Iron stearate

• CAS: 5136-76-5
• Catalog Number: ACM5136765
• Category: Main Products
• Molecular Weight: 905
• Molecular Formula: (C₁₇H₃₅COO)₃Fe
• Synonyms: iron (II) stearate; iron(II) stearate; iron(II)stearate; iron stearate
• IUPAC Name: iron(3+); octadecanoate
• InChI Key: XHQSLVIGPHXVAK-UHFFFAOYSA-K
• Appearance: Orange powder
• Exact Mass: 339.19900
• H-Bond Acceptor: 6
• H-Bond Donor: 0

Case Study

Study on the Structure, Composition and Application of Iron Stearate as Precursors for Iron Oxide Nanoparticles

Perton, Francis, et al. Inorganic Chemistry 60.16 (2021): 12445-12456

This study systematically investigated the molecular structure, composition, and application of two iron stearate precursors (FeSt₂ and FeSt₃) in synthesizing iron oxide nanoparticles (IONPs) via thermal decomposition. FeSt₂ and FeSt₃ were synthesized by coprecipitation of ferrous chloride/ferric chloride with sodium stearate in aqueous solution, with stearate-to-iron ratios of 2 and 3 respectively. Comprehensive characterizations using MALDI-TOF MS, EPR, Mössbauer spectroscopy, XRD, and SAXS revealed that FeSt₂ mainly consists of [Fe₃(μ₃-O)St₆·xH₂O]Cl with chelate-coordinated carboxylates and a lamellar structure (d(001)=49.5 Å). FeSt₃ is a mixture of [Fe₇(μ₃-O(H))₆(μ₂-OH)ₓSt₁₂₋₂ₓ]St, [Fe₃(μ₃-O)St₆·xH₂O]St, and free stearic acid, with bridging-coordinated carboxylates and a more complex lamellar structure. Thermal decomposition of FeSt₂ yielded IONPs with a narrow size range (9-15 nm) and nanoplates, while FeSt₃ produced IONPs with a broader size range (6-25 nm) and nanocubes. These studies demonstrate that the structural and compositional differences between FeSt₂ and FeSt₃ (polycation size, carboxylate coordination, free stearic acid content) directly influence the size, shape, and monodispersity of resulting IONPs.
The in vitro synthesis and characterization of iron stearates and their derived IONPs were verified through controlled experiments. Iron stearates were synthesized by mixing iron chloride solutions with sodium stearate at 80°C for 15 minutes, followed by purification and drying. Structural characterizations employed XRD and SAXS to confirm lamellar structures, MALDI-TOF MS to identify polynuclear complexes, and EPR/Mössbauer spectroscopy to determine iron oxidation states (predominantly Fe(III) with minor Fe(II) in fresh FeSt₂). Thermal decomposition was conducted in octylether with oleic acid at 291°C, and IONPs were characterized by TEM, SEM, and magnetic measurements. The nucleation mechanism was proposed to involve decarboxylation-catalyzed reduction of Fe(III) to Fe(II) and condensation of activated polynuclear complexes, with FeSt₃'s larger polycations contributing to higher thermal stability and broader IONP size distribution.

Effect of Iron Stearate Purity on the Shape and Size of Maghemite Nanoparticles

Meftah, Sakina, et al. Colloids and Surfaces A: Physicochemical and Engineering Aspects 680 (2024): 132689

