A new application of recycled-PET/PAN composite nanofibers to cement–based materials

In these days, the inappropriate disposal of polyethylene terephthalate (PET) causes severe environmental problems and, for this reason, it is necessary to develop alternatives for the efficient use of this material. This study presents an application of a new type of composite nanofibers made with recycled PET and polyacrylonitrile (RPET/PAN) recently synthesized and characterized by Scanning Electron Microscopy (SEM), Fourier-Transformed Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). The composite was added to cementitious materials to improve the mechanical and durability properties, making it a viable alternative in PET recycling. With this aim, the following properties were evaluated to mortars prepared with small amounts of these nanofibers: mechanical (compressive and flexural resistance), of the microstructure (fiber adherence) and durability (total porosity, effective porosity, capillary absorption, and resistance to water penetration). These nanofibers have an average diameter of 402 nm and good mechanical properties. Among other important results, the material showed an increase in compressive and flexural strength, and a decrease in drying shrinkage of up to 26.1, 89.1 and 93.1% in comparison with a reference mortar, respectively.