Thermal and mechanical properties of fluorinated ethylene propylene and polyphenylene sulfide-based composites obtained by high-energy ball milling

Solid-state formation method of polyimide (PI) blends based on polyphenylene sulfide (PPS) and fluorinated ethylene propylene (FEP) was elaborated. Recycled thermoset PI powder was used as reinforcements. FEP/PI and PPS/PI blends were obtained by high-energy ball mill without using compatibilizer. PI content in blends was of 25, 50 or 75 wt%. Bulk samples were obtained by sintering at 330 °C during 25 min, with consequent disposition of sample into hot mold between two cold plates and loading the pressure of 20–35 MPa for 10 min. Morphology structure and thermal properties of powder blends were studied by tapped density measurements, DSC and XRD analyses. Thermal and mechanical properties of bulk samples were studied by DMA, hardness measurements and compressive tests. Strong chemical interaction between FEP matrix and PI filler was observed, whereas in case of PPS/PI samples nearly no interaction between components was found. Mechanical tests show that optimum filling degree for PPS/PI system is of 25 wt% PI, whereas in FEP/PI system it is of about 50 wt%.