The application of natural flax fibre/epoxy composites is growing in the automotive sector due to their good stiffness and damping properties. However, the impact damage resistance of flax/epoxy composites is limited due to the brittle nature of both epoxy and flax fibres and strong fibre/matrix adhesion. Here, biobased thermoplastic cellulose acetate (CA) is deployed as a fibre treatment to alter the damage development of flax/epoxy composites subjected to low-velocity impact. The perforation threshold energy and the perforation energy of unmodified cross-ply composites increased respectively by 66% and 42% with CA-treated flax fibres. The CA-modification modestly decreased the transverse tensile strength and in-plane tensile shear strength of the composites. However, it altered the brittle nature of flax/epoxy laminates in quasi-static tests into ductile failure with clearly increased fibre–matrix debonding.

天然亚麻纤维/环氧树脂复合材料由于其良好的刚度和阻尼性能，在汽车领域的应用正在增长。然而，由于环氧树脂和亚麻纤维的脆性以及纤维/基体的强粘合性，亚麻/环氧树脂复合材料的抗冲击损伤能力受到限制。在这里，生物基热塑性醋酸纤维素 (CA) 被用作纤维处理，以改变亚麻/环氧树脂复合材料在低速冲击下的损伤发展。使用 CA 处理的亚麻纤维，未改性的交叉层复合材料的穿孔阈能和穿孔能量分别增加了 66% 和 42%。CA 改性适度降低了复合材料的横向拉伸强度和面内拉伸剪切强度。然而，