High‐performance hierarchical composites based on polyamide 6, carbon fiber and graphene oxide

• Published in: Polymer composites Vol. 44; no. 6; pp. 3387 - 3400
• Main Authors: Damacena, Luiz Henrique Cavalcante, Ferreira, Eder Henrique Coelho, Ribeiro, Hélio, Fechine, Guilhermino José Macedo, Souza, Adriana Martinelli Catelli
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-06-2023; Blackwell Publishing Ltd
• Subjects: Carbon fiber reinforced plastics; carbon fiber reinforced polyamide 6; Carbon fibers; Composite materials; Coupling agents; Crystal growth; Extrusion molding; Fatigue life; Fatigue tests; Flexural strength; Graphene; graphene oxide; hierarchical composites; Impact strength; Injection molding; interfacial properties; mechanical properties; Modulus of elasticity; Modulus of rupture in bending; Morphology; Photomicrographs; Polyamide resins; Tensile strength; Thermodynamic properties
• ISSN: 0272-8397; 1548-0569
• DOI: 10.1002/pc.27328

This study reports the effect of graphene oxide (GO) coating on carbon fiber (CF) surface on the mechanical and thermal properties and morphology of CF‐reinforced polyamide 6 (PA6) composites containing 7.5 wt% of short CFs. GO was coated on the CF surface by a physical absorption method with concentrations ranging from 0.05 to 0.5 wt% GO. The PA6/CF composites were prepared by extrusion, and the specimens were obtained by injection molding. Their morphology (SEM, XRD tests), mechanical (tensile, flexural, impact, and fatigue tests), and thermal properties (DSC, TG and HDT tests) were analyzed. A significant change in the preferential (growth) crystal planes of PA6 was observed upon the incorporation of CFs containing GO, favoring the formation of α crystals in PA6. GO coating on CFs was effective and provided an increase in tensile strength and Young's modulus up to 12% and 24%, flexural strength and flexural modulus up to 22% and 25%, and a decrease in impact strength and fatigue life up to 30% and 23%, respectively, when compared to unmodified PA6/CF composites. Fracture micrographs indicated an increase in the PA6/CF interaction and the effectiveness of GO as a coupling agent for the composite.