The effect of calcite on the mechanical, morphological and thermal properties of virgin and recycled thermoplastic copolyester elastomer composites

Abstract

In this study, the effects of stearic acid-coated calcite (CaCO₃) were investigated on the mechanical, thermal, and morphological properties of thermoplastic copolyester elastomers (COPE or TPE-E) and recycled COPEs (R-COPE). R-COPE, which consist of process wastes that are qualified as postindustrial recycled (PIR), were physically 100% recycled. The composites (virgin and recycled COPE) containing different concentrations of calcite (5–30 wt%) were prepared by melt compounding. It has been determined that mechanical properties such as impact strength and modulus increase with calcite concentration, while tensile strength decreases at higher concentrations owing to the stronger interfacial relationships between the polymer matrix and filler. Morphological studies revealed a good dispersion of calcite fillers at lower concentrations in the polymer matrix. The final composites obtained from recycled polymer had almost similar mechanical properties compared to virgin ones. This showed that recycled COPE could be used in many areas specifically automotive industry, as it gave results close to its original state with the addition of calcite with decreased cost.

Highlights

• COPE were melt-blended with stearic acid-coated calcite (CaCO₃).
• Recycled-COPEs were obtained from the physical recycling of factory production waste.
• The mechanical properties such as tensile modulus increased with calcite concentration.
• The thermal properties increased with increasing calcite concentration.
• R-COPE composites were obtained without any decrease in properties.