The Regenerated Fiber Cellulose Extracted From Cotton Stalks Resources Based On Organic Solvent Method

In recent years, with the reduction of arable land, increasing depletion of coal, oil, natural gas resources, which gradually limiting the production of natural fibers and synthetic fibers; due to the wide regenerated cellulose sources, there is regeneration characteristics, but also has excellent application performance synthetic fiber is difficult to replace, so that people attach importance to textile consumption while regenerated cellulose fibers for a long exploration of the development. Crop straw is the most abundant of inexhaustible renewable resources in the nature to provide raw materials for the regenerated cellulose, with large output, short production cycle characteristics.With the growing awareness of environmental protection, therefore we use environmentally friendly and high separation method to get the purity of cellulose pulp is the key to get the biomass raw materials high value. With cotton stalk powder as raw materials, extraction of cellulose dissolving pulp for recycled fiber by organic solvent.At first, formic acid pretreatment of the raw material to remove hemicellulose, to study the effects of different acid concentration, temperature and time on the yield, morphology and structure, etc. Secondly, the cooking process to remove lignin by organic solvent, in the process study the degree of vulcanization, ethanol concentration, cooking time, temperature and amount of surfactant and other factors, by the analysis of the Kappa number of the pulp, the yield and morphology to get the optimum ethanol cooking. The optimum conditions for the ethanol cooking process: sulfidity 23%, ethanol concentration of 50%, cooking temperature 150 ℃, holding time 2h, bath ratio of 1:10, the amount of surfactant is 0.5%. Results were obtained: the temperature is too low, lignin removal is not sufficient, the temperature is too high, cellulose degradation is more serious; the highest temperature holding time should not be too long, too long will damage cellulose, also causing re-deposition of lignin.In order to further remove lignin and reduce the burden of the bleaching step, The pretreated feedstock,after cooking, washing with an organic solvent under the conditions of weak acid to remove lignin deely. In the washing process, effects of alkali dosage, bath ratio, temperature and time on the pulp kappa number, yield andmorphology, resulting in optimum organic solvent washing, which is: alkali charge 2.5%, bath ratio 1:15, washing temperature 150 ℃, heat preservation time 60 min. The results show that: the base excessive use can cause a lot of cellulose degradation, excessive washing temperature due to the large temperature difference during vacuum filtration leads to the deposition of lignin again.In order to obtain cellulose dissolving pulp for recycled fibers, bleaching based on organic solvent pulping in this paper. After bleaching experiments, obtain the optimum conditions were: temperature 80 ℃, the amount of hydrogen peroxide 7%, bath ratio 1:20. After the best bleaching process, holocellulose 95.6%, α- cellulose 78.9%, pentosan10.2%, acid insoluble lignin 2.9%, ash 1.4%, intrinsic viscosity 5.024, the degree of polymerization 832.8 in samples. Cotton stalk powder after each optimum treatment to get the final dissolving pulp, and try to spinning.