30525-89-4

Usage

Uses

Used in Fumigation and Disinfection:
Paraformaldehyde is used as a fumigant and disinfectant due to its ability to generate formaldehyde gas during heating, which has antimicrobial properties.
Used in Manufacturing Synthetic Resins:
Paraformaldehyde is used in the manufacture of synthetic resins such as melamine resin, phenol resin, and polyacetal resin. It serves as a source of either gaseous formaldehyde or solution formaldehyde for these applications.
Used in Cell Culture:
Paraformaldehyde is used in cell culture as a fixative, which helps preserve the structure and morphology of cells for further analysis.
Used as a Fixative in Electron Microscopy:
Paraformaldehyde serves as a fixative in electron microscopy, allowing for the preservation of cellular structures at a high resolution.
Used in the Preparation of Formalin Fixatives for Tissues or Cells:
Paraformaldehyde is used in the preparation of formalin fixatives for tissues or cells, which helps maintain the integrity of the samples for histological examination.
Used in Fungicides and Bactericides:
Paraformaldehyde is used in fungicides and bactericides, providing antimicrobial activity to protect against various microorganisms.
Used in the Manufacture of Adhesives:
Paraformaldehyde is used in the production of adhesives, where its ability to generate formaldehyde gas during heating aids in the curing process.
Used in Root Canal Sealers:
Paraformaldehyde is used in root canal sealers, providing antimicrobial activity to help prevent infection and promote healing.
Used in Tissue Fixation Solutions:
4% Paraformaldehyde tissue fixation solution is widely used in the detection of tissue, tissue slice, cell, and other biological sample fixation solutions such as immunohistochemistry (IHC), immunofluorescence (IF), immunocytochemistry (IC), and flow cytometry (FACS).

Characteristics

Paraformaldehyde is the smallest solid form of liquid formaldehyde, formed by the polymerization of formaldehyde with a typical degree of polymerization of 8-100 units. As paraformaldehyde is basically a condensed form of formaldehyde, it possesses the common characteristics with a wide range of applications.Paraformaldehyde does not need to be dissolved in water in order to take part in a chemical reaction.Use of paraformaldehyde is convenient and safe. It avoids pollution arising from the disposal of the distillate obtained in the thermosetting resin production which is contaminated with organic matter.Paraformaldehyde made with very low acid content in a chemical resistant environment can prevent the formation of acidic by-products.

Preparation

Paraformaldehyde [30525-89-4] was first produced in 1859. This polymer, at first mistakenly called dioxymethylene and trioxymethylene, consists of a mixture of poly(oxymethylene) glycols HO-(CH2O)n-H with n=8-100. The formaldehyde content varies between 90 and 99 % depending on the degree of polymerization n (the remainder is bound or free water). It is an industrially important linear polyoxymethylene.Paraformaldehyde is prepared industrially in continuously operated plants by concentrating aqueous formaldehyde solutions under vacuum conditions. At first, colloidal, waxy gels are obtained, which later become brittle. The use of a fractionating column through which gases were passed dates from about 1925.Paraformaldehyde is currently produced in several steps which are carried out at low pressure and various temperatures. Highly reactive formaldehyde is produced under vacuum conditions starting with solutions that contain 50-100 ppm of formic acid and also 1-15 ppm of metal formates where the metals have an atomic number of 23-30 (e.g., Mn, Co, and Cu). The solutions are processed in thin-layer evaporators and spray dryers.

Air & Water Reactions

Flammable. Forms aqueous solution of formaldehyde, often quite slowly.

