The objective of this work is to study the effect of the addition of the compatibilizing agent poly(ethylene-alt-maleic anhydride) (HDPE-alt-MAH) on the mechanical properties and morphology of HDPE/PA12 blends. The amounts of compatibilizer used were 0, 2, and 3 wt% and HDPE/PA12 blends were manufactured in three ratios, namely: 75/25, 50/50, and 25/75. It was observed that the blends with 2 wt% of HDPE-alt-MAH presented the best mechanical performance. As the proportion of PA12 in the blend increased, the mechanical strength and elongation at break also increased. The creep behavior of the blends was also evaluated, and it was verified that the steady-state creep rate decreases with the increase of PA12 showing the greater resistance to deformation of PA12 compared to HDPE. The viscoelastic behavior of the materials varied with the composition, but by creep compliance analysis, it was observed that the elastic behavior of the blends was similar. The rheology of the blends was analyzed, and it was concluded that the 75/25 HDPE/PA12 blend had the best processability. From the analysis of the microstructures of the blends, it was possible to correlate the phase dispersion with the mechanical and rheological properties.

Soapstone is an abundant mineral in Ouro Preto ‐ Minas Gerais, Brazil and its main destination is in the production of craftsmanship. Rock recovery in those activities is low and the waste disposal is done with little control, which can be hazardous to the environment. This work proposes an alternative use of such potentially harmful waste as reinforcement in a novel polymer matrix composite, which can be particularly attractive to the automotive industry and of which very little information is available elsewhere in the literature. Firstly, the characterization of the waste was performed. Particle size and shape parameters were determined by automated image analysis and the mineralogical composition was determined by X‐ray diffraction, infrared, and Raman spectroscopy. High‐density polyethylene was used as matrix and the composites were made in three matrix/filler ratios: 90/10, 80/20, and 70/30 by weight. Tensile and rheological properties were measured in order to determine the influence of the particles on the polymer mechanical behavior and processing conditions. The materials showed a pseudoplastic behavior and the filler's influence was more pronounced in the 70/30 composites, which showed higher viscosities than the neat polymer. The addition of particles resulted in more brittle and rigid composites, with higher values of tensile strength.

This work studies the crystallinity and rheology of HDPE/PA12 blends compatibilized with 2 wt% of HDPE‐alt‐MAH. Specimens of HDPE/PA12 blends were extruded and injected into a mold with 75/25, 50/50, and 25/75 HDPE/PA ratios. The Fourier‐transform infrared spectroscopy (FTIR) analysis showed that no oxidation reaction occurred in the high‐temperature processing and that stronger interactions between the components of the blends occurred in the polyamide's functional groups. The x‐ray diffraction (XRD) analysis showed that the crystallinity degree of the blends and the mean crystallite sizes decreased with the addition of PA12 for both blends. The HDPE's lattice parameters were consistent with the values in the literature, whereas for the PA12, it was not possible to fit its lattice parameters. The rheology analysis evaluated the relationship between the shear stress and viscosity and found that the HDPE/PA 75/25 blend was the most pseudoplastic, presenting the best processability under high shear rates.