Nano-modified epoxy: the effect of GO-based complex structures on mechanical performance

Area of Science:

• Materials Science and Engineering
• Polymer Chemistry
• Nanotechnology

Background:

• Nanofillers (NFs) in polymer systems influence structure, especially in partially miscible blends like polymer-modified epoxy.
• Graphene oxide (GO) and amine-terminated butadiene-acrylonitrile copolymer (ATBN) are key components for modifying epoxy properties.

Purpose of the Study:

• To investigate the structure-directing effects of GO and ATBN in rubber-modified epoxy systems.
• To explore the impact of grafting methods (in situ vs. pre-made) and GO functionalization on epoxy composite performance.

Main Methods:

• Utilized different combinations of graphene oxide (GO) and amine-terminated butadiene-acrylonitrile copolymer (ATBN) in epoxy matrices.
• Employed both in situ and pre-made grafting techniques for GO-ATBN functionalization.
• Investigated GO grafted via epoxy groups or edge-localized carboxyls.

Main Results:

• Grafted ATBN chains induced GO-g-ATBN to form nacre-mimicking lamellar structures, unlike typical exfoliation.
• These lamellar structures, with elastically embedded GO, resulted in superior mechanical performance.
• A small concentration of grafted polymer provided greater benefits than a higher concentration of separately added ATBN.

Conclusions:

• Grafting polymers onto GO significantly alters self-assembly into beneficial nacre-mimicking structures.
• The degree of grafted chains and the geometry of self-assembled arrays are crucial for enhanced mechanical properties.
• This approach demonstrates a highly effective strategy for improving epoxy composite performance.