Preparation of a Novel Organic Phosphonic Acid Intercalated Phosphate Tailings Based Hydrotalcite and Its Application in Enhancing Fire Safety for Epoxy Resin

Abstract

Phosphate tailings (PTs) are solid waste, which is produced by phosphate flotation. In this work, PTs were used as raw materials for the preparation of diethylenetriamine pentamethronic acid (DTPMP) intercalated trimetal (Ca-Mg-Al) layered double hydroxides (TM-DTPMP LDHs) by co-precipitation method. TM-DTPMP LDHs were characterized by X-ray diffraction, fourier-transform infrared spectroscopy, scanning electron microscopy, differential thermal gravimetric analysis, X-ray photoelectron spectroscopy and applied as a flame retardant to improve the fire safety of epoxy resin (EP). The results showed that the composite materials exhibited obvious layered structure. After intercalation, layer spacing increased from 0.783 to 1.78 Å. When the amount of TM-DTPMP LDH in EP was 8%, the limitted oxygen index of the composite material increased from the original 19.2% to 30.2%. In addition, Cone calorimeter (CC) and Raman spectrum results indicated that with the addition of TM-DTPMP LDHs, the value of heat release rate peak (pHRR) and total heat release (THR) were reduced by more than 43% and 60%, while the value of smoke formation rate (pSPR) and the total smoke production (TSP) decreased nearly 64% and 83%, respectively. The significant reduction in the release of combustion heat and harmful smoke during EP combustion may be attributed to the synergistic flame-retardant effect between hydrotalcite and DTPMP. This work exhibited great potential for the green recycling of PTs and the enhancement of the fire safety of EP.

Research on Recycling of Phosphorus Tailings Powder in Open-Graded Friction Course Asphalt Concrete

“…The DSR test contains two models, the temperature sweep test and frequency sweep test, targeting the complex shear modulus (G*) and rutting factor (G*/sinδ). The composite shear modulus G* represents the asphalt's ability to resist flow deformation, and the rutting factor G*/sinδ is commonly used to evaluate the rutting resistance of asphalt [3]. The specimens are the basic asphalt binder, and five powder-asphalt mortars with a 4%, 7%, 10%, 12%, and 15% mass percentage.…”

“…Phosphorus tailings are a typical by-product [3] in phosphate mining and flotation processes. When 1 ton of phosphorus concentrate is produced, it will generate 0.4 tons [4,5] Materials 2023, 16, 2000 2 of 13 of phosphorus tailings.…”

Preparation of PO43−-Intercalated Calcium–Aluminum Hydrotalcites via Coprecipitation Method and Its Flame-Retardant Effect on Bamboo Scrimber

“…In recent years, layered double hydroxides (LDHs) have been emerging as a new generation of environmentally friendly flame-retardant material, which is a new type of layered inorganic functional material made of a positively charged main layer and interlayer region containing charge-compensating anions [ 6 , 7 ]. Its general formula is , where and denote divalent and trivalent cations located on the main layer, e.g., Mg 2+ , Fe 2+ , Zn 2+ , Al 3+ , Cr 3+ , Fe 3+ , etc.…”

Preparation of a Novel Phosphorus–Nitrogen‐Containing Flame Retardant by Supramolecular Reaction and its Application in Epoxy Resin

“…Zhang et al found that the EP composite containing 8 wt% of DTPMP intercalated trimetal (Ca–Mg–Al)‐layered double hydroxides can lead to a significant reduction in the release of combustion heat and harmful smoke. [ 4 ] Wang et al synthesized tin ethylenediamine tetra‐methylene phosphonate (TETP) and found that the EP composite with 7.0 wt% of TETP can pass UL‐94V‐0 rating with a limiting oxygen index (LOI) value of 29.5%. [ 5 ] Unfortunately, although satisfied flame retardancy was achieved in some previous studies, they sacrificed the good mechanical properties and impeded the practical application of EP composites.…”