Evaluation of the Influence of Fibre Aspect Ratio and Fibre Content on the Rheological Characteristic of High Yield Pulp Fibre Reinforced Polyamide 11 “HYP/PA11” Green Composite

The rheological behavior of composites made with low-density polyamide 11 (PA11) and high yield pulp fibre (HYP) is evaluated. The rheological properties of high-yield, pulp-reinforced bio- based Nylon 11 HYP/PA11 composite were investigated using a capillary rheometer. The rheological tests were realized in function of the shear rate for different temperature conditions. The experimental results showed that identically for fibre content and aspect ratio, the shearing effects decreased as the temperature increased; that is, the HYP/PA11 became more non-Newtonian in the higher temperature region, which corresponds to the high pseudoplasticity of the HYP/PA11. At low HYP content, the shear viscosity is expected to increase rapidly with increasing concentrations of the fibres because of the rapidly increasing interactions between particles as they become more closely packed. However, at very high fibre content, random anisotropic structure of the fibres in polymer melts is created. The increase in shear viscosity is greater at lower shear rates, where fibre and polymer molecules are not completely oriented.