木质素基阻燃剂的研究进展

Research Progress on Lignin-based Flame Retardants

木质素化学结构中含有丰富的碳原子,其本身可作为高分子材料中的填料,在高分子材料燃烧过程中提供碳源并促进阻燃;木质素的分子结构含有芳香基、酚羟基、醇羟基等活性基团,通过化学改性将具有阻燃作用的元素或基团引入到木质素的化学结构中,可以获得一系列木质素基阻燃剂。本文从木质素结构入手,概述了国内外未改性木质素,氮、磷改性木质素和掺入金属铜或非金属硅的氮磷改性木质素在不同聚合物材料中做阻燃剂的研究进展,包括物理协同阻燃配方、化学改性制备方法、处理前后的阻燃效果对比。同时,解释了相应阻燃剂的阻燃机理,包括:释放出的不可燃气体对氧气的隔绝作用,形成致密不可燃炭层,以及对热量传递的阻碍作用等。并对木质素基阻燃剂的应用前景进行了展望。

Lignin contained abundant carbon atoms in its chemical structure,which could be used as filler in polymer materials to provide carbon source and promote flame retardant in the combustion process of polymer materials.The molecular structure of lignin contained active groups such as aromatic group,phenolic hydroxyl group and alcohol hydroxyl group.A series of lignin-based flame retardants could be obtained by introducing flame retardant elements or groups into the chemical structure of lignin through chemical modification.Starting from the structure of lignin,this paper summarized the domestic and foreign research progress of unmodified lignin,nitrogen and phosphorus modified lignin,and nitrogen and phosphorus modified lignin doped with copper or non-metallic elements like silicon as flame retardants in different polymeric materials,including physical synergistic flame retardant formulations,chemical modification preparation process and the comparison of flame retardancy effect before and after treatment.The flame retardant mechanism of the corresponding flame retardants was analyzed,including the oxygen isolation effect by the released non-combustible gas,the formation of dense non-combustible carbon layer,and the hindering effect on heat transfer.Additionally,the application prospect of lignin-based flame retardants was prospected.