Comparison of two kinds of liquid crystalline monomers with different mesogenic units grafted graphene oxide on thermal and mechanical properties of epoxy nanocomposite materials

ABSTRACT

Two kinds of liquid crystalline monomers with different mesogenic units grafted graphene oxide (M2-g-GO and M4-g-GO) were successfully synthesised to enhance thermal and mechanical properties of nanocomposites, owing to the improvement of dispersion and interface interaction between the fillers (M2-g-GO and M4-g-GO) and the epoxy matrix (DGEBA, E-51). And the structures and comprehensive properties of M2-g-GO, M4-g-GO, and their nanocomposites were analysed using FTIR, SEM, XRD, Raman, DSC, TGA, and POM tests. Compared with the neat epoxy and 3 wt% GO/epoxy composites, thermal properties of M2-g-GO/epoxy and M4-g-GO/epoxy nanocomposites were obviously improved, meanwhile, mechanical property measures prove M2-g-GO/epoxy and M4-g-GO/epoxy nanocomposites that exhibit higher impact strength, flexural strength and modulus. For example, the T_d5% of epoxy nanocomposites with 1, 2, 3, and 4 wt% M2-g-GO were around 385°C, which was about 15°C larger than that of the neat epoxy. The T_d5% of epoxy nanocomposites with 2 and 3 wt% M4-g-GO were 383°C and 388°C, respectively, which was about 13°C and 18°C larger than that of the neat epoxy. In a word, the M2-g-GO and M4-g-GO as fillers exhibit underlying feasibility to improve thermal and mechanical properties of nanocomposites.

Graphical abstract

KEYWORDS:

• Liquid crystalline monomers
• Schiff base
• biphenyl base
• graphene oxide
• thermal and mechanical properties

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

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Additional information

Funding

This work was supported by the National Natural Science Foundation of China (No. U1708258).