRD), Transmission electron microscopy(TEM) and TGA. It is found that the crystal of cellulose converted from CelluloseⅠto CelluloseⅡduring the process of Zn Cl2 aqueous pretreatment and the functional group structure did not change significantly. The average diameter of the NFs is about 10 nm. Compared with raw fibrils, the NFs thermal stability is slightly higher.3.NFs of ethanol dispersion is mixed into the Epoxy ethanol- polyamide resin solution. The NFs- epoxy composites is prepared through evaporating the solvent. The effect of NFs adding amount on the mechanical properties of composites is analyzed in this paper. The NFs-epoxy composite is also characterized with SEM and FT-IR. It is found that the NFs are evenly distributed in the epoxy resin. With the increase of NFs content, the elongation of NFs- epoxy composites increases. When the content of NFs is less than 7.5%, the tensile strength increases, and when the content of NFs is more than7.5%, the tensile strength decreases.4.NFs of ethanol dispersion is mixed into the SBR solution. The NFs- SBR composite is prepared through evaporating the water. The effect of NFs adding amount on the mechanical properties of composites is analyzed in this paper. The NFs-SBR composite is also analyzed with SEM and FT-IR. It is found that the NFs are evenly distributed in the SBR. When the content of NFs reaches 15%, the breaking elongation of the composite material reaches 162%.5.The mask base is prepared by NFs. The different mask bases are characterized with SEM. The maximum water absorption and water retention are also analyzed. The thickness of mask is moderate and the mask is gelatinous. The saturated water absorption is 1400%, which means that amount of water absorption is absolutely 14 times of the dry base. The water retention rateis 75% after exposing in the air for 60 min. The essence adsorption ability is pretty well. The adsorption capacity of starch solution with viscosity of 6 MPa·s is 85%.