Accelerated weathering studies of kenaf/sisal fiber fabric reinforced fully biobased hybrid bioepoxy composites for semi-structural applications: Morphology, thermo-mechanical, water absorption behavior and surface hydrophobicity

The reduction of the environmental impact from renewable resources can provide an interesting sustainable platform. Natural fiber is an outstanding renewable resource for making composite materials for lightweight applications. However, the major disadvantage of natural fiber as reinforcement material in composites is their hydrophilic nature. The present investigation is an attempt to develop kenaf/sisal fiber fabric reinforced bioepoxy hybrid composites and assess the performance of the composites under accelerated weathering conditions. To the best of our knowledge as of now there is no work has been published in this concept. The bioepoxy resin and kenaf/sisal fiber fabrics were used for making hybrid bio-based composites and manufactured composite laminates using a compression molding method. For comparison purpose, a neat bioepoxy thermoset was fabricated by casting mold technique. To promote the accelerated weathering of composites, the samples were exposed to environmental conditions such as ultraviolet radiation, extreme temperature and humidity conditions in accelerated weathering tester machine according to ASTM C155-13 cycle 1. The tensile, impact, morphology, thermogravimetric analysis, dynamic mechanical analysis, and water absorption test were performed for both before and after weathering test samples according to international standards. The results indicated that the manufactured fully bio-based kenaf/sisal fiber reinforced hybrid bioepoxy composites showed moderate properties when compared to the neat bioepoxy composite at both before and after weathering conditions. From the results, it is worth to point out that these fully bio-based composites are promising composite material for semi-structural applications. (C) 2019 Elsevier Ltd. All rights reserved.