Search

Polycarbonate (PC) is known for its high impact resistance and transparency. However, fabricating flame-retardant and scratch resistant PC without sacrificing its mechanical properties and transparency remains a great challenge. Herein, we prepared a highly transparent and fast curing coating (DA-AE) composed of imidazole-based flame-retardant curing agents (DA) and epoxy-oligosiloxane (AEOS) via imidazole-induced anionic polymerization. The curing time of DA-AE coating was only 8 min at 130 °C. The presence of the coating significantly improved the flame retardancy and scratch resistance of PC films. In contrast to the uncoated PC films, the PC/DA-AE sample self-extinguished within 1.2 s in the vertical burning test and achieved a limiting oxygen index of 27.1 %. In the cone calorimeter test, the PC/DA-AE sample exhibited a notable 49.1 % reduction in the peak heat release rate compared to that of the PC films. Additionally, the pencil hardness of PC/DA-AE-2 was increased to 6H from 2B of the control PC film. The coating exhibited good adhesion to the PC substrate and achieved the highest grade in the cross-cut test without any surface pre-treatment. Remarkably, the coating showed strong chemical and mechanical stability during tests of wiping cycles with different solvents and bending cycles. This work provided a simple and efficient strategy for large-scale producing transparent flame-retardant and scratch resistant PC films. [Display omitted] • A transparent and flame-retardant coating (DA-AE) was prepared via imidazole-induced anionic polymerization. • The DA-AE coating simultaneously improved the surface hardness and flame retardancy of PC films. • The coated PC films showed high transparency, solvent wiping resistance and good flexibility. [ABSTRACT FROM AUTHOR]