Institute of Hybrid Materials, College of Material Science and Engineering, Qingdao University, Qingdao 266071, China.
Institute of Hybrid Materials, College of Material Science and Engineering, Qingdao University, Qingdao 266071, China.
Int J Biol Macromol. 2021 Sep 30;187:594-602. doi: 10.1016/j.ijbiomac.2021.07.149. Epub 2021 Jul 26.
Unlocking the effects of chemical structure and molecular weight of lignin on the properties of carbonized fiber can accelerate the development of lignin-based carbon fiber which was mainly limited by its complex structure. Hardwood kraft lignins (HKLs) with different structures and molecular weights prepared via heat treatment and fractionation processes were spun into ultrafine fibers using electrospinning technique at the assistance of 1 wt% polyoxyethylene (PEO), which was further removed during the carbonization process to eliminate the potential impacts. The structure and molecular weight of HKLs together with their influences on the thermal behavior, fiber morphology, crystal structure and mechanical performance of HKLs ultrafine fibers or carbonized ultrafine fibers were systemically investigated to provide an elaborate knowledge on the relationship between physico-chemical structure and properties of HKLs ultrafine fibers. Results suggest that a high molecular weight of HKL is beneficial to the formation of graphite-like crystallite, and the formed graphite-like crystallite and condensed structure of HKLs are crucial for the improvement of the mechanical performance of carbonized ultrafine fibers.
解析木质素的化学结构和分子量对碳化纤维性能的影响，可以加速木质素基碳纤维的发展，而木质素基碳纤维的发展主要受到其复杂结构的限制。通过热处理和分级过程制备的具有不同结构和分子量的硬木硫酸盐木质素（HKLs），在 1wt%聚氧乙烯（PEO）的辅助下，采用静电纺丝技术纺成超细纤维，在碳化过程中进一步去除，以消除潜在影响。系统研究了 HKLs 的结构和分子量及其对 HKLs 超细纤维或碳化超细纤维热行为、纤维形态、晶体结构和力学性能的影响，为 HKLs 超细纤维的物理化学结构与性能之间的关系提供了详尽的知识。结果表明，HKLs 的高分子量有利于形成类石墨微晶，而形成的类石墨微晶和 HKLs 的凝聚结构对碳化超细纤维力学性能的提高至关重要。
