Achieving superior fire safety for TPU 3D‐printed workpiece with EP/PBz/PDMS coating

Abstract

Abstract To reduce the possibility of the TPU 3D‐printed workpiece causing a fire, a flame‐retardant coating containing phosphorus, nitrogen, silicon, and benzene rings was fabricated on the TPU workpiece surface. When the MSDS content in the coating is 30 phr, the coated TPU composites LOL reached 29.5%, achieved V‐0 rating at the UL‐94 test and its peak heat release rate was reduced by 71.3% in the cone calorimeter test. When the MSDS content was increased to 20 phr, a continuous char layer was observed. Moreover, the EP/PBz/PDMS coating improved the thermal stability and tensile strength of TPU 3D‐printed workpiece. When the coating burns, it forms a dense charcoal layer, which isolates oxygen. The substrate wrapped by the charcoal layer undergoes a carbonization reaction when heated, preventing the substrate from burning further, resulting in improved flame retardancy, smoke suppression and dripping resistance of TPU.