Effect of aspect ratio of synthetic Wollastonite nanofibers on mechanical, thermal and flammability properties of polyoxymethylene nanocomposites

Polyoxymethylene (POM) nanocomposites were reinforced with 1 phr of synthetic wollastonite nanofibers (SWN) to investigate the effect of the aspect ratio of SWN on the mechanical, thermal and flammability properties. The tensile strength, Young's modulus, and impact strength of POM nanocomposites demonstrated an increasing trend as the aspect ratio of SWN increased. POM nanocomposites incorporated SWN with an aspect ratio of about 20 (POM/SWN‐20) exhibited higher tensile strength (2%), Young's modulus (3%) and impact strength (50%) as compared to that of about 5 (POM/SWN‐5). A higher aspect ratio of SWN also contributed to the better thermal stability of POM nanocomposites, in which the initial degradation temperature of POM/SWN‐20 was about 6°C higher than POM/SWN‐5. Interestingly, SWN that possessed a lower aspect ratio performed better in flame retardancy, as indicated by the increase in the time to ignition and the decrease in the peak heat release rate. This present study demonstrates the relationship between the aspect ratio of filler (SWN) with the polymer matrix (POM), which is crucial in producing nanocomposites that have great potential in automotive applications. The tensile strength, Young's modulus, and impact strength of POM nanocomposites demonstrated an increasing trend as the aspect ratio of SWN increased. A higher aspect ratio of SWN also contributed to the better thermal stability of POM nanocomposites, in which the initial degradation temperature of POM/SWN‐20 was about 6°C higher than POM/SWN‐5. Interestingly, SWN that possessed a lower aspect ratio performed better in flame retardancy, as indicated by the increase in the TTI and the decrease in the PHRR.