酚化酶解木质素-环氧树脂/环氧树脂复合材料的合成及性能
Synthesis and properties of phenolic modified enzymatic hydrolysis lignin-epoxy resin/epoxy resin composites

以酶解木质素（EHL）为原料，采用苯酚-硫酸法对其进行酚化改性，所得酚化木质素（PL）在碱性条件下，与环氧氯丙烷（ECH）合成木质素-环氧树脂（L-EP），利用FT-IR对产物进行表征。探讨单因素反应条件对酚化工艺的影响。结果表明：反应时间3.0 h、反应温度95℃、2 mol/L H2SO4用量为4 mL/g时，木质素的酚化效果最佳，其酚羟基含量达到4.632 mmol/g，较EHL提高42%。研究了不同L-EP添加量对L-EP/环氧E-51复合材料力学性能和热性能的影响。结果显示：L-EP的添加量为5%时，L-EP/环氧E-51复合材料的拉伸强度最好，较纯E-51提高26%；随着L-EP添加量的增加，L-EP/环氧E-51复合材料的热稳定性增强。采用非等温法分析环氧E-51和L-EP/环氧E-51复合材料的固化动力学，结果证明：L-EP对复合材料固化有一定的促进作用。 With the enzymatic hydrolysis lignin (EHL) as the raw materials, and the phenol-sulfuric acid method was used to modify EHL. Under alkaline conditions, the lignin-epoxy resin (L-EP) was synthesized by phenolated lignin (PL) reacted with epichlorohydrin (ECH). The structure of EHL and its modification and the synthetic resin were analyzed by FT-IR. The effects of single factor reaction conditions on the process of phenolation were discussed. The results indicate that the effect of modification is the best under the condition of 3.0 h, 95℃ and 4 mL/g H2SO4 (2 mol/L), and the content of phenolic hydroxyl group reaches 4.632 mmol/g, which increases by 42% compared with EHL. The effects of different L-EP adding amount on the mechanical properties and thermal properties of L-EP/epoxy E-51 composites were investigated. The results show that the tensile strength of L-EP/epoxy E-51 composites is the best when the amount of L-EP is 5%, which increases by 26% compared with that of the pure E-51 epoxy resin. With the increase in the amount of L-EP, the thermal stability of L-EP/E-51 composites is enhanced. The non-isothermal method was used to analyze the curing kinetics of epoxy E-51 and L-EP/E-51 composites. The results reveal that L-EP has a certain effect on the curing of L-EP/epoxy resin composites. 国家林业局科学技术计划（2015-4-55）；国家自然科学基金（31200451）