A flame-retardant PET fabric coating: Flammability, anti-dripping properties, and flame-retardant mechanism

Polyethylene terephthalate (PET) fabrics are used almost everywhere in daily life. However, they burn with melting and dripping, causing potential dangers. This work aims to solve the melt-dripping phenomenon and improve the flame retardancy of PET fabrics. Through a rapid dip-coating process, the chemically reactive product of phytic acid and (3-piperazinylpropyl)methyldimethoxysilane, denoted as GPA, was used to prepare a flame-retardant coating for PET fabrics. The results of the scanning electron microscope and energy dispersive spectrometry show that GPA is evenly distributed on the PET fabrics. From the thermogravimetric analysis in air atmosphere, the residual chars of flame-retardant PET (FR-PET) fabrics at a higher temperature zone increase significantly. The melt-dripping is eliminated in the vertical flaming test. Besides, the limiting oxygen index values of FR-PET fabrics are improved. In the microscale combustion calorimetry test, the peak heat release rates (PHRR) of FR-PET fabrics are effectively reduced. In the cone calorimetry test, the PHRR and total heat release of FR-PET fabrics are also reduced. The results of the thermogravimetric analysis coupled with Fourier transform infrared analysis show that FR-PET fabrics release fewer combustible products during the thermal decomposition process. In the tensile strength test, the warp tensions of FR-PET are enhanced. This work demonstrates the flame-retardant effectiveness of GPA on PET fabrics in detail.