PEEK/diatomite composites byin situpolymerization: Synthesis, characterization and fundamental properties

In this study, poly (ether ether ketone)/diatomite composites (PEEK/diatomite composites) were prepared by in situ polymerization. In contrast to the direct melt‐compounding method, particles are produced with up to 25 wt % higher filler content by the in situ polymerization method. We found that filling with diatomite improved the mechanical properties of PEEK by about 15%. Scanning electron microscopy revealed that the diatomite particles are uniformly dispersed in the PEEK matrix. Furthermore, the PEEK resin penetrates into the diatomite channels to form interpenetrating organic–inorganic network structures. The thermal stabilities of the composites were studied by thermogravimetric analysis, which revealed that they possess excellent thermal stabilities; these PEEK/diatomite composites exhibit higher decomposition‐onset temperatures than virgin PEEK and lower rates of decomposition. This is attributable to interactions between the diatomite and the matrix, with the diatomite acting as a physical barrier between the polymer and the superficial zone where polymer combustion takes place.