Modified lignin, preparation method and application of modified lignin in toughening flame-retardant composite material

Abstract

The invention discloses modified lignin, a preparation method and application of the modified lignin in toughening flame-retardant composite materials, and belongs to the field of flame retardants andbio-based flame-retardant materials. The preparation method comprises the following steps of: adding melamine and formaldehyde into water according to a mass ratio of 1: (0.08-0.5), and carrying outa stirring reaction for 0.5-2 h at a temperature of 60-90 DEG C; gradually adding the alkaline lignin, formaldehyde and phytic acid into the solution obtained in the step (1) according to the mass ratio of (0.25-2): (0.13-1.0): (0.25-2): 1, reacting for 3-5 hours at the temperature of 50-90 DEG C, filtering and drying to obtain modified lignin; and blending polymer resin, modified lignin and a plasticizer to obtain the toughened flame-retardant composite material. The preparation method of the modified lignin toughened flame-retardant composite material is high in production efficiency, simplein process, excellent in performance, environment-friendly and easy to realize industrial production.

Description

technical field [0001] The invention belongs to the field of bio-based polymer materials, and in particular relates to a method for preparing a toughened and flame-retardant composite material based on modified lignin, a preparation method and its application. Background technique [0002] Lignin is abundant in nature and is the second most abundant natural polymer after cellulose. It mainly comes from the waste liquid of paper mills. At present, most of it is used as fuel, and only a small part is used as fuel. Chemical products cause a great waste of resources. The basic structural unit of lignin is phenylpropane, including: guaiacyl propane, syringyl propane and p-hydroxyphenyl propane; in addition, many functional functional groups are connected to the lignin structural unit, such as benzene ring, phenolic hydroxyl group, alcohol Hydroxyl group, carboxyl group, methoxy group, conjugated double bond, etc., which make lignin have strong reactivity and provide the possibil...

AI Technical Summary

Problems solved by technology

[0003] Lignin molecules are prone to agglomeration due to their own chemical bonds, and their dispersion in the matrix is ​​poor, resulting in poor performance of composite materials

In addition, there are more hydroxyl functional groups on the surface, which can easily cause the degradation of polyester polymer materials and cause the polymer to become brittle

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