This study investigated the impact of iron stearate purity (commercial as-received, commercial washed, homemade pure) on the shape and size of maghemite (γ-Fe₂O₃) nanoparticles synthesized via thermal decomposition. Three types of iron stearate precursors were used: commercial FeSt₂ (P₁), washed commercial FeSt₂ (P₁ᵂ), commercial FeSt₃ (P₂), washed commercial FeSt₃ (P₂ᵂ), and homemade pure FeSt₃ (P₃). EDS and XRD analyses revealed impurities (sodium stearate (NaSt) and sodium chloride (NaCl)) in commercial precursors, while P₃ was impurity-free. Thermal decomposition with P₁ (NaSt + NaCl) yielded triangular NPs (mean height 9.7 nm, polydispersity 16%); P₁ᵂ (NaSt only) and P₂/P₂ᵂ (NaSt ± residual NaCl) produced cubic NPs (mean side diagonal 10.5-11.7 nm, polydispersity 11-13%); P₃ yielded spherical NPs (mean diameter 6.7 nm, polydispersity 12%). All NPs were pure maghemite as confirmed by SAED and XRD. These studies demonstrate that iron stearate purity (impurity type and content) is a key parameter controlling maghemite NP shape, with NaSt inducing cubic growth and combined NaSt + NaCl enabling triangular growth, while pure precursor yields spherical NPs.
The in vitro synthesis and characterization of maghemite NPs were conducted through controlled experiments. Iron stearate precursors were prepared by aqueous coprecipitation (homemade P₃) or commercial sources (P₁, P₂) with/without washing (4 L ultrapure water to remove NaCl). NPs were synthesized by heating 1.1 mmol iron stearate, 2.2 mmol oleic acid, and 10 mL dioctyl ether at 45°C/min to 287°C, refluxing for 2 h. NPs were characterized by TEM (shape/size), EDS (elemental composition), SAED, and XRD (crystal phase). Impurity identification in precursors confirmed NaSt (XRD peak at 22°) and NaCl (peaks at 31.7° and 45.5°) in commercial samples, which were removed by washing only for NaCl. Shape variation was attributed to selective adsorption of NaSt on {100} facets (cubic growth) and combined Na⁺/Cl⁻ adsorption on specific facets (triangular growth), while pure precursor allowed uniform oleic acid stabilization (spherical growth).

Synthesis, Composition and Spectroscopic Characterization of Iron Stearate Compounds

Abrahamson, Harmon B., et al. Journal of Inorganic Biochemistry 54.2 (1994): 115-130

This study systematically synthesized and characterized iron stearate compounds, focusing on their molecular composition, structure, and physical properties. Three synthetic routes were employed: Route A (reaction of ferrous sulfate with sodium stearate in ethanol/water under air oxidation), Route B (gut model, ferrous sulfate with stearic acid and sodium bicarbonate at physiological temperature/pH), and Route C (ferric citrate with stearic acid and sodium bicarbonate). All routes yielded a trinuclear μ-oxo iron(III) complex with the formula [Fe₃O(St)₆(H₂O)₃]St (St = stearate, C₁₇H₃₅CO₂⁻), confirmed by elemental analysis (C: 67.94-68.25%, H: 11.33-11.34%, Fe: 7.77%). Commercial "ferrous stearate" was identified as a mixed-valence trimer [Fe₂ᵢᵢᵢFeᵢᵢO(St)₆(H₂O)₃], while commercial "ferric stearate" was a mixture of the trimer and free stearic acid. Spectroscopic characterizations (mid/far-IR, ¹H/¹³C NMR) revealed bridging carboxylate coordination (Δν = 117-151 cm⁻¹) and paramagnetism-induced peak broadening. Thermal analysis showed hydrated trimer lost 6.0% weight at 50°C (8 water molecules) and melted at 110-118°C. These studies demonstrate that iron stearates are polynuclear μ-oxo complexes rather than simple mononuclear salts, with commercial products varying in purity and oxidation state.
The in vitro synthesis and characterization of iron stearates were verified through controlled experiments. Syntheses were conducted with stoichiometric ratios of iron salts (ferrous sulfate, ferric citrate) and stearate sources (sodium stearate, stearic acid), with purification via filtration and solvent extraction (ethanol/acetone) to remove excess stearic acid. Physical properties (melting point, solubility) were determined by standard methods. Spectroscopic analyses included mid-IR (4000-450 cm⁻¹, diffuse reflectance) and far-IR (500-100 cm⁻¹, nujol mulls) for carboxylate coordination and metal-oxygen framework vibrations, ¹H/¹³C NMR (300/75 MHz in CDCl₃) for organic chain structure, and TGA/DSC for thermal behavior. Elemental analysis confirmed the trinuclear formula, and spectral subtraction distinguished commercial mixtures from pure trimer. Route B mimicked gastrointestinal conditions, confirming the trimer can form under physiological settings, supporting its potential role in iron absorption.

