Morphology and melt rheology of nylon 11/clay nanocomposites

Abstract

Nylon 11 (PA11)/clay nanocomposites have been prepared by melt-blending, followed by melt-extrusion through a capillary. Transmission electron microscopy shows that the exfoliated clay morphology is dominant for low nanofiller content, while the intercalated one is prevailing for high filler loading. Melt rheological properties of PA11 nanocomposites have been studied in both linear and nonlinear viscoelastic response regions. In the linear regime, the nanocomposites exhibit much higher storage modulus (GЈ) and loss modulus (GЉ) values than neat PA11. The values of GЈ and GЉ increase steadily with clay loading at low concentrations, while the GЈ and GЉ for the sample with 5 wt % clay show an inverse dependence and lie between the modulus values of the samples with 1 and 2 wt % of clay. This is attributed to the alignment/orientation of nanoclay platelets in the intercalated nanocomposite induced by capillary extrusion. In the nonlinear regime, the nanocomposites show increased shear viscosities when compared with the neat resin. The dependence of the shear viscosity on clay loading has analogous trend to that of GЈ and GЉ. Finally, a comparison has been made between the complex and steady viscosities to verify the applicability of the empirical CoxMerz rule.

A Study on the Structure and Adhesive Properties of Epoxy-Silicate Composites

“…Figure 2 shows relations between the viscosity h and the shear stress t for blends with different fillers. It is seen that the introduction of fillers, as expected, leads to some increase in viscosity of the epoxy oligomer, as is also shown in other studies on the rheology of nanocomposites [14][15][16][17]. This fact can probably be explained by the interaction between the filler and polymer as a result of dispersion of layered silicates in the matrix, which leads to an increased resistance to the flow/ deformation of suspension and, thus, to an increased viscosity.…”

“…Also, it was intended to estimate the dispersion quality of particles and the structure of the nanocomposites obtained. Since the rheological properties of suspensions with different particles are rather sensitive to the structure of the system, the size of particles, their shape, and conditions on their surface, rheology gives interesting possibilities for evaluating the dispersity of particles in polymers, as shown in [13][14][15][16][17][18][19][20].…”

Highly dispersed polyamide‐11/halloysite nanocomposites: Thermal, rheological, optical, dielectric, and mechanical properties

“…Nevertheless, recent literature suggests that the microstructure and ultimate properties of PA-11 can be modified by the addition of nanofillers such as MMTs or CNTs. [19][20][21][22] Unfortunately, the reported results appear to be contradictory. Liu et al 19 mentioned a negligible enhancement in mechanical properties of PA-11 even at high organoclay loadings which was ascribed to incomplete exfoliation of nanoparticles.…”

Unique Shear Flow Rheological Characterization of Nylon 6 and Its Nylon 610-Based Blends

“…[1] Rheological characterization is regarded as the essential to obtain plastic products with outstanding quality and improving production efficiency during extrusion molding and injection molding. This has resulted in most of the literature concentrating on polyolefin melt rheology [2][3][4] and relatively little on condensation polymers, [5,6] such as the nylons.…”