木质素在溶剂体系中解聚及所得寡聚物的特性研究

Study on Depolymerization of Lignin in Solvent System and Properties of the Oligomer Obtained

中文关键词:  木质素  溶剂解聚  液相产物  寡聚物

Key Words:lignin  solvent depolymerization  liquid phase product  oligomer

中文摘要:

      以桉木有机溶剂木质素为原料，异丙醇/水作为溶剂，Ni-Ru/Hβ为催化剂，探讨了异丙醇/水体积比、反应温度及时间对木质素解聚液相产物转化率、单酚得率的影响；对液相产物进行溶剂分级萃取，得到富含寡聚物的组分，再结合气相色谱-质谱、电喷雾电离（ESI）源的高分辨率质谱、凝胶渗透色谱等表征手段，探究了木质素解聚液相产物中寡聚物含量及其结构特性。结果表明，将木质素在异丙醇/水混合溶剂（体积比3∶1）体系中于300℃下反应4 h，液相产物得率为81.0%，固相产物得率仅为11.3%，且液相产物中单酚得率为13.7%；从液相产物中所得两组富含寡聚物组分占液相产物质量的22.6%。

Abstract:

      Eucalyptus lignin was depolymerized using isopropanol/water as solvent， Ni-Ru/Hβ as catalyst and effects of isopropanol/water volume ratio， reaction temperature， and reaction time on the liquid product conversion rate and monophenol yield of lignin depolymerization were investigated. The liquid products were further separated by solvent sequential extraction to obtain oligomer-rich components， which were characterized by using GC-MS， ESI⁺-HRMS， GPC， etc.， to explore their contents and structures. The results showed that the product yields of liquid phase and solid phase were 81.0% and 11.3%， respectively， when eucalyptus lignin was treated in the isopropanol/water mixed solvent system with volume ratio of 3∶1 at 300℃ for 4 h， with yield of monophenol in the liquid phase product of 13.7%. It was noted that the two oligomer-rich components obtained from the liquid phase products accounted for 22.6% of their mass.