组分调控协同挤压对稻秸纤维分离及材料性能影响机理分析

Effects of Component Regulation and Synergistic Extrusion on Rice Straw Fiber Separation and Material Properties

摘要:

为探究组分调控协同挤压处理对农作物秸秆纤维分离及材料性能的影响,本研究以水稻秸秆为原料,考察挤压前组分调控对稻秸纤维解构行为的影响,并进一步解析挤压后组分调控对材料性能的作用机制。挤压前组分调控结果表明,与对照组相比,半纤维素的选择性去除促进了纤维细化,平均粒径降低32.0% ,材料抗张指数提升162.3%;木质素的选择性去除有利于高长径比纤维的温和解构,长径比大于20的纤维比例增加65.9% ,平均粒径增加54.9% ,材料抗张指数提升720.8% 。同时去除半纤维素和木质素的样品在挤压过程中结构破坏更加显著,平均粒径较对照组降低45.3% ,材料抗张指数提升306.9%。挤压后组分调控结果表明,半纤维素的去除导致材料孔体积和平均孔径分别增加100.2% 和65.2% ,并降低纤维素链间氢键比例,材料抗张指数较对照组降低48.5%。此外,木质素的回填比例为10%时,经热压处理的纤维材料抗张指数较自然风干组提升24.3%。因此,通过组分调控协同挤压处理可实现纤维的定向解构,并形成“物理纠缠-界面互锁-热塑包裹”的三重交联机制,从而显著提升材料性能。研究结果可为农作物秸秆预处理工艺开发及材料化利用提供依据与支持。

Abstract:

Aiming to investigate the effects of compositional regulation combined with extrusion treatment on the deconstruction of crop straw fibers and the enhancement of material properties, rice straw was used as the raw material. The influence of pre-extrusion compositional regulation on the fiber deconstruction behavior of rice straw was examined and the reinforcing effects of post-extrusion compositional regulation on material performance were further analyzed. Results of pre-extrusion regulation showed that compared with the control group, selective removal of hemicellulose promoted fiber refinement, reducing the average particle size by 32.0% and increasing the tensile index by 162.3%. Selective removal of lignin facilitated mild deconstruction of fibers with high aspect ratios increased the proportion of fibers with aspect ratio greater than 20 by 65.9%, enlarged the average particle size by 54.9%, and enhanced the tensile index by 720.8%. Simultaneous removal of hemicellulose and lignin led to more pronounced structural disruption during extrusion, reducing the average particle size by 45.3% and increasing the tensile index by 306.9%. Results of post-extrusion regulation indicated that hemicellulose removal increased pore volume and average pore size by 100.2% and 65.2%, respectively, while reducing the proportion of hydrogen bonds between cellulose chains, thereby decreasing the tensile index by 48.5% compared with the control. Moreover, when lignin was refilled at a proportion of 10%, the tensile index of hot-pressed fiber materials was increased by 24.3% compared with the air-dried group. Therefore, compositional regulation combined with extrusion treatment enabled directional fiber deconstruction and established a triple cross-linking mechanism of “physical entanglement-interfacial interlocking-thermoplastic encapsulation,” which significantly improved material performance. The findings can provide important experimental evidence and theoretical support for the development of crop straw pretreatment processes and material utilization.