A Novel Preparation of Ribbon‐Shaped PAN Precursor From Film With Structural and Property Analysis

ABSTRACT The rapid adoption of carbon fiber in industrial applications has increased demand for materials that combine high performance with low cost, thereby intensifying pressure on carbon‐fiber manufacturing processes. Conventional circular polyacrylonitrile (PAN) precursors mostly rely on finer denier to improve mechanical properties; however, this strategy lowers precursor yield and diminishes cost‐effectiveness. This study proposed an innovative method utilizing PAN films to prepare ribbon‐shaped PAN precursors. High‐quality PAN films were subjected to hot‐water washing, strip cutting, and hot stretching to obtain ribbon‐shaped precursors. The resulting ribbon‐shaped precursors, 8.0 μm thick and 2.4 mm wide, exhibited clear geometric advantages, consisting of two‐dimensional, plate‐like microfibrils stacked in layered assemblies. Microstructural analysis revealed uniform density without voids or significant skin‐core defects. Their orientation, crystallinity, tensile strength, and thermodynamic properties were comparable to those of conventional circular precursors, laying the foundation for producing high‐performance ribbon‐shaped carbon fibers. This work pioneers a new pathway for developing PAN‐based carbon fibers that combine high strength with high production efficiency.