Enhanced interfacial properties of carbon fibers reinforced epoxy or PP composites using modified graphene oxide with two different polymer brushes

Carbon fibers (CFs) can usually only be used to reinforce polar (or non-polar) resins, and if they are to be used for reinforcing with another polymer type, they need to be surface-modified, which will inevitably damage the surface of the carbon fibers and thus reduces the overall performance of the composite. In this work, graphene oxide was first prepared and modified, and then two polymer brushes, polystyrene (PS) and hydroxypropyl polyacrylate (PHPA) were grafted onto its surface in a one-step process. This approach reduced the damage caused to the CFs surface by multiple treatments and improved the interfacial adhesion between CFs and different resin matrices. An electrophoretic deposition method was used to deposit the modified GO on the surface of CFs, which can form strong interaction between CFs and a variety of resins. The results showed that different molecular chains have been grafted on the surface of GO, and then the latter was uniformly deposited on the surface of CFs, improving their surface toughness. Additionally, when the suspension concentration was only 1 mg/mL, the interfacial shear strength (IFSS) of CF/epoxy and CF/PP increased by 52.0% and 26.5%, respectively. This means that a small amount of GO can significantly improve the interfacial properties of carbon fiber reinforced composites (CFRCs). Therefore, they can be applied to aerospace, wind energy and other industries to effectively improve the interfacial bonding between fiber and resin, after surface modification.

Graphical abstract