Comparative morphological, thermal, and mechanical characteristics of doped bentonite and dolomite natural clay fillers into high‐density polyethylene

Abstract

Organic–inorganic composites have attracted great interest, due to their remarkable impact, causing improvements in the mechanical properties of polymers when compared with their pure forms. Hence, this study has been attempted to investigate and compare the various properties of high‐density polyethylene (HDPE), separately doped with two different types of clay minerals using melt‐mixing and compression‐molding techniques. The fourier transform infrared spectroscopy (FT‐IR), x‐ray diffraction (XRD), and scanning electron microscope (SEM) were used to characterize the structural and morphological properties of the resulting composites, while, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were employed to characterize their thermal properties. Morphological investigations indicated homogeneous dispersion of both clay materials in the HDPE matrix. Moreover, an investigation was conducted on the mechanical properties of composites, including elastic modulus, yield stress, tensile strain at break, tensile strain at yield, tensile stress at break, and ultimate tensile strength. According to the mechanical data, adding 6.0 wt% of bentonite or dolomite to HDPE led to an increase in the elastic modulus up to 125% and 116% increments, respectively. An increase in the filler content in the composite from 2.0 to 8.0 wt% resulted in a slight decrease in tensile stress at break, yield stress, tensile strain at break, and tensile strain at yield.