A simple mixing method for polyamide 12/attapulgite nanocomposites: structural and mechanical characterization

In this work, the attapulgite (ATP) was used as a promising mineral clay to prepare polyamide 12 (PA12) matrix polymer nanocomposites. ATP has a relatively low cost compared to other nanoclays and is a very abundant raw material in the northeast region of Brazil. The ATP was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy and field emission gun scanning electron microscopy (FEG-SEM). The PA12/ATP nanocomposites with 0, 1, 2.5, 5, 7.5 and 10 wt% of ATP were prepared using a simple blending method in a high-speed thermokinetic homogenizer (3000 rpm) in which the melting of the PA12 and the mixture with ATP occurred by friction, followed by hot pressing and stamping of the specimens. The nanocomposites were characterized by mechanical properties, the degree of crystallinity and crystallite size were calculated by XRD, and the morphological characteristics were observed by SEM. The addition of ATP in the PA12 matrix increased the modulus of elasticity, hardness, degree of crystallinity and the apparent crystallite size of the nanocomposites. The addition of up to 5 wt% of ATP increased tensile strength and deformation at break; for higher concentrations, the dispersion was not efficient. A major advantage of using ATP as a reinforcement agent for PA12 is the low cost of this material plus the great interaction with PA12 which can dispense the use of compatibilizer agents and/or surface modification in the ATP, making it a potential material to extend PA12’s range of applications.