木素用于酚醛树脂胶黏剂改性

Modification of Phenol Formaldehyde Resin Adhesive Using Lignin

采用酸析法回收得到的木素为原料,替代部分苯酚与甲醛反应制备木素改性酚醛树脂胶黏剂,并测定其固含量、动力黏度(40℃)、游离甲醛含量和胶合强度等性能。主要考察了木素/酚化木素掺入比例、催化剂(碱)种类及用量、酚醛摩尔比以及反应温度对胶黏剂性能的影响。结果表明,合成木素酚醛树脂胶黏剂较佳的工艺条件为:木素掺入比例5%～15%(质量百分数,以苯酚质量为基准),酚醛摩尔比1:1.5,催化剂为NaOH,加入量0.6%(质量百分数,以苯酚质量为基准),反应时间3h。采用酚化木素时,掺入比例可达45%,制得胶黏剂性能优于纯木素。木素替代部分苯酚改性酚醛树脂胶黏剂,不仅可以降低生产成本,而且更环保。

Phenol was partially replaced by lignin to prepare modification lignin-phenol-formaldehyde（LPF） adhesive,which was extracted from the pulping black liquor with nitrate acid.The properties of above adhesives were determined,such as solid content,dynamic viscosity（40℃）,free formaldehyde content and bond strength.The effects on properties of LPF resin were studied,for example,lignin/phenolation lignin content,species catalysts,catalytic use level,reaction time and the ratio of phenol to formaldehyde etc.As a result,the better process conditions for synthesis LPF were that the mixing quantity of lignin was 5%~15%（based on the mass of phenol）,the catalyst was NaOH and its addition quantity was 0.6%（based on the mass of sodium hydroxide）,the mol ratio of phenol to formaldehyde was 1：1.5 and the reaction time was 3h.When phenolation lignin was used,the mixed quantity was up to 45%,the properties of obtained adhesives were better than that of pure lignin.Using lignin replaced partially phenol not only the production costs were decreased,but also that was favorable for environment.