Development of geopolymer derived from slag waste based composite film on cotton fabric: A preliminary approach for flame retardant behavior

Abstract

Organic-inorganic hybrid composite films with a geopolymer and organic polymers (sodium polyacrylate, polytetrafluorethylene, and polyurethane) were prepared using a facile method for application as flame retardant coatings. The geopolymer paste was successfully synthesized by adding a mixture of metakaolin and slag into an alkali solution. The structural and morphological properties of the barrier films were investigated using Fourier-transform infrared spectroscopy and scanning electron microscopy. The films showed the Si-O and Si-Al peaks characteristic of the geopolymer. The microstructural examination revealed that the films consisted of irregular particles. With an increase in the geopolymer amount, the flexural and compressive strengths of the samples decreased. The tensile strength, thermogravimetric analysis and flame retardant properties of the composite paste were investigated. The films showed a tensile strength of 0.15–0.30 MPa. The composite film coated onto cotton surface was thermally stable up to 200 °C. The cotton (C) and the mixture of cotton and polyester (M) substrates coated with the barrier film showed the char lengths of 5–8 and 4–7 cm, respectively. The geopolymers synthesized using slag and metakaolin exhibited excellent flame retardant properties on the cotton fabric. Hence, these films were found to be promising candidates for flame retardant applications.