Abstract. Graphene oxide (GO) sheets were chemically grafted with thermotropic liquid crystalline epoxy (TLCP). Then we fabricated composites using TLCP-g-GO as reinforcing filler. The mechanical properties and thermal properties of composites were systematically investigated. It is found that the thermal and mechanical properties of the composites are enhanced effectively by the addition of fillers. For instance, the composites containing 1.0 wt% of TLCP-g-GO present impact strength of 51.43 kJ/m 2 , the tensile strength of composites increase from 55.43 to 80.85 MPa, the flexural modulus of the composites increase by more than 48%. Furthermore, the incorporation of fillers is effective to improve the glass transition temperature and thermal stability of the composites. Therefore, the presence of the TLCP-g-GO in the epoxy matrix could make epoxy not only stronger but also tougher.

The mechanical and thermal properties of epoxy were significantly enhanced modified by H20-g-PDI.

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In this study, microcrystalline cellulose fibers (MCFs) derived from sisal were treated with a hyperbranched aromatic polyamide (HBAP). The modified sisal fibers were used to produce composites with epoxy resins.Firstly the MCFs were treated with a silane coupling agent, then a HBAP was grown on the modified surface.The HBAP-MCFs were used to reinforce epoxy resins. The HBAP-MCF/epoxy composites were studied by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), dynamic mechanical analysis (DMA), and mechanical properties analysis. The results show that the HBAP-MCFs enhanced the thermal and mechanical properties of the epoxy resin. For instance, the impact strength, tensile strength, Young's modulus and toughness of the HBAP-MCF/epoxy composites with 2.0 wt% HBAP-MCFs were 32.1 kJ m À2 , 59.4 MPa, 695 MPa, and 4.37 MJ m À3 . These values represent improvements of 83.4%, 34.7%, 25%, and 178.3%, respectively, compared to a neat epoxy resin. Moreover, the addition of HBAP-MCFs produced composites with higher thermal degradation temperatures and glass transition temperatures. The HBAP-MCF swere effective in improving the thermal and mechanical properties due to a strong affinity between the fillers and the matrix.

In this report, we synthesized a new kind of liquid-crystal perylenebisimide polyurethane (LCPBI).Noncovalently functionalized reduced graphene oxide (RGO) with LCPBI was prepared via p-p stacking interactions. The noncovalently functionalized graphene nanosheets (LCPBI/RGO) were used to improve the thermal properties of epoxy composites, with modified Al 2 O 3 nanoparticles (Al 2 O 3 -APS) which were grafted with a silane coupling agent . We demonstrated that the thermal conductivity of the epoxy composites could be improved by hybrid LCPBI/RGO and Al 2 O 3 -APS fillers. For instance, the thermal conductivity of the epoxy composite with 30 wt% Al 2 O 3 -APS and 0.3 wt% LCPBI/RGO was 0.329 W m À1 K À1 , increased by 105.6% compared to that of the pure epoxy (0.16 W m À1 K À1 ). Meanwhile the glass transition temperature and storage modulus of epoxy composites with increasing hybrid fillers was improved, as well as the a-relaxation apparent activation energy.

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