Impact of fibre moisture content on the structure/mechanical properties relationships of PHBV/wheat straw fibres biocomposites
Impact of fibre moisture content on the structure/mechanical properties relationships of PHBV/wheat straw fibres biocomposites
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DOI：
10.1016/j.compscitech.2015.07.015
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发表时间：
2015-09-29
影响因子：
9.1
通讯作者：
Angellier-Coussy, H.
中科院分区：
文献类型：
--
作者：
Berthet, M. -A.;Gontard, N.;Angellier-Coussy, H.
本工作的目的是研究制造过程中纤维水分对PHBV型麦草纤维复合材料结构和最终力学性能之间的关系的影响，重点是界面作用。为此，麦草纤维先在极端相对湿度条件下平衡，然后再用PHBV挤压，达到2wt%W.B.的水分含量。和14.2+/-0.4wt%W.B.相对湿度分别为0和98%。将所得复合材料(纤维含量为20wt%)的结构和力学性能与使用经典干燥的纤维(含水率为3wt%W.B.)填充的材料进行了比较。结果表明，纤维初始含水率对纤维/基质粘合力无明显影响。然而，随着纤维含水率的增加，PHBV的相对分子质量显著降低，这归因于残余水分子引发的水解反应。随着纤维初始水分含量的增加，结晶度的增加与观察到的相对分子质量的降低有关。尽管结构不同，但所有复合材料的拉伸性能都是相似的，从而得出结论：初始纤维含水率不是控制PHBV/麦草纤维复合材料力学性能的主要因素。(C)2015爱思唯尔有限公司。保留所有权利。
The objective of the present work was to investigate the impact of fibre moisture, at the moment of the manufacturing process, on the relationships between the structure of PHBV/wheat straw fibres composites and their final mechanical properties, with a focus on the interphase role. For that purpose, wheat straw fibres were equilibrated at extreme relative humidity conditions before extrusion with PHBV, reaching moisture contents of 2 wt% w.b. and 14.2 +/- 0.4 wt% w.b. at 0 and 98% RH, respectively. The structure and mechanical properties of resulting composites (prepared with a fibre content of 20 wt%) were compared to those of materials filled with fibres classically dried (moisture content of 3 wt% w.b.). It was shown that the fibre/matrix adhesion was visually not affected by the initial fibre moisture content. However, PHBV molecular weight decreased significantly with increasing fibre moisture content, which was attributed to hydrolysis reactions induced by residual water molecules. The increase in crystallinity along with initial fibre moisture content was put in relation to the observed decrease of molecular weight. In spite of structural differences, the tensile properties were similar for all composites, leading to the conclusion that the initial fibre moisture content was not a predominant factor for controlling the mechanical properties of PHBV/wheat straw fibres composites. (C) 2015 Elsevier Ltd. All rights reserved.