Research On The Extraction And Regeneration Spinning Of Microfibers From Rice Straw, Bamboo And Wheat Straw

Lignocellulose is a renewable natural biomass resource with a wide range of sources and abundant resources,but due to its complex structural characteristics,the current resource utilization rate is low.Therefore,pre-treating straw fibers to obtain straw microfibers with higher cellulose content can effectively increase the utilization range of lignocellulose.This article uses a combination of sodium hydroxide treatment and low temperature treatment to treat rice straw,bamboo flour and wheat straw,and explores the rules of its effect on the cellulose,hemicellulose and lignin content in the wood straw fiber,so as to obtain the optimal process of wood straw microfiber with high cellulose content.The obtained wooden straw microfibers are blended with pulp and dissolved and wet spinning to obtain regenerated cellulose fibers.This article used sodium hydroxide pretreatment combined with low-temperature solid-liquid critical phase to treat rice straw,to study the effect of sodium hydroxide pretreatment mass fraction,temperature and time on the components of cellulose,hemicellulose and lignin in rice straw.The results showed that the rice straw was treated with 9% sodium hydroxide solution at 90°C for 60 min.After cooling,the treatment was performed at the critical temperature of the solid-liquid phase.The microfiber product obtained had the highest cellulose content of 85%;The hemicellulose composition is 7.1%;the lignin composition is 6.1%.The SEM image shows that after pretreatment,the hemicellulose and lignin wrapped on the surface of rice straw microfibers are removed,and the diameter of the microfibers is below 5?m.Through XRD spectrum and TG curve,it was found that the cellulose crystalline form of rice straw changed from cellulose I to cellulose II,because the cellulose had mercerized under low temperature alkaline solution.The thermal stability of rice straw microfibers is increased.This article used sodium hydroxide pretreatment combined with low-temperature solid-liquid critical phase to treat bamboo powder,to study the effect of sodium hydroxide pretreatment mass fraction,temperature and time on the components of cellulose,hemicellulose and lignin in bamboo powder.The structure and properties of bamboo microfibers were characterized by scanning electron microscope,X-ray diffractometer and thermogravimetric analyzer.The results showed that the bamboo powder was treated with 9% sodium hydroxide solution at 90 ° C for 60 min,and then treated with the lowtemperature solid-liquid critical phase.The content of the cellulose component in the resulting product was the highest at 74.8%;the hemicellulose component was 10.1%;lignin content is 12.1%.When bamboo fibers are processed at low temperature,the hydroxide ions in the alkaline solution can expand the swelling between bamboo microfibers,which is beneficial to the removal of hemicellulose and lignin under the action of shear external force.In the SEM picture,a large number of flakes on the surface of bamboo microfibers were removed,and the microfibers were dispersed.The cellulose I crystal form was converted into cellulose II crystal form before and after pretreatment.The thermal stability of bamboo microfibers has improved.This article used sodium hydroxide pretreatment combined with low temperature solid-liquid critical phase to treat wheat straw,and studied the mass fraction,temperature and time of sodium hydroxide pretreatment on the components of cellulose,hemicellulose and lignin in wheat straw.And the structure and performance were characterized.The results showed that the wheat straw was treated with 7% sodium hydroxide solution at 90 °C for 60 min,and then treated at low temperature.The resulting product had the highest cellulose content of 70.0%;hemicellulose content of 8.8%;lignin content of 12.2 %.After the treatment,the overall structure of the wooden straw microfibers becomes loose from the density before the treatment,and the microfibers are scattered and bent.The cellulose in wheat straw belongs to natural cellulose,and the micro-fiber of wheat straw obtained after pretreatment shows the characteristic crystal form of cellulose II.The TG curve shows that the solid residual mass of wheat straw microfiber is lower than that of wheat straw.The best product obtained from the treatment of rice straw with sodium hydroxide treatment and low-temperature solid-liquid critical phase treatment of rice straw microfibers and pulp was dissolved and blended by the alkali-urea method,and regenerated cellulose fibers were obtained by wet spinning.The prepared regenerated cellulose fibers were tested and characterized by infrared spectrometer,scanning electron microscope,thermogravimetric analyzer and single fiber strength meter.The surface of blended regenerated cellulose fiber is smooth and without cracks,and the cross section is nearly circular.Raw cellulose fibers have good thermal stability.Compared with pulp regenerated cellulose fibers,the breaking strength of blended regenerated cellulose fibers is reduced.When the mass ratio of rice straw microfiber to pulp is 2: 8,the water absorption rate of blended regenerated cellulose fiber is the highest,reaching 121.7%.