Reactivity Profile

Paraformaldehyde may react violently with strong oxidizing agents (hydrogen peroxide, performic acid, perchloric acid in the presence of aniline, potassium permanganate, nitromethane). May react with bases (sodium hydroxide, potassium hydroxide, ammonia), and with nitrogen dioxide (explosive reaction around 180°C). Reacts with hydrochloric acid to form highly toxic bis(chloromethyl) ether. Polymerization reaction with phenol may develop sudden destructive pressure [Bretherick, 5th ed., 1995, p.168]. May generate flammable and/or toxic gases in combination with azo, diazo compounds, dithiocarbamates, nitrides, and strong reducing agents. Generates toxic formaldehyde gas when heated. Can react with air to give first peroxo acids, and ultimately formic acid. These reactions are activated by light, catalyzed by salts of transition metals, and are autocatalytic (catalyzed by the products of the reaction). Incompatible with liquid oxygen.

Health Hazard

Vapor or dust irritates eyes, mucous membranes, and skin; may cause dermatitis. Ingestion of solid or of a solution in water irritates mouth, throat, and stomach and may cause death.

Fire Hazard

Behavior in Fire: Changes to formaldehyde gas, which is highly flammable.

Safety Profile

Moderately toxic by ingestion. A severe eye and skin irritant. Mutation data reported. Flammable when exposed to heat or flame; can react with oxidzing materials. To fight fire, use alcohol foam, COr, dry chemical. Incompatible with liquid oxygen. Dangerous; when heated to decomposition it emits toxic formaldehyde gas. See also FORMALDEHYDE.

InChI:InChI=1/C3H8O/c1-3-4-2/h3H2,1-2H3

Upstream product

• 75-21-8 oxirane 
• 74-85-1 ethene 
• 71-43-2 benzene 
• 186581-53-3 diazomethane 
• 98279-57-3 (4-oxo-4H-[1]pyridyloxy)-acetic acid 
• 60-29-7 diethyl ether 
• 6245-99-4 2,2-dimethyl-oxetane 
• 646-06-0 1,3-DIOXOLANE 
• 110-86-1 pyridine 
• 108-01-0 2-(N,N-dimethylamino)ethanol 
• 94-36-0 dibenzoyl peroxide 
• 996-35-0 N,N-dimethylisopropyl amine 
• 616-39-7 N,N-diethylnmethylamine 
• 927-62-8 N,N-dimethylbutylamine 

Downstream Products

• 38455-24-2 Methylen-bis-azetidin 
• 104587-62-4 azetidin-2-ylmethanol 
• 3970-17-0 chloromethyl δ-chlorobutyl ether 
• 34520-27-9 bis(4-chlorobutoxy)methane 
• 100617-78-5 4,5-Dimethyl-2-pyrrolidinomethyl-phenol 
• 124514-35-8 bis-(5-tert-butyl-4-hydroxy-2-methyl-3-pyrrolidinomethyl-phenyl)-sulfide 
• 69084-02-2 4-bromo-2-pyrrolidinomethyl-phenol 
• 101263-50-7 4-chloro-3,5-dimethyl-2-pyrrolidinomethyl-phenol 
• 102886-32-8 bis-(5-chloro-2-hydroxy-3-pyrrolidinomethyl-phenyl)-methane 
• 66839-97-2 3-Pyrrolidinomethyl-biphenyl-4-ol 
• 124141-44-2 2,2-bis-(4-hydroxy-3-methyl-5-pyrrolidinomethyl-phenyl)-propane 
• 102557-52-8 bis-(5-chloro-2-hydroxy-3-pyrrolidinomethyl-phenyl)-sulfide 
• 6300-54-5 6-Chlor-2-pyrrolidinomethyl-thymol 
• 116282-91-8 2,2-bis-(4-hydroxy-3-isopropyl-5-pyrrolidinomethyl-phenyl)-propane 

Relevant academic research and scientific papers

Oxathiirane

We describe the first preparation of the long-sought parent oxathiirane from sulfine through photochemical rearrangement with light at λ = 313 ± 10 nm in an Ar matrix at 11 K. Oxathiirane was characterized by the extraordinarily good agreement of experime

Hexagonal Orthovanadates as Catalysts in the Oxidation of Methanol to Formaldehyde

Improved selectivities are obtained in the catalytic oxidation of methanol to formaldehyde using hexagonal orthovanadates of the type Sr3-xLa2x/3(VO4)2 (x=0.3-1.5) in comparison with those using the strontium and lanthanum orthovanadates separately.

