Low-Cost Intrinsic Flame-Retardant Bio-Based High Performance Polyurethane and its Application in Triboelectric Nanogenerators

Flammability is a significant challenge in polymer-based electronics. In this regard, triboelectric nanogenerators (TENGs) have enabled a safe means for harvesting mechanical energy for conversion into electrical energy. However, most existing polymers used for TENGs are sourced from petroleum-based raw materials and are highly flammable, which can further accelerate the spread of fire and harm the ecological environment. In addition, the existing intrinsic flame-retardant TENGs are not elastic at room temperature, which may potentially damage the flexible equipment and harm firefighters. This study presents an intrinsic flame-retardant bio-based elastic phytic acid polyurethane (PUPA) synthesized using a simple and efficient one-pot polycondensation. The cross-linked structure and polar phosphorus-containing segments of PUPA are fabricated into PUPA-TENG, demonstrating a superior elasticity (elongation up to 660%), flame retardancy (UL94 V-0), impact resistance (34.71 MJ m^-3), and dielectric constant (D_k = 9.57). Consequently, this study provides a simple strategy for tailoring TENGs toward environmentally friendly and secure power generators and electronics, which can effectively reduce fire hazards and potentially be applied to other fire-risk fields such as personal protection, firefighting, and new energy.