Hemp core is a lignocellulosic residue in the production chain of hemp strands. Huge amounts of hemp core are gathered annually in Europe (43,000 tons) with no major application end. Such lignocellulosic wastes have potential as filling or reinforcing material to replace synthetic fibers and wood fibers in polymer composites. In this study, hemp core biomass was treated under different NaOH concentrations and then defibrated by means of Sprout Waldron equipment to obtain single fibers. Polypropylene matrix was reinforced up to 50 wt.% and the resulting hemp core fibers and the flexural properties were investigated. The results show that the flexural strength of composites increased with the intensity of NaOH treatment. The effect of NaOH was attributed to the removal of extractives and lignin in the fiber cell wall leading to improved interfacial adhesion characteristics. Besides, a methodology was established for the estimation of the intrinsic flexural strength of hemp core fibers. The intrinsic flexural strength of hemp core fibers was calculated to be 940 MPa for fibers treated at 10 wt.% of NaOH. In addition, a relationship between the lignin content and the intrinsic strength of the fibers was established.

中文翻译：

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大麻芯残留物的增值：NaOH处理对PP复合材料的弯曲强度和大麻芯纤维的固有弯曲强度的影响。

大麻芯是大麻链生产链中的木质纤维素残基。欧洲每年收集大量大麻芯（43,000吨），而没有主要用途终止。这种木质纤维素废料具有作为填充或增强材料的潜力，以代替聚合物复合材料中的合成纤维和木纤维。在这项研究中，大麻核心生物质在不同的NaOH浓度下进行处理，然后通过Sprout Waldron设备进行解纤以获得单纤维。聚丙烯基体被增强至50％（重量），并研究了所得的麻芯纤维和挠曲性能。结果表明，复合材料的弯曲强度随NaOH处理强度的增加而增加。NaOH的作用归因于纤维细胞壁中提取物和木质素的去除，从而改善了界面粘附特性。此外，建立了一种估算大麻芯纤维固有抗弯强度的方法。对于用10重量％的NaOH处理的纤维，大麻芯纤维的固有弯曲强度经计算为940MPa。另外，建立了木质素含量与纤维的固有强度之间的关系。