Abstract Replacing glass fibres with flax fibres is a first step in reducing the ecological impact of thermoset composite materials, and employing a biodegradable thermoplastic matrix opens up recycling and composting as end-of-life routes. Here, a range of flax fibre reinforced biodegradable thermoplastics were investigated: poly-(hydroxy alkanoate) (PHA), poly-(butylene-succinate) (PBS) and poly-(lactide) (PLA). Poly-(propylene) (PP) and maleic-anhydride grafted poly-(propylene) (MAPP) were studied as industry benchmarks. This study systematically examines the interface between flax fibres and these matrices at multiple scales, and explores the correlations between the measured interfacial properties and macro-scale composite properties. Micro-droplet tests reveal that the adhesion of flax with biodegradable polymers is at least similar to flax-MAPP, and better than flax-PP. In-plane [±45]s shear tests and tensile tests on unidirectional composites reaffirm the observations at the micro-scale, that biodegradable polymer/flax composites present mechanical properties comparable to or better than MAPP/flax composites. Furthermore, comparison between interfacial and composite tensile properties reveals that fibre-matrix adhesion has a substantial role in biocomposite performance.

中文翻译：

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可生物降解聚合物-亚麻纤维复合材料的界面和力学表征

摘要 用亚麻纤维代替玻璃纤维是减少热固性复合材料对生态影响的第一步，采用可生物降解的热塑性基质开辟了回收和堆肥作为报废途径。在这里，研究了一系列亚麻纤维增强的可生物降解热塑性塑料：聚（羟基链烷酸酯）（PHA）、聚（丁二酸丁二醇酯）（PBS）和聚（丙交酯）（PLA）。聚（丙烯）（PP）和马来酸酐接枝的聚（丙烯）（MAPP）作为行业基准进行了研究。本研究在多个尺度上系统地检查了亚麻纤维与这些基质之间的界面，并探讨了测量的界面特性与宏观复合材料特性之间的相关性。微滴测试表明，亚麻与可生物降解聚合物的附着力至少与亚麻-MAPP 相似，并且优于亚麻-PP。单向复合材料的面内 [±45]s 剪切试验和拉伸试验再次证实了微观尺度上的观察结果，即可生物降解的聚合物/亚麻复合材料的机械性能与 MAPP/亚麻复合材料相当或更好。此外，界面和复合材料拉伸性能之间的比较表明，纤维-基质粘附在生物复合材料性能中具有重要作用。