Selective Photooxidation of Light Alkanes to Oxygenates using Supported Molybdenum Oxide Catalysts

Photo-assisted catalytic partial oxidation of methane, ethane and propane has been performed in the presence of supported molybdenum oxide catalysts at around 500 K by the use of a fluidized bed flow-type reactor under UV irradiation.Temperatures as high as 500 K were indispensable for the selective formation of methanal from methane (ca. 19 μmol h-1), corresponding to 5.5percent of the photons irradiated into the catalyst bed (-1) at elevated temperature.The reaction seemed to proceed via charge-transfer complexes formed by photo-activation of terminal coordinatively unsaturated M=O groups in multilayers of molybdenum species.

Kinetics and mechanism of the reaction of CH3O with NO

The kinetics of the reaction of CH3O with NO and the branching ratio for HCHO product formation, obtained as ΓHCHO = (Rate of HCHO formation) / (Rate of CH3O decay), have been studied using a discharge flow reactor. Laser induced fluorescence has been used to monitor the decay of the CH3O radical and the build-up of the HCHO product. Overall rate constants and product branching ratios were measured at room temperature over the pressure range of 0.72-8.5 torr He. Three reaction mechanisms were considered which differed in the routes of HCHO formation: (i) direct disproportionation; (ii) via an energized collision complex; or (iii) both reaction routes. It has been shown that data on the pressure dependence of the overall rate constant are not sufficient to distinguish between these mechanisms. In addition, an accurate value of ΓHCHO∞ is required. Analysis of the available experimental data provided 0.0 and about 0.1 as the lower and upper limit for ΓHCHO∞, respectively. Since the rate constants derived for CH3ONO formation were not sensitive to the value assumed for ΓHCHO∞, kCH(3)ONO0 = (1.69 ± 0.69) × 10-29 cm6 molecule-2 s-1 and kCH(3)ONO∞ = (2.45 ± 0.31) × 10-11 cm3 molecule-1 s-1 could be derived. The rate constant obtained for formaldehyde formation when extrapolated to zero pressure is kHCHO0 = (3.15 ± 0.92) × 10-12 cm3 molecule-1 s-1.

Kinetics and Mechanism of Methanol Oxidation in Supercritical Water

We oxidized methanol in supercritical water at 246 atm and temperatures between 500 and 589 deg C.Pseudo-first-order rate constants calculated from the data led to Arrhenius parameters of A = 1021.3 +/- 5.3 s-1 and Ea = 78 +/- 20 kcal/mol.The induction time for methanol oxidation decreased from 0.54 s at 525 deg C to 0.093 s at 585 deg C and the reaction products were formaldehyde, CO, and CO2.Formaldehyde was a primary product, while CO and CO2 were secondary products.Formaldehyde was more reactive than methanol and its yield was always less than 24percent.The temporal variation of the CO yield exhibited a maximum, whereas the CO2 yield increased monotonically.The experimental data were consistent with a set of consecutive reactions (CH3OH -> CH2O -> CO -> CO2) with pseudo-first-order global kinetics.The experimental data were also used to validate a detailed chemical kinetics model for methanol oxidation in supercritical water.With no adjustments, this elementary reaction model quantitatively predicts the product distribution as a function of the methanol conversion, and it accurately predicts that this distribution is nearly independent of temperature.A sensitivity analysis revealed that only eight elementary reaction steps most strongly influenced the calculated species' concentrations.A reaction path analysis showed that the fastest reactions that consumed methanol involved OH attack and the resulting radicals produced formaldehyde, which was attacked by OH to form, eventually, CO.The CO was then oxidized to CO2 via rection with OH.This work shows that the chemistry for methanol oxidation in supercritical water at temperatures around 500-600 deg C is quantitatively analogous to combustion chemistry within the same temperature range.

