A kind of method for mechanically activating solid phase reaction to prepare lignin ester

Abstract

The invention discloses a method for preparing lignin ester by mechanical activation-solid reaction. The method comprises the following steps of weighing reaction materials according to the ratio of lignin to an acylating agent to a catalyst is 15g: 0.08-0.6mol: 0.15-6.7g; placing the reaction material in a ball mill; performing thermostatic waterbath at the temperature of 50-90 DEG C; stirring at the low rotating speed of 100-500 r / min and performing acylation for 0.5-4 hours to obtain crude products of the lignin ester; separating the crude products from pellets; placing the crude products of the lignin ester in solvent and standing to separate out solid; separating the solid from the solvent by filtering; and removing the acylating agent and the catalyst by using a solvent repeated washing and filtering method or an extraction method to obtain lignin ester products. The lignin ester is synthesized by mechanical activation-solid synthesis, the shortcoming that activity of chemical reaction of lignin is low is overcome, and problems existing in preparation of the lignin ester by the traditional liquid-phase method are solved. The method has the advantages that the method is pollution-free and low in cost; reaction materials are mixed fully; equipment cost is low; energy consumption is low; reaction time is short; modified lignin is easy to recycle; a producing and preparing technology is simplified; and the method is easy and convenient to operate.

Description

technical field [0001] The invention relates to a method for preparing lignin esters, in particular to a method for preparing lignin esters by mechanically activating solid phase reaction. Background technique [0002] Lignin is an amorphous, aromatic polymer containing oxyphenylpropanol or its derivatives in its molecular structure widely present in plants. Lignin is the only renewable aryl compound that nature can provide, and its content in land plants is second only to cellulose. According to statistics, at present, the global annual lignin production is about 6×10 5 billion tons, and lignin is regenerated at a rate of about 50 billion tons per year. Although lignin has many characteristics such as wide sources, rich active groups, biorenewability and degradation, non-toxic weather resistance, thermoplasticity, glass transition, etc., the current utilization rate of industrial lignin is less than 20%, and most of lignin is used as waste Emissions, waste of resources, ...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to overcome the problems that lignin has low reactivity, is difficult to directly modify and utilize, and the synthesis of lignin ester is difficult to realize industrial production.

At the same time, it also solves the above-mentioned chemical modification methods that require a large amount of solvent, difficult solvent recovery, environmental pollution, catalyst residue, complex process and high cost, long time for acylation of lignin, time-consuming and locked-in equipment for recovery of modified lignin Problems of high cost, insufficient mixing of reaction materials and complicated operation

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