Durability evaluation of mechanical and thermal properties of graphite–copper hybrid powder filled polypropylene composites

Abstract

The sustainability of polymer composites in real time environments can be ensured by durability studies. This paper aims to evaluate the durability of mechanical and thermal properties of graphite (G) and copper (Cu) particle-filled polypropylene (PP) composites. Three types of composites, PP/G, PP/Cu, and PP/G/Cu, were prepared by melt compounding and compression molding. The compressive strength, microhardness, and thermal properties of the composites were tested after 2 and 90 days of storage under ambient conditions. The results showed a noticeable decrease in the compressive strength of the composites, reaching ∼60–70 % compared to that of the neat PP and showed a ductile-like fracture mode. A further decrease in the strength values of ∼90 % occurred when the composites were tested after 90 days and a brittle-like fracture mode was observed. The addition of G and Cu to PP improved its microhardness and a drastic decrease also appeared after 90 days compared to that of their counterparts tested after 2 days. DSC measurements showed that the melting temperature, T m, decreased and crystallization temperature, T c, increased indicating a better ability of the fillers for nucleation in PP and obstructing its crystal growth. The degree of crystallinity, X c, of PP in the composites decreased compared to that of the neat PP and it increased when tested after 90 days compared to that tested after 2 days.

High‐quality modification of general polypropylene by the synergistic effect of zinc adipate, hydrotalcite, and polypropylene (SP179)

“…Meanwhile, numerous step‐like grooves were observed in the impact section as can be observed in the local magnification, indicative of the ductile fracture of modified iPP. This ductile fracture due to fillers debonding can also be found in the studies of Al‐Samhan and Al‐Attar 50 and Dweiri 51 …”

“…This ductile fracture due to fillers debonding can also be found in the studies of Al-Samhan and Al-Attar 50 and Dweiri. 51 From Figure 4g, with the addition of 50% SP179, the pits at the impact section of iPP became significantly less, indicating that the phase adhesion between the nucleating agent and SP179 particles and the iPP matrix is better and that voids are observed on the iPP surface when deformation occurs as a result of external forces; these voids resisted the external impact by combining with each other or growing to form shear bands in iPP, thus enhancing the notch impact strength. From Figure 4c1-g1, the average diameter (d n ) values of the pits can be estimated by using Nano Measurer software, it showed in Table 1, For each sample counted, the number of the pits was not less than 50.…”