Preparation of Lignin-Based High-Ortho Thermoplastic Phenolic Resins and Fibers

Molecules

Can Liu¹  Jin Xie¹  Yu Ren¹  Rui Shi²  Xiahong He² 

[1] Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, College of Materials Science and Engineering, Southwest Forestry University, Kunming 650224, China;Key Laboratory of State Forestry Administration for Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, Southwest Forestry University, Kunming 650224, China;

关键词: lignin;    thermoplastic phenolic resin;    high-ortho;    phenolic fiber;    thermal stability;   

DOI  :  10.3390/molecules26133993

来源: DOAJ

【 摘 要 】

Surplus lignin, which is inefficiently used, is generated in the forestry industry. Currently, most studies use lignin instead of phenol to synthesize thermosetting resins which cannot be reprocessed, thus affecting its application field. Thermoplastic phenolic resin has an orderly structure and excellent molding performance, which can greatly improve its application field and economic value. Herein, phenol was partially replaced with enzymolysis lignin (without treatment), generating lignin-based high-ortho thermoplastic phenolic resins (LPRs), and then lignin-based phenolic fibers (LPFs) were prepared by melt spinning. FTIR, ¹³C-NMR and GPC were used to characterize the ortho–para position ratio (O/P value), molecular weight and its distribution (PDI), and rheological properties of the resin. TG, XRD, SEM and tensile property studies were used to determine the thermal stability, orientation, and surface morphology of the fiber. Lignin addition resulted in the decline of the O/P value and molecular weight of the resin. For the 10% LPR, the O/P value, Mw, and PDI were 1.28, 4263, and 2.74, respectively, with the fiber exhibiting relatively good spinnability. The tensile strength and elongation at break of the 10% LPF were 160.9 MPa and 1.9%, respectively. The addition of lignin effectively improved the thermal properties of the fiber, and the carbon yields of 20% LPF before and after curing were 39.7% and 53.6%, respectively, which were 22.2% and 13.7% higher than that of the unmodified fiber, respectively.

【 授权许可】

Unknown