Abstract

In this work, the defibrillation of cellulose fibers (CF) in the presence of hydroxyethyl cellulose (HEC) within the one-step twin-screw extrusion (TSE) process was examined. The effect of the TSE on cellulose fiber size reduction as well as CF-HEC biocomposites properties were investigated. The results showed that the TSE of cellulose fiber-hydroxyethyl cellulose (CF-HEC) with different cellulose fiber contents (50, 65, and 80 wt%) resulted in partial defibrillation of the cellulose fibers. The fractionation test of the cellulose fibers confirmed that their size was reduced and some fibrillation was observed in microscopy studies. The maximum width reduction of 46% occurred with 80 wt% cellulose content. However, the partial width reduction was also observed with 50% and 65 wt% of cellulose contents. Based on rheological measurements, the shear-viscosity trend of CF-HEC dispersion abruptly dropped when higher fiber content (80 wt%) was extruded, which was related to the fibrillation of the cellulose fibers as well as the reduction of the length. The extruded CF-HEC materials (powder form) were compression molded to prepare the biocomposites with different cellulose fiber contents (50, 65, and 80 wt%). The extruded CF-HEC powders were diluted with addition extra HEC to make biocomposites with lower fiber content (20%, 30%, and 40 wt%) and compression molded to study how the size reduction of the cellulose fibers affected the mechanical properties of biocomposites. The results showed that the E-modulus improved from 0.4 GPa of the neat HEC to 1.6 GPa for the composite with 40 wt% CF. Interestingly, the tensile strength of CF-HEC biocomposite with 40 wt% confirmed a clear improvement from 9.8 to 26.6 MPa, confirming good interaction between HEC and CF.

Graphic abstract

Preparation (mixing, TSE, and hot-pressing) and characterization (FE-SEM, rheometry, and tensile test) of CF-HEC biocomposite

中文翻译：

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纤维素纤维和羟乙基纤维素的一步式双螺杆挤出工艺生产原纤化纤维素生物复合材料

摘要

在这项工作中，研究了在一步式双螺杆挤出（TSE）过程中在羟乙基纤维素（HEC）存在下纤维素纤维（CF）的除纤颤作用。研究了TSE对降低纤维素纤维尺寸以及CF-HEC生物复合材料性能的影响。结果表明，具有不同纤维素纤维含量（50、65和80 wt％）的纤维素纤维-羟乙基纤维素（CF-HEC）的TSE导致纤维素纤维部分除颤。纤维素纤维的分级测试证实其尺寸减小，并且在显微镜研究中观察到一些原纤化。当纤维素含量为80 wt％时，最大宽度减少量为46％。然而，当纤维素含量为50重量％和65重量％时，也观察到部分宽度减小。根据流变学测量，当挤出更高含量的纤维（80 wt％）时，CF-HEC分散体的剪切粘度趋势突然下降，这与纤维素纤维的原纤化以及长度的减少有关。将挤出的CF-HEC材料（粉末形式）压缩成型以制备具有不同纤维素纤维含量（50、65和80 wt％）的生物复合材料。将挤出的CF-HEC粉末与额外的HEC稀释，以制成纤维含量较低（20％，30％和40 wt％）的生物复合材料，并压制成型，以研究纤维素纤维的尺寸减小如何影响生物复合材料的机械性能。结果表明，对于含40 wt％CF的复合材料，E模量从纯HEC的0.4 GPa提高到1.6 GPa。有趣的是

图形摘要

CF-HEC生物复合材料的制备（混合，TSE和热压）和表征（FE-SEM，流变学和拉伸试验）