Deveopment and Characterisation of Continuous Carbon Fiber Reinforced Epoxy Composites

ABSTRACT
Epoxy composites, in their pure form, generally lack strength, but this limitation can be overcome by integrating carbon fibre, a resource often discarded after fruit harvesting. The addition of carbon fibre, a sustainable and eco-friendly material, offers considerable potential to enhance the strength and resilience of the resulting composite. Carbon fibre serves as a renewable alternative to fossil fuel-based products. An experimental study was conducted to investigate the potential of reinforcing epoxy with carbon fibre for high-strength applications. The research aimed to evaluate the mechanical, thermal, and microstructural properties of carbon fibre-reinforced epoxy composites, utilizing primary materials such as carbon fibre, a mold, and a digital balance. Continuous carbon fibre with a thickness of 3 ± 0.2 mm was selected, and a hand lay-up method was employed with varying carbon fibre volume percentages from 0 to 20%, using 0% carbon fibre as a control. The epoxy was mixed with the hardener in a 2:1 ratio before adding the reinforcement. After allowing the mold to set for 24 hours, specimens were cut for testing. The investigation assessed mechanical properties, including tensile strength, impact strength, and hardness, as well as thermal and microstructural characteristics. The results showed that the epoxy composite reinforced with 20 vol.% carbon fibre outperformed the control and other carbon fibre-reinforced composites in terms of mechanical properties. The addition of carbon fibre increased hardness, reaching a maximum value of 55 BHN for epoxy+20 vol.% carbon fibre. Impact strength also increased, peaking at 20 vol.% carbon fibre (5.1 J). Thermal stability, assessed via TGA, revealed that 20 vol.% carbon fibre had the highest mass residue of 15.0%, indicating greater stability at elevated temperatures. Furthermore, the epoxy+20 vol.% carbon fibre composite displayed a well-distributed fibre arrangement with minimal agglomeration and voids. In conclusion, the epoxy composite reinforced with 20 vol.% carbon fibre demonstrated significant enhancements in hardness, tensile and impact strength, thermal stability, and microstructural characteristics compared to the control and other composite samples.
Keywords: polymer composites, Carbon fibre, mechanical properties, Thermal properties, microstructural characteristics