Multifunctional thermoplastic polyurethane composites with excellent flame retardancy, strain-sensitivity, water penetration resistance and breathability

To improve the fire safety of combustible materials in wearable applications, it is urgent to design multifunctional fabrics with the ability of flame-retardancy and comfortable wearability. Herein, the ultra-fine ammonium polyphosphate (APP) prepared by ball milling was added to polyurethane (TPU) spinning solution. The blended fiber membrane was obtained by co-spinning, then sprayed MXene to form a TPU/APP/MXene fiber membrane. The synergistic charring effect of APP and MXene endows the membrane with excellent flame-retardancy. Due to the high conductivity and hydrophobicity of MXene covered on the surface and the structural characteristics of porous membrane, the TPU/APP/MXene fiber membrane also has excellent strain sensitivity, water penetration resistance, breathability and electrothermal properties, among other multifunctional properties. Co-spinning strategy provides a new platform for the construction of multifunctional composite fiber membrane, which is of great value in widely solving wearable safety problems.