聚丙烯腈/木质素共混物在熔融纺丝条件下的离子液体流变性能。

Rheology of Polyacrylonitrile/Lignin Blends in Ionic Liquids under Melt Spinning Conditions.

机构信息

Bioproducts, Sciences and Engineering Laboratory, Washington State University, Tri-Cities, 2710, Crimson Way, Richland, WA 99354, USA.

Director of Chemistry and Technology, Wood Protection Technologies, Eco-Building Products, 11568 Sorrento Valley Rd, San Diego, CA 92121, USA.

出版信息

Molecules. 2019 Jul 22;24(14):2650. doi: 10.3390/molecules24142650.

DOI:10.3390/molecules24142650

PMID:31336600

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6680829/

Abstract

Lignin, while economically and environmentally beneficial, has had limited success in use in reinforcing carbon fibers due to harmful chemicals used in biomass pretreatment along with the limited physical interactions between lignin and polyacrylonitrile (PAN) during the spinning process. The focus of this study is to use lignin obtained from chemical-free oxidative biomass pretreatment (WEx) for blending with PAN at melt spinning conditions to produce carbon fiber precursors. In this study, the dynamic rheology of blending PAN with biorefinery lignin obtained from the WEx process is investigated with the addition of 1-butyl-3-methylimidazolium chloride as a plasticizer to address the current barriers of developing PAN/lignin carbon fiber precursors in the melt-spinning process. Lignin was esterified using butyric anhydride to reduce its hydrophilicity and to enhance its interactions with PAN. The studies indicate that butyration of the lignin (BL) increased non-Newtonian behavior and decreased thermo-reversibility of blends. The slope of the Han plot was found to be around 1.47 for PAN at 150 °C and decreased with increasing lignin concentrations as well as temperature. However, these blends were found to have higher elasticity and solution yield stress (47.6 Pa at 20%wt BL and 190 °C) when compared to pure PAN (5.8 Pa at 190 °C). The results from this study are significant for understanding lignin-PAN interactions during melt spinning for lower-cost carbon fibers.

摘要

木质素虽然在经济和环境方面具有优势，但由于生物质原料预处理过程中使用了有害化学物质，以及在纺丝过程中木质素与聚丙烯腈（PAN）之间的物理相互作用有限，因此其在增强碳纤维方面的应用一直受到限制。本研究的重点是使用无化学物质的氧化生物质预处理（WEx）获得的木质素与 PAN 在熔融纺丝条件下进行共混，以生产碳纤维前体。在这项研究中，通过添加 1-丁基-3-甲基咪唑氯盐作为增塑剂，研究了共混 PAN 与从 WEx 工艺中获得的生物炼制木质素的动态流变性能，以解决在熔融纺丝过程中开发 PAN/木质素碳纤维前体的当前障碍。木质素通过丁酐酯化来降低其亲水性并增强其与 PAN 的相互作用。研究表明，木质素的丁酯化（BL）增加了非牛顿行为并降低了共混物的热可逆性。在 150°C 下，PAN 的 Han 图斜率约为 1.47，并随着木质素浓度和温度的增加而降低。然而，与纯 PAN（190°C 时为 5.8 Pa）相比，这些共混物具有更高的弹性和溶液屈服应力（20%wt BL 和 190°C 时为 47.6 Pa）。本研究的结果对于理解熔融纺丝过程中木质素-PAN 相互作用以生产低成本碳纤维具有重要意义。