Establishment of "Rigid-Flexible" Transition Interface between Carbon Fiber and Resin Matrix for Interfacial Adhesion...

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Interfacial adhesion is crucial for composite material performance.
• Carbon fibers (CFs) often exhibit weak bonding with polymer matrices.
• Developing effective interface structures is key to enhancing composite properties.

Purpose of the Study:

• To establish a
• rigid-flexible
• transition interface structure between carbon fibers (CFs) and resin matrix.
• To improve interfacial adhesion and mechanical properties of CF-reinforced composites.
• To investigate the surface characteristics and interfacial behavior of functionalized CFs.

Main Methods:

• Surface functionalization of CFs using polydopamine/polyethylenimine (PEI) codeposition.
• Chemical grafting of flexible polyurethane (PU) and branched PEI polymers onto CF surfaces.
• Characterization of surface properties (active groups, roughness, surface energy) and interfacial adhesion (interfacial shear strength, interlaminar shear strength).

Main Results:

• Functionalization introduced abundant active groups (-NH2, -NH) and increased surface roughness and energy.
• Interfacial shear strength increased by 49.4% and interlaminar shear strength by 43.2%.
• Flexural strength improved by 35.5% and flexural modulus by 45.9% due to the flexible PU interface.

Conclusions:

• The developed
• rigid-flexible
• interface effectively enhances interfacial adhesion between CFs and the resin matrix.
• The flexible PU layer acts as a tear-resistant component, promoting uniform stress transfer.
• This strategy significantly improves the overall mechanical performance of carbon fiber-reinforced polymer composites.