Influence of epoxy methyl ricinoleate on mechanical, visco‐elastic, and low‐velocity impact properties of flax fiber reinforced epoxy composite

Abstract Due to the decline in petroleum‐derived resources and growing environmental awareness, scientists are seeking bio‐based alternatives for synthetic fibers and resins in composites. This study examines the effect of partially substituting epoxy components with castor oil‐based bio‐resins. The goal is to develop environmentally sustainable materials while maintaining performance. Epoxy methyl ricinoleate (EMR) was synthesized and assessed as a supplementary component in an epoxy copolymer cured with Triethylenetetramine. Flax fabric was used as reinforcement in epoxy and epoxy–EMR copolymer matrices to create eco‐friendly bio‐composites. The epoxy matrix was modified with 10%, 20%, and 30% EMR and combined with bidirectional flax fabric to balance toughness and stiffness. Tensile strength increased by 6.5% in EPEMR/20‐C. Impact strength improved by 19% in EPEMR/30‐C compared to the neat epoxy composite. EMR incorporation, especially up to 20%, enhanced ILSS by about 13%. Fatigue performance improved by 43% due to increased matrix toughness and better interfacial bonding. Low‐velocity impact tests were performed at 10 and 20 J to study perforation and non‐perforation scenarios. The composite with 20% EMR showed the highest impact resistance. This highlights its potential for structural components with reduced weight and improved interfacial bonding. EMR‐modified bio‐composites were eco‐friendly and exhibited enhanced mechanical properties. These findings suggest their suitability for structural and automotive applications. Highlights The effects of EMR bio‐resin on epoxy composites are analyzed. High bio‐content composites, comprising approximately 50 wt%, are developed. EMR improved bio‐composites' fatigue by 43% via tougher matrix and bonding. Optimal EMR addition enhances composite laminates' impact resistance in LVI tests. Toughness and bio‐content were enhanced by adding EMR.