Improved anticonvulsant activity of phenytoin by a redox brain delivery system II: Stability in buffers and biological materials

The stability of nine chemical delivery systems (CDSs) for phenytoin (DPH) was studied in aqueous buffers and in biological materials. The systems were based on a dihydropyridune ? quaternary pyridinium salt redox pair attached to 3-(hydroxymethyl)phenytoin via an ester linkage. The pyridinium derivatives released DPH in aqueous buffers and their hydrolytic reactivity was consistent with their chemical structure. Although in rat blood and plasma all pyridinium esters hydrolyzed rapidly, there was a wide range in the hydrolysis rates in rat brain homogenate. The sterically hindered 1-alkylcarboxynicotinamide was the least reactive ester (t( 1/2 ) = 98.2 min), while the trigonellylglycolate ester was the fastest to hydrolyze enzymatically (t( 1/2 ) = 2 min) in rat brain homogenate. In acidic media, the major products of all dihydropyridine esters were the corresponding water adducts, the 6-hydroxy-1,4,5,6-tetrahydropyridines. These adducts were of no significance in biological materials. After comparison of the relative stability of the corresponding pairs of dihydropyridine and pyridinium ion in brain homogenate and the absolute stability of the various dihydropyridines, two CDSs were chosen for further in vivo evaluations. The CDSs chosen were the dihydrotrigonellinate ester and its 6-methyl derivative.

Oxidative degradation of norfloxacin by a lipophilic oxidant, cetyltrimethylammonium permanganate in water-acetonitrile medium: A kinetic and mechanistic study

The present study reports the oxidative metabolism of an established antibacterial drug norfloxacin (NRF) by a lipid compatible lipophilic Mn(VII) oxidant, cetyltrimethylammonium permanganate (CTAP) in acetonitrile-water binary mixture in the presence of acetic acid. The metabolized products are identified as 7-amino-1-ethyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, formaldehyde, and ammonia. The kinetics of the reaction is studied in aqueous acetonitrile media in the presence of acetic acid by UV-vis spectroscopic method by monitoring the absorbance of Mn(VII) at 530 nm under pseudo first-order condition. The reaction is found to be first-order with respect to CTAP and fractional order with respect to norfloxacin and acetic acid. Occurrence of Michaelis-Menten type kinetics with respect to norfloxacin confirmed the binding of oxidant and substrate to form a complex before the rate determining step. A suitable ionic mechanism is proposed based on the experimental findings. The proposed reaction mechanism is supported by the effect of solvent polarity and effect of temperature on the reaction rate. High negative entropy of activation (ΔS≠ = - 259 to - 158 J K- 1 mol- 1) supported the existence of a forced, more ordered and extensively solvated transition state. Further, solvent polarity-reactivity relationship revealed (i) the presence of less polar transition state compared to the reactants, (ii) differential contribution from dipolar aprotic (acetonitrile) and polar protic (water) solvents toward the reaction process through specific and nonspecific solute-solvent interaction and (iii) presence of intramolecular H-bonding in oxidant-substrate complex in acetonitrile rich domain and intermolecular H-bonding between oxidant-substrate complex and water in water rich domain.

The ethene-ozone reaction in the gas phase

The ethene-ozone reaction was investigated in a 570 L spherical glass reactor at atmospheric pressure, using long-path FTIR spectroscopy for detection of the individual products. Experiments were performed in the presence of hydroxy and carbonyl compounds to identify the reactions of the Criegee intermediate CH2OO formed in ethene ozonolysis. Using 13C-labeled HCHO, this reaction was found to proceed via an unstable cyclic adduct which decays to the detected products HCHO, HCOOH and CO. [CH2OO + HCHO → HCHO + HCOOH (eq 13); CH2OO + HCHO → HCHO + CO + H2O (eq 14a); CH2OO + HCHO → HCHO + HCO + OH (eq 14b)] The relative rates of the reactions of CH2OO with HCOOH and HCHO were determined from the product analysis. In addition, evidence was found that the reaction of CH3CHO with the CH2OO intermediate does not exclusively produce secondary propene ozonide, but also HCHO and CO2. The results of this study have been combined with data from previous investigations to give a complete description of the gas phase ozonolysis of ethene and are discussed in comparison with ozonolysis reactions occurring in the liquid phase.

