Self-Forming 3D Core–Shell Ceramic Nanostructures for Halogen-Free Flame Retardant Materials

Abstract

The synthesis of aluminum phosphates-based composites has been widely studied during the past decade because of the promising industrial application of these materials. Here we show a simple one-pot heterogeneous precipitation approach to fabricate a sepiolite-phosphate (SepP) composite with adequate control of the size and dispersion of the phosphate nanoparticles. This coupling between aluminum phosphate and sepiolite nanofibers results in the development of a novel three-dimensional rigid supported phosphate structure, which is generated during the thermal treatment. According to our results, this phenomenon can be explained by a migration-coalescence mechanism of phosphate nanoparticles over the sepiolite support, assisted by a liquid phase. It is worth pointing out that this stimulant behavior observed here could have potential technological applications such as halogen-free flame retardant materials.

Advancements in traditional and nanosized flame retardants for polymers—A review

“…The formation of char is another mechanism in some fire retardant materials, such as, alumina trihydrate (ATH) that delays ignition and fire development. 41 In addition, some metal hydroxide FRs release water when decomposing at elevated temperatures, which leads to the cooling the substrate below the flash point. Subsequently, water formation favors the dilution of combustible gasses, reduces the oxygen effect, and decreases the flame spread rate.…”

Synergistic effects of polyoxometalate‐based ionic liquid‐doped sepiolite in intumescent flame‐retardant high‐density polyethylene

“…Sepiolite nanocomposite coated with aluminum phosphates (Sep@AlPO 4 ) can significantly improve the flame retardancy and mechanical properties of epoxy resin . 19,20 Therefore, functional modification of SEP with organic reagents or metallic compounds is an effective method to improve the flame‐retardant efficiency.…”

Simultaneously Improved Flame Retardance and Ceramifiable Properties of Polymer-Based Composites via the Formed Crystalline Phase at High Temperature

“…Phosphates are extensively used as binders in refractory materials, metal protective coatings, and flame retardant systems due to their thermal and chemical stability. − In phosphates, ammonium polyphosphate is an excellent nonhalogen flame retardant and widely used in flame-retarding polymer materials. During a thermal decomposition process, it releases small molecules such as NH 3 and H 2 O, and some cross-linking structures including polyphosphoric acid, etc. − Actually, the produced polyphosphoric acid, inorganic pyrophosphate, and other phosphates may act as sintering aids and adhere other inorganic fillers together, then lead to the formation of a porous and hard ceramic at high temperatures .…”