Polymer nanocomposites:In situpolymerization of polyamide 6 in the presence of graphene oxide

Abstract

Polyamide 6 (PA6)/graphene oxide (GO) nanocomposites were prepared via in situ, ring opening polymerization of e-caprolactam in the presence of both dried powder and colloidally dispersed single layer GO. Characterization of the composites and GO (both as received and after removal from the composites) was carried out using atomic force microscopy (AFM), Fourier transform infra-red spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis, differential scanning calorimetry and tensile testing. Reduction in the GO during polymerization was observed. So too was functionalization of the GO flakes with PA6 chains. FTIR demonstrates the retention of some carbonyl oxygen functionalities after polymerization. AFM imaging indicated the presence of single layer GO and the sheet height increased to $4 nm for graphene sheets after polymerization. This suggests the graphene acts as a base for polymer chain formation, leading to good interfacial interaction between the filler and matrix. Raman data show no evidence of the restoration of sp2 hybrid as a result of polymerization. The nanocomposites are thermally stable while molecular weight and crystallinity have both been affected by GO inclusion. A percentage linear increase in Young's modulus was observed as colloidally dispersed GO content increased.

Preparation and properties of polyamide 6 nanocomposites covalently linked with amide functional graphene oxide

“…The results reported herein are a continuation of our previous studies of PA6/GO composites prepared through in situ polymerization. 17,18 This study was encouraged by the work of Gao et al in the Journal of the American Chemical Society . 19 Wherein is reported the successful functionalization of single-walled CNTs with an amide group and their inclusion in a PA6 composite with improved mechanical properties.…”

Preparation and Characterization of Polyamide‐6/Reduced Graphene Oxide Composite Microspheres

“…First, based on that graphene oxide (GO) has the abundance of functional groups to provide the sufficient reaction sites for PA6 molecules to interact with it and reduction of GO is a common method to prepare graphene, an effective way is to modify graphene with GO being used as a raw material . Second, compared to dried GO powder, colloidally dispersed GO prevents agglomeration better and has enhanced dispersion within the system when added to the caprolactam (CL) melt . Third, in a range of techniques including melting blending, solvent blending and other methods, in‐situ polymerization of CL offers great superiority in making graphene homogeneously dispersed in the PA6 matrix …”

“…[12] Second, compared to dried GO powder, colloidally dispersed GO prevents agglomeration better and has enhanced dispersion within the system when added to the caprolactam (CL) melt. [13] Third, in a range of techniques including melting blending, solvent blending and other methods, in-situ polymerization of CL offers great superiority in making graphene homogeneously dispersed in the PA6 matrix. [10g,14] According to the above-mentioned and our previous work, [4a] a novel method of preparing PA6/graphene composite microspheres is proposed in this paper by using CL, GO/water pulp and polystyrene (PS) as raw materials.…”

Effect of flake size on thermal properties of graphene oxide/poly(methyl methacrylate) composites prepared via in situ polymerization

“…Generally, GO/polymer composites are prepared through melt blending, solution blending, or in situ polymerization . Among the three methods, in situ polymerization is an efficient method to improve the dispersion of the fillers in the polymer matrix, and confer a strong interaction between the reinforcing filler and the polymeric phase . Tripathi et al .…”