| Cellulose is the most abundant and most widely distributed natural biomass materials.Regenerated cellulose fiber products are mainly used in the manufacture of high-grade comfort functional clothing.Methanol is the representative product of coal chemical industry,and it is rich and inexpensive,which provides the resources for obtaining methanol protein.In this work,a methanol protein modified cellulose was obtained via copolymerization and/or blending of methanol protein,viscose and chain extender and further applied to the production process of viscose fiber to spinn a new type of protein modified cellulose fiber,a high-grade textile materials.Firstly,6 batches of fermentation experiments were carried out,and the fermentation process of preparation of methanol protein was summarized and analyzed.The product tracking and detection showed that the wet cell yield of each batch of the fermentation tank was 350-400 g/L,and the average was 374 g/L.The content of protein in crude protein was 56.9%.The crude product is purified by alkali solution,centrifugation,cell breaking as well as acid precipitation.The study of acid precipitation indicated that the yield of methanol protein reached the highest of 13%at pH of 4.Then,the modification of cellulose by methanol protein was studied from both aspects of kinetic and thermodynamic.The kinetic part includes two parts:the viscosity of the reaction system changes over time and the relationship between the rinsing times and protein residues.Four kinds of chain extenders were chosen including triglycidyl isocyanurate,glutaraldehyde,E51 epoxy resin,and 1,4-butanediol diglycidyl ether.The results showed that,the copolymerization reaction of the chain extender-solution of viscose-methanol protein ternary system happened in the first 40 min and has basically reached the chemical equilibrium within 1h.In addition to glutaraldehyde,the other chain extender(containing ethylene oxide functional group)system occurred a certain degree of three component copolymerization,that is,blending and copolymerization exist at the same time.In the thermodynamic part,the relationship between the properties and structure of the fibers was studied by means of nitrogen content,infrared spectrum,SEM,XRD and fiber mechanical test.The results showed that the mechanical properties of the fibers mainly depend on the crystallinity of the fibers and the chemical structure of the chain extender molecules.On the basis of the above research,the spinning process is optimized.The results showed that the optimum spinning conditions as follows:1,4-butanediol diglycidyl ether as the chain extender,the ratio of chain extender to methanol protein 1:9,and the pump intake was 20%of that of viscose.Finally,the antibacterial property of methanol protein modified cellulose fiber was improved by use of sodium alginate/calamine,to prevent the free proteins or peptides in the fibers from breeding bacteria.The results show that the use of sodium alginate/calamine alkaline hydrosol as dispersant can increase the settlement resistance of the dispersed powders,slow the sedimentation rate,and stabilize the powder dispersion.When 1 mol/L of sodium alginate alkali solution with a concentration of 10%calamine powder injected into the protein modified viscose spinning dope before spinning,the blend dope has a good spinnability,and the fiber herein spinned is of the best index and greatly improved antibacterial property. |
