Catalytic Oxidation Degradation Of Lignin And Its Application

The pulp and paper industry produced million tons of extracted lignin as by-products,but the markets for lignin products remain to explore.And current market focuses on effective degradation of lignin and its application.In this thesis,lignosulfonate was treated with Dragon/H₂O₂ and this technology is transferred on delignification of bagasse to produce the cellulose powder in the end.In the degradation of lignosulfonate,the influence of reaction time and temperature,the different dosage of Dragon as catalyst,the different dosage and concentration of H₂O₂ as oxidant,the influence of pH value of the solution are discussed.The degradation of lignosulfonate during this process was tracked and investigated by UV-Vis,IR,1H NMR spectroscopy and HPLC method.The degradation of the model compound-Ferulic acid in the Dragon/H₂O₂ system was also studied.The result showed that by the treatment of Dragon/H₂O₂ system,the degradation ratio of lignosulfonate reached 90%and the benzene rings of lignosulfonate were destroyed to formed small molecular products such as carbon dioxide and water as resultant products.Then,transfer the technology to delignification of bagasse.The cellulose powder was produced from bagasse waste,through the procedures of pre-treatment,the degradation of lignin in bagasse,the degradation of cellulose,filter wash,drying and pulverization are discussed.Finally the delignification of bagasse was 95%,the yield of cellulose was 83%and the holding water ability of the product was 10g/g.The delignification of wood fiber materials by Dragon/H₂O₂ system was not effective,but it was appropriate to delignification of none-wood fiber materials without damaging the cellulose.At last,prepare a PP/lignin composite material to further develop the application of lignin.In the composite material by adding compatibility agent PP-g-MAH,the problems of the poor interfacial compatibility between matrix and enhanced phase was solved.And the effect of adding titanium potassium whisker on the comprehensive mechanics performance and toughening agents POE-g-GMA on the toughening effect of the composite materials are discussed.