Iron Stearate as a Pro-Oxidant: Impact on Thermal Degradation Kinetics and Lifetime of PP/PLA Blends Under Artificial Aging

Hayoune, Fouzia, et al. Thermochimica Acta 680 (2020): 178700

This study explored the role of iron stearate (IS, 0.2 wt.%) as a pro-oxidant in 50:50 polypropylene (PP)/polylactic acid (PLA) blends compatibilized with 3 wt.% PP-g-MA, focusing on thermal degradation kinetics and lifetime during artificial aging (70°C for 0, 7, 14, 21 days). Thermogravimetric (TG) analysis confirmed two-stage degradation for all blends: PLA decomposition (first stage, ~300-370°C) and PP decomposition (second stage, ~450-490°C). Incorporation of IS reduced key decomposition temperatures-for unaged blends at 10°C/min, onset temperature dropped from 328.8°C (PP/PLA) to 278.8°C (PP/PLA/IS), and PLA's maximum decomposition temperature fell from 363.5°C to 313.1°C. Kinetic modeling via three isoconversional methods (it-FWO, TAS, VYA/CE) showed IS decreased activation energy (Eₐ): for PLA decomposition, Eₐ of PP/PLA/IS was 19.2-33.1 kJ/mol lower than PP/PLA across aging periods; for PP decomposition, Eₐ was lower in unaged/7-day aged blends but higher in 14/21-day aged blends due to mechanism shifts. IS also altered degradation mechanisms (PLA: random nucleation vs. chemical reaction; PP: diffusion vs. chemical reaction). Lifetime prediction (α=0.3 for PLA decomposition) revealed IS shortened lifetimes by 95.4-99.9% at 25°C, with further reduction by artificial aging-after 21 days, PP/PLA/IS had a lifetime of 0.47 years vs. 85.7 years for PP/PLA. These studies demonstrate that iron stearate accelerates thermal degradation of PP/PLA blends, lowers Eₐ, modifies reaction mechanisms, and drastically reduces service lifetime, with effects amplified by artificial aging.
The in vitro thermal degradation and kinetic analysis were conducted through controlled experiments. PP/PLA and PP/PLA/IS blends were prepared via melt extrusion (190°C, 30 rpm) and compression molding (190°C, 2 min) to form 80-90 µm films. Artificial aging was performed in an oven at 70±0.1°C, with sampling every 7 days. TG measurements were carried out on a Q500 TGA (TA Instruments) under nitrogen flow (50 mL/min) at heating rates of 5, 10, 15, 20, 25°C/min up to 700°C. Conversion (α) was calculated from mass loss, and kinetic parameters (Eₐ, pre-exponential factor A, reaction model) were derived via isoconversional methods. Lifetime was predicted using the equation t = g(α)/(A·exp(-Eₐ/(RT))) at various failure temperatures. Mechanism identification involved fitting TG data to solid-state reaction models, confirming IS-induced transitions from chemical reaction to nucleation/diffusion-controlled degradation. All experiments were replicated to ensure reproducibility, with consistent trends of Eₐ reduction and lifetime shortening observed for PP/PLA/IS blends across aging periods.

Custom Q&A

What is the molecular formula of Iron stearate?

The molecular formula of Iron stearate is C54H105FeO6.

What are the synonyms for Iron stearate?

The synonyms for Iron stearate are Ferric stearate, 555-36-2, Iron(III) Stearate, and Iron Tristearate.

What is the molecular weight of Iron stearate?

The molecular weight of Iron stearate is 906.3 g/mol.

What is the IUPAC Name of Iron stearate?

The IUPAC Name of Iron stearate is iron(3+);octadecanoate.

What is the InChI of Iron stearate?

The InChI of Iron stearate is InChI=1S/3C18H36O2.Fe/c3*1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20;/h3*2-17H2,1H3,(H,19,20);/q;;;+3/p-3.

What is the InChIKey of Iron stearate?

The InChIKey of Iron stearate is XHQSLVIGPHXVAK-UHFFFAOYSA-K.

What is the Canonical SMILES of Iron stearate?

The Canonical SMILES of Iron stearate is CCCCCCCCCCCCCCCCCC(=O)[O-].CCCCCCCCCCCCCCCCC(=O)[O-].CCCCCCCCCCCCCCCCC(=O)[O-].[Fe+3].

What is the CAS number of Iron stearate?

The CAS number of Iron stearate is 555-36-2.

What is the European Community (EC) Number of Iron stearate?

The European Community (EC) Number of Iron stearate is 209-095-5.

What are some physical properties of Iron stearate?

Some physical properties of Iron stearate include a molecular weight of 906.3 g/mol, a hydrogen bond acceptor count of 6, and a topological polar surface area of 120Ų.