Metal–Organic Frameworks Derived from Zn and p-Hydroxybenzoic Acid for Smoke Suppression and Flame Retardation in Vinyl Resin

A metal–organic framework (MOF) formed between Zn and p -hydroxybenzoic acid (PHBA) is synthesized using a solvothermal method. These Zn-PHBA nanorods, which are inexpensive and suitable for mass production, are added as a flame-retardant into vinyl resin (430 LV, a material used in marine composites). Data from cone calorimetric test demonstrates that adding the Zn-PHBA nanorods to 430 LV significantly improves flame retardation and smoke suppression. At a high Zn-PHBA content of 10.0 wt%, the limiting oxygen index of 430 LV increases from 19.5% to 28.5%, and the material reaches the V-0 rating in vertical burning tests (UL-94). Moreover, the tensile and impact strengths of 430 LV containing 10 wt% Zn-PHBA as flame-retardant do not deteriorate and are even slightly improved. This work demonstrates that this MOF synthesized by a simple and efficient method may be used to produce nanocomposites with excellent flame retardation and mechanical properties, while keeping the material cost sufficiently low for marine applications.