Designing of layered double hydroxide, metal oxides, and borate‐reinforced thermoplastic polyurethanes composites

Abstract

Thermoplastic polyurethanes (TPUs) are widely used in automotive, medical, and marine applications due to their excellent properties such as high tensile strength, flexibility, and durability. However, the presence of isocyanate groups in TPUs increases their flammability and produces toxic gases during combustion, limiting their application. Here, the study aims to modify TPUs to improve their flame‐retardant behavior. Various fillers such as metal oxides, Layer double hydroxides (LDH), and borates were synthesized and added into the TPU matrix by using extrusion and compression molding. At a 10% loading of Zinc‐Magnesium oxides, a limiting oxygen index (LOI) of 25% was achieved, along with no dripping and complete burning cessation within 20 s. Magnesium aluminium LDH exhibited maximum flame retardancy at a 5% loading, with an LOI of 25%, burning cessation within 23 s without dripping, and a V1 rating. Overall, this research aims to develop TPU composites with improved fire safety properties by incorporating various additives. The synthesized additives showed potential for enhancing the mechanical, thermal, and flame‐retardant properties of TPU.