Investigating the use of natural hollow fibers from common milkweed to improve the mechanical and thermal properties of epoxy resin

Abstract Milkweed floss was used as a reinforcement to develop lightweight epoxy composites with enhanced thermal insulating properties. Seed fibers from Asclepias Syriaca harvested in Quebec were used for this study. Some fibers were treated with acetone to remove their protective hydrophobic coating. Epoxy resin was blended with 15% w/w of native or acetone‐treated milkweed floss to form prepregs. The prepregs were casted into molds, degassed, and compressed to produce the composites. The composites were passed through a post‐curing phase before characterization. The composites and the epoxy resin alone were characterized to determine their density, porosity, thermal conductivity, thermal degradation, mechanical resistance, and thermo‐mechanical behavior. The composites reinforced with native or acetone‐treated milkweed floss were 7.4% and 10.3% lighter than the epoxy resin, respectively. The specific elastic modulus of the resin increased by 9.6% and 20.1% with the addition of native or acetone‐treated fibers, respectively. The thermal conductivity of the epoxi decreased by 7.8% and 15.6% with the use of native or acetone‐treated milkweed floss, respectively. Due to their low weight and reduced thermal conductivity, the milkweed‐reinforced epoxy composites may find applications in the production of structural and insulating elements for vehicles and buildings.