摘要
采用场解吸质谱(Field Desorption-Mass Spectroscopy,FD-MS)表征了玉米芯木质素、麦秆木质素和混合木质素(玉米芯、秸秆等的混合物)3种不同木质素的结构;以磷酸为催化剂,在高温高压条件下用苯酚对木质素进行酚化改性,用FD-MS对木质素的酚化反应进行了研究。结果表明,FD-MS可以直观得到木质素各组分的分子质量及分子质量分布,木质素经酚化反应后分子质量减小,多分散系数减小,木质素中各个组分均参与了酚化反应,其中玉米芯木质素的酚化效果最好,经酚化反应后生成大量双酚F及其衍生物,酚化木质素具有与热塑性酚醛树脂相似的结构,采用该酚化木质素改性酚醛树脂发泡,制备的酚醛泡沫细腻,且韧性有明显提高。
The structures of three kinds of lignins （corn-cob lignin, wheat straw lignin and mixed lignin） were characterized by field desorption-mass spectroscopy （FD-MS）. These lignins were phenolated using phenol as the medium and phosphoric acid as the catalyst under high temperature-pressure condition. Then the three phenolated lignins were also measured by FD-MS. The results showed that FD-MS can be used directly for studying molecular weight and molecular weight distributions of lignins. After the phenolation,both the molecular weight and distribution of lignin decreased. All parts of lignin reacted with phenol during the phenolation. The corncob lignin has ＂the best phenolation effect, and the phenolated corncob lignin contains a lot of bisphenol F and its derivatives showing its structural similarity with Novolac. The phenolated corncob lignin can be used to modify phenolic foaming resin,the toughness of the prepared foam is improved obviously.
出处
《新型建筑材料》
2014年第9期70-74,90,共6页
New Building Materials
