Polymer composites have been extensively used for the last 30 years in the automotive, green-energy, maritime and aerospace industries. While the demands of composites' applications are increasing, complications are arising regarding their sustainability. In this work, a siloxane-based vitrimer with fast stress-relaxation, and its Glass-Fibre-Reinforced Vitrimer (GFRV) were manufactured and mechanically characterised as a sustainable alternative to thermoset composites produced by infusion. Dynamic mechanical analysis and differential scanning calorimetry were performed to identify the ageing effect on the glass-transition temperature of the materials. Tensile and in-plane shear tests were executed to investigate the materials’ performance at elevated temperature. The results were compared to the ones of a thermoset benchmark and showed that after ageing and up to 50 °C, both the neat vitrimer and its corresponding composite exhibited a thermomechanical performance comparable to their thermoset counterparts. GFRV specimens were then successfully reprocessed by hot-pressing up to two consecutive cycles. The GFRV specimen was thermoformed into an omega-stiffener profile by the first hot-pressing cycle, while its flat profile was restored during the second cycle. Finally, the reprocessing results were evaluated by optical microscopy, demonstrating that the newly developed advanced GFRV is indeed a viable, sustainable alternative.

中文翻译：

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可再加工、硅氧烷基玻璃纤维增​​强玻璃体的热机械表征

过去 30 年来，聚合物复合材料已广泛应用于汽车、绿色能源、海事和航空航天工业。虽然复合材料的应用需求不断增加，但其可持续性也出现了复杂化。在这项工作中，制造了一种具有快速应力松弛的基于硅氧烷的 vitrimer 及其玻璃纤维增​​强 Vitrimer (GFRV)，并进行了机械表征，作为通过灌注生产的热固性复合材料的可持续替代品。通过动态力学分析和差示扫描量热法来确定老化对材料玻璃化转变温度的影响。进行拉伸和面内剪切测试以研究材料在高温下的性能。将结果与热固性基准的结果进行比较，结果表明，在老化和高达 50°C 的温度后，纯玻璃体及其相应的复合材料都表现出与热固性材料相当的热机械性能。然后通过热压连续两个循环成功地对 GFRV 样本进行了再处理。GFRV 样本通过第一个热压循环热成型为 omega-加强筋轮廓，而其平坦轮廓在第二个循环中恢复。最后，通过光学显微镜对后处理结果进行了评估，证明新开发的先进 GFRV 确实是一种可行、可持续的替代方案。