Evaluation of Mechanical and Water Absorption Behavior of Natural Fiber-Reinforced Hybrid Biocomposites

The virtues of hybrid composites are higher performances and improved mechanical properties as compared to polymer composites. Hence, it have been extensively used in various applications. However, only a few works reported on the performance of natural fiber-reinforced biocomposite. In this study, the experimental work has been carried out to investigate the mechanical properties, such as tensile, flexural and impact, of randomly orientedCalotropis giganteaFiber (CGFs) & Palmyra fiber (PFs)-reinforced Phenol-Formaldehyde (PF) hybrid biocomposites. The samples have been prepared by varying the fiber percentages and fiber length by using hand layup method. The fabricated specimens were tested as per ASTM standard. The results illustrate that the addition of palmyra fiber withCalotropis giganteafiber composites improved the mechanical properties of hybrid composite. Hybridization ofCalotropis giganteaFiber (CGFs) & Palmyra fiber (PFs) was effective at higher fiber volume percentage composites. Variation in fiber length shows effective results in mechanical properties. The water absorption of the composites increased with the increase in the fiber volume percentage, all the composites attained equilibrium state after 120 hours. To understand the failure mechanism of composites during mechanical testing, the failed specimens were examined using Scanning Electron Microscopic (SEM) images. Also, the failure modes and their effects were discussed.

Automated summary

Hybrid composites offer higher performances and improved mechanical properties compared to polymer composites. This study investigated the mechanical properties of Phenol-Formaldehyde (PF) hybrid biocomposites reinforced with randomly oriented Calotropis gigantea Fiber (CGFs) and Palmyra fiber (PFs), including tensile, flexural, and impact properties. The results showed that adding Palmyra fiber improved the mechanical properties of the hybrid composite, especially at higher fiber volume percentages. Variation in fiber length also had a significant effect on the mechanical properties. Additionally, the water absorption of the composites increased with the increase in fiber volume percentage, reaching equilibrium after 120 hours. Scanning Electron Microscopic (SEM) images were used to examine the failure mechanism of the composites during mechanical testing.