Elucidation of the 1,4-dioxane decomposition pathway at discrete ultrasonic frequencies

The sonolytic decomposition chemistry of the refractory compound 1,4-dioxane in aqueous solution has been investigated at four ultrasonic frequencies (205, 358, 618, and 1071 kHz). To maintain fully saturated solutions, argon and oxygen were used as sparge gases. Using a frequency of 358 kHz, the observed first-order kinetic rate constants for 1,4-dioxane destruction were highest with a sparge gas ratio of 75% Ar/25% O2 (k = 4.32 ± 0.31 x 10-4 s-1) and lowest in the presence of pure argon (k= 8.67 ± 0.47 x 10-5 s-1). Ethylene glycol diformate, methoxyacetic acid, formaldehyde, glycolic acid, and formic acid were found to be the major intermediates of 1,4-dioxane degradation. A reaction mechanism involving these byproducts was proposed concerning primarily reactions with oxidizing species (·OH, ·OOH, ·O) in and near the interfacial region of the cavitation bubble. The highest observed first-order 1,4-dioxane decomposition rate occurred at 358 followed by 618, 1071, and 205 kHz. At each frequency, approximately 85% of the initial carbon is accounted for as the parent compound, as an intermediate, or as CO2. The major byproducts formation was investigated at all four frequencies, and the results indicate that free radical mechanisms are significant over the entire range of frequencies studied. The sonolytic decomposition chemistry of the refractory compound 1,4-dioxane in aqueous solution has been investigated at four ultrasonic frequencies (205, 358, 618, and 1071 kHz). To maintain fully saturated solutions, argon and oxygen were used as sparge gases. Using a frequency of 358 kHz, the observed first-order kinetic rate constants for 1,4-dioxane destruction were highest with a sparge gas ratio of 75% Ar/25% O2 (k = 4.32 ± 0.31 × 10-4 s-1) and lowest in the presence of pure argon (k = 8.67 ± 0.47 × 10-5 s-1). Ethylene glycol diformate, methoxyacetic acid, formaldehyde, glycolic acid, and formic acid were found to be the major intermediates of 1,4-dioxane degradation. A reaction mechanism involving these byproducts was proposed concerning primarily reactions with oxidizing species (·OH, ·OOH, ·O) in and near the interfacial region of the cavitation bubble. The highest observed first-order 1,4-dioxane decomposition rate occurred at 358 followed by 618, 1071, and 205 kHz. At each frequency, approximately 85% of the initial carbon is accounted for as the parent compound, as an intermediate, or as CO2. The major byproducts formation was investigated at all four frequencies, and the results indicate that free radical mechanisms are significant over the entire range of frequencies studied.

Quantitative measurements of HO2 and other products of n -butane oxidation (H2O2, H2O, CH2O, and C2H4) at elevated temperatures by direct coupling of a jet-stirred reactor with sampling nozzle and cavity ring-down spectroscopy (cw-CRDS)

For the first time quantitative measurements of the hydroperoxyl radical (HO2) in a jet-stirred reactor were performed thanks to a new experimental setup involving fast sampling and near-infrared cavity ring-down spectroscopy at low pressure. The experiments were performed at atmospheric pressure and over a range of temperatures (550-900 K) with n-butane, the simplest hydrocarbon fuel exhibiting cool flame oxidation chemistry which represents a key process for the auto-ignition in internal combustion engines. The same technique was also used to measure H2O2, H2O, CH2O, and C2H4 under the same conditions. This new setup brings new scientific horizons for characterizing complex reactive systems at elevated temperatures. Measuring HO2 formation from hydrocarbon oxidation is extremely important in determining the propensity of a fuel to follow chain-termination pathways from R + O2 compared to chain branching (leading to OH), helping to constrain and better validate detailed chemical kinetics models.