Phenolation And Oxidative Modification Lignin And Synthesis Of Lignin Adhesive

Along with the shortage of fossil resources, research and utilization of biomass energy attracting much more attention, in which high-value utilization of the lignin has a very positive meaning for development of new energy, alternative of chemical raw materials and environmental protection, because of the content of lignin is second only to cellulose, another natural polymer. Lignin mainly results from waste liquor of pulp and papermaking process. As a result of its low reactivity, lignin is difficult to be exploited directly and most of the lignin is burned to provide heat energy only, which lead to irrational utilization and great waste of energy. Therefore, research on the high reactivity of lignin has a very important and positive meaning for its high-valued utilization in the industrial production. In this paper, the lignin reactivity effects are studied through different ways of degradation, by dealing with lignin using liquefaction degradation method and oxidative degradation method respectively.Under conditions of phenol, in this paper we catalyze and liquefy degradation of lignin through way of a single variable. Different impacts on lignin degradation from various factors such as kind of catalyst, amount of catalyst, reaction temperature, reaction time are researched. Then depending on the content of phenolic hydroxyl from the degradation products, we arrive at a conclusion that the degradation effect of lignin will be the best while aluminum chloride is catalyst, while the addition amount of aluminum chloride is 5%, the reaction time is two hours and the reaction temperature for the degradation is 140 degrees centigrade.Under alkaline conditions, we use hydrogen peroxide and copper sulfate complex as a catalyst for lignin degradation by way of a single variable. Corresponding impacts on lignin degradation are studied as different factors like the concentration of catalyst, alkali concentration, reaction temperature, reaction time. Also according to the content of phenolic hydroxyl from the degradation products, we come to a conclusion that the effect oxydative degradation of lignin will be the best when the catalyst concentration is 7%, amount of alkali concentration is 5%, the reaction time is 2.5 hours and the reaction temperature for the degradation is 100 degrees centigrade.By analysing gel permeation chromatography results and the products under optimal reaction conditions for two kinds of degradation methods, the alkali lignin molecular in the catalytic process of phenol environment will turn into relatively small molecular. Lewis acid catalyzed degradation narrowed the range of alkali lignin molecular distribution and the chemical activity alkali lignin is more homogeneous when participating in the reaction. It is obtained that the linkage between alkali lignin units rupture and generate small molecule compound under aluminium chloride catalyst by nuclear magnetic resonance analysis while dealingeoxy group or demethoxy group reactions occur on the alkali lignin aromatic ring, resulting reduce the number of methoxy groups.Catalyzing and liquifying lignin under catalytic environment and under alkaline environment both improve the reactivity of lignin well, which providing new ideas for lignin using as raw materials in further industrial production and the efficient utilization of lignin.