Studies on using biomaterials hybridized with other materials to produce biomaterials have been paid more attention due to their low cost, abundance, renewability, and degradability. Therefore, these materials are ecofriendly and nontoxic to humans. A large number of used coffee grounds (SCGs) are often discarded and replacements are necessary for dealing with environmental problems. This work developed sustainable materials by reusing SCGs. Used coffee grounds were mixed with epoxy resin at different amounts: 30 wt %, 40 wt %, 50 wt %, and 60 wt %. SCGs were treated with 0.5 N NaOH, at SCGs/NaOH ratio of 1 : 2. SEM images showed that the material with 30 wt % SCGs has good compatibility without phase division on the SCGs-epoxy interface. Results of mechanical properties of epoxy composites with 30 wt % SCGs are as follows: tensile strength of 44.81 ± 10 MPa, flexural strength of 80.07 ± 0.16 MPa, compressive strength of 112.56 ± 0.11 MPa, and Izod strength and impact of 8.21 ± 0.19 kJ/m². In terms of flame-retardant properties, the oxygen index is limited to 20.8% ± 0.20 and the burning rate according to UL94HB is 27.02 ± 0.29 mm/min. The obtained results indicate that it is possible to produce biohybrid composites from epoxy resin and SCGs. This work offers an ecofriendly alternative method to use the waste of the coffee industry. It contributes to improvements of the general characteristics of composites such as mechanical, thermal, and flame-retardant properties. This work proved that SCGs have a high potential to be used in a wide range of composite materials for civil engineering applications.

中文翻译：

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基于旧咖啡渣和环氧树脂的混合生物复合材料：机械性能和耐火性

利用生物材料与其他材料杂交生产生物材料的研究因其低成本、丰富性、可再生性和可降解性而受到越来越多的关注。因此，这些材料对人类无害且环保。大量使用过的咖啡渣 (SCG) 经常被丢弃，为了解决环境问题需要更换。这项工作通过重复使用 SCG 开发了可持续材料。用过的咖啡渣以不同的量与环氧树脂混合：30wt%、40wt%、50wt%和60wt%。SCG 用 0.5 N NaOH 处理，SCG/NaOH 的比例为 1:2。SEM 图像表明，含有 30 wt% SCG 的材料具有良好的相容性，在 SCG-环氧树脂界面上没有相分离。含 30 wt% SCG 的环氧复合材料的机械性能结果如下：拉伸强度为 44。² . 在阻燃性能方面，氧指数限制在 20.8%±0.20，燃烧速率根据 UL94HB 为 27.02±0.29 mm/min。所得结果表明，可以用环氧树脂和 SCG 制备生物杂化复合材料。这项工作提供了一种使用咖啡工业废料的环保替代方法。它有助于改善复合材料的一般特性，如机械、热和阻燃性能。这项工作证明 SCG 具有用于土木工程应用的各种复合材料的巨大潜力。