Advanced manufacturing and applications of lignin based fibrous materials

木质素是地球上第二丰富的生物聚合物，具有作为低成本和可再生的使能材料用于各种增值应用的潜力。在众多正在研究的木质素应用中，木质素基碳纤维（微米级LCF）是最有前途的产品之一。自20世纪60年代以来，木质素一直在研究其作为碳纤维（CF）前体的潜力。从那时起，已经报道了利用不同类型的木质素和木质素/聚合物共混物（例如木质素/聚丙烯腈（PAN））的干法、湿法或熔融纺丝的各种系统。根据树种（软木、硬木或一年生纤维）、分离方法（硫酸盐法、亚硫酸盐法、苏打法或其他生物精炼工艺）和纤维加工技术（湿/干/熔纺、氧化、稳定化、碳化等），已经生产了各种木质素基前体和CF。然而，这些微米级纤维不能满足汽车结构应用的性能/成本要求。通过结合纳米纤维和木质素的优点，据信可以开发出一类新的低成本混合碳纤维和纤维组件，用于结构应用如汽车复合材料和功能应用如电磁屏蔽。在这个项目中，我们建议研究的可行性生产碳纳米纤维（CNF）从木质素，木质素/聚合物共混物，和他们的木质素/纳米粒子增强的静电纺丝过程。为了解决生产经济性的问题，将探索高通量纺丝系统，如无针静电纺丝和熔喷技术。木质素基碳纳米纤维（LCNFs）的形态，机械，电气和电磁性能的特点和各种应用的潜力将被评估。为了评估结构复合材料的性能并探索新的机会，将制造3D打印的木质素基复合材料试样。该计划的结果将证明木质素基复合CNFs作为可扩展纺丝工艺制造的独特工程材料的潜力。因此，它将为丰富的可再生天然聚合物木质素增值建立一条途径。最重要的成果是在多学科环境中培养了一批高素质的本科生，研究生（硕士，博士）和博士后（PDF）。

Lignin, the second most abundant biopolymer on earth, has the potential to serve as a low cost and renewable enabling material for a wide variety of value added applications. Of the numerous lignin applications under investigation, lignin-based carbon fibre (micron level LCFs) is one of the most promising products. Lignin has been under investigation for its potential as a carbon fibre (CF) precursor since the 1960's. Since that time a variety of systems have been reported utilizing dry, wet, or melt spinning of different types of lignin and lignin/polymer blends, such as lignin/polyacrylonitrile (PAN). Depending on the species (softwood, hardwood or annual fibre), method of isolation (Kraft, sulphite, soda or other biorefinery process), and fibre processing technology (wet/dry/melt spinning, oxidation, stabilization, carbonization, etc.) various lignin-based precursors and CFs have been produced. However these micron level fibres fail to meet the performance/cost requirements for automotive structural applications. By combining the advantages of nanofibres and lignin it is believed that a new class of low cost hybrid carbon fibre and fibrous assemblies can be developed for both structural applications such as automobiles composites and functional applications such as electromagnetic shields. In this program we propose to study the feasibility of producing carbon nanofibre (CNF) from lignin, lignin/polymer blends, and their lignin/nanoparticle reinforcements by the electrospinning process. In order to address the issues of production economy high throughput spinning systems such as needleless electrospinning and melt-blown technology will be explored. The morphological, mechanical, electrical, and electromagnetic properties of the lignin-based carbon nanofibres (LCNFs) will be characterized and their potential for various applications will be assessed. To assess the structural composite performance and to explore new opportunities, the 3D printed lignin based composite test specimen will be fabricated. The outcome of this program will demonstrate the potential of lignin-based composite CNFs as a unique engineering material manufactured by scalable spinning process. As a result, it will establish a pathway for adding value to the abundantly available, renewable natural polymer, lignin. The most important outcome is the training of a team of highly qualifies personnels (HQPs) at the undergraduate, graduate (MASc, PhD) and Post doctoral (PDF) level in a multidisiplinary environment.