Surface Functionalization of Graphene Oxide with Polymer Brushes for Improving Thermal Properties of the Polymer Matrix

Abstract

In this work, polymethyl methacrylate (PMMA) and polystyrene (PS) with controlled structures would be grafted on graphene material. The hybrid materials were prepared by coating graphene oxide (GO) with polydopamine (PDA) as a reactive underlayer and reducing agent, subsequently, surface-initiated polymerization of monomers (methyl methacrylate, styrene) based on the activators regenerated electron transfer atom transfer radical polymerization (ARGET-ATRP) technique. The polymer brush-modified graphene materials were then incorporated into the PMMA or PS matrix to get polymer nanocomposites with better thermal properties. The results of Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA) demonstrated that PMMA and PS chains were successfully anchored on the surfaces of functionalized GO sheets. The influence of the grafted polymer brush-modified GO on thermal stability of PMMA and PS was investigated by a simultaneous thermal analyzer. Thermal conductivity of the polymer nanocomposite was determined by a conductive calorimeter. The results showed that thermal stability, glass transition temperature ( T g ), and thermal conductivity of the polymer nanocomposites were obviously improved compared with pure PMMA or PS.

Hyper-Cross-Linked Nanoparticle Reinforced Composite Polymer Electrolytes with Enhanced Ionic Conductivity and Thermal Stability for Lithium-Ion Batteries

“…In addition, thermogravimetric analysis (TGA) was used to research the thermogravimetric process of composite nanoparticles before and after hyper-cross-linking, as shown in Figure b and Figures S3 and S4 . SiO 2 @CPs and SiO 2 @HCPs experienced decomposition of the partial oligomer, breaking of the KH570-PMMA-PS group, and the removal of chain segments from 100 to 450 °C. , The weight residual rate of SiO 2 @HCP is higher than that of SiO 2 @CP (about 3%), which demonstrates that SiO 2 @HCPs exhibit better thermal stability than SiO 2 @CPs due to the successful synthesis of hyper-cross-linked networks …”

“…SiO 2 @CPs and SiO 2 @HCPs experienced decomposition of the partial oligomer, breaking of the KH570-PMMA-PS group, and the removal of chain segments from 100 to 450 °C. 44,45 The weight residual rate of SiO 2 @HCP is higher than that of SiO 2 @CP (about 3%), which demonstrates that SiO 2 @HCPs exhibit better thermal stability than SiO 2 @CPs due to the successful synthesis of hyper-cross-linked networks. 42 The specific surface area and pore size distribution of SiO 2 @ CP-1 and SiO 2 @HCP-1 before and after hyper-cross-linking were characterized by the analysis of the N 2 adsorption− desorption isotherm at 77 K, as shown in Figure 1c, d.…”

Dielectric Properties and Flexibility of Polyacrylonitrile/Graphene Oxide Composite Nanofibers

“…The emergence of the carbon peak was in line with the EDX analysis. The peak of moderate intensity at 1716 cm –1 indicated the CO stretching of carboxylic acid. − The peak at 1579 cm –1 is a symmetrical CC stretching vibration of the aromatic group, and the peak at 1103 cm –1 can be attributed to the C–C asymmetric stretching vibration of the aromatic group. , In addition, the two shoulder peaks at 2848 and 2927 cm –1 corresponded to the C–H aromatic sp strain vibrations. , In the FTIR GO spectrum, the hydroxyl and carboxyl peaks have indicated oxidation. , The insertion of functional oxygen-carrying groups in the GO form exhibited that the acidic and oxidative compounds successfully modified the surface, and this is in line with the SEM and TEM results.…”

“…61−63 The peak at 1579 cm −1 is a symmetrical C�C stretching vibration of the aromatic group, and the peak at 1103 cm −1 can be attributed to the C−C asymmetric stretching vibration of the aromatic group. 61,64 In addition, the two shoulder peaks at 2848 and 2927 cm −1 corresponded to the C−H aromatic sp 2 strain vibrations. 65,66 In the FTIR GO spectrum, the hydroxyl and carboxyl peaks have indicated oxidation.…”

Electrical Properties of Polyetherimide-Based Nanocomposites Filled with Reduced Graphene Oxide and Graphene Oxide-Barium Titanate-Based Hybrid Nanoparticles

“…In this regard, the poly (monomethyl itaconate)-grafted-graphene oxide can react with barium titanate functionalized with amine groups by nucleophilic substitution reaction. The amine-functionalized barium titanate is prepared by subsequent reactions of hydroxylation and silanization by using 3-aminopropyltriethoxysilane [ 20 ]. We hypothesize that the carboxylic acid and ester side groups of poly(monomethyl itaconate) are susceptible to the nucleophilic attack of amine groups, promoting the formation of covalent bonds that links graphene oxide sheets with barium titanate nanoparticles ( Figure 1 ).…”