Investigation of morphologies and tensile impact toughness of immiscible polyphenylene sulfide/polyether sulfone films and carbon fiber composites by quantitative optical methods

Targeting the transfer and improvement of impact toughness in composites deriving from polymer mixtures, we investigated the effectiveness of immiscible polyphenylene sulfide (PPS)/polyether sulfone (PES) blends reinforced by endless carbon fibers. Tensile impact testing of films and composites was performed. Impact strengths of films showed high dependency of the PPS crystallinity and crystal orientation influenced by the present amount of PES. Intermolecular interactions between the immiscible phases and the presence of amorphous areas were assumed to be the driving factor for the load transfer in these films. Optical evaluation of local and global strain at break of films revealed a significant increase in plasticization. Tensile impact tested ±45° carbon composites exhibited high improvements of toughness and deformation ability provided by the PES spheres. The quantification of morphologies evidenced a strong correlation of PES profile's mean diameters and next neighbor distances with impact toughness and deformation ability, qualifying these novel materials as potential alternatives for conventional high‐end composites. POLYM. COMPOS., 40:3725–3736, 2019. © 2019 Society of Plastics Engineers