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CAS Number:8017-16-1
EC Number:232-417-0
Polyphosphoric acid= Tetraphosphoric acid
General description
Polyphosphoric acid is a hygroscopic, clear and viscous liquid.
Polyphosphoric acid has been synthesized by reacting phosphoric acid with phosphorus (V) oxide.
Polyphosphoric acid is a moderately strong mineral acid with a wide range of applications.
PPA may be used in bone regeneration by treating titanium (Ti) implants.
Application
Polyphosphoric acid may be used in the following processes:
Functionalize mesoporous silica–polymer nanocomposites (SBA/PS).
Polyphosphoric acid a catalyst in the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones.
Polyphosphoric acid a dehydrating agent and phosphorus source in the synthesis of Si, P co-doped carbon (SiPDC) materials.
Polyphosphoric acid a catalyst and absorbent of ammonia during the synthesis of dimethyl carbonate (DMC).
Polyphosphoric acid a solvent in the synthesis of hyperbranched polybenzoxazoles (HBPBOs).
Packaging
100 mL in poly bottle
1 L in poly bottle
PPA105 is miscible with water, hydrolyzing into ortho-phosphoric acid.
Reaction is exothermic and demands due care.
General description
Polyphosphoric acid (PPA) is widely employed as acylation and alkylation reagent in various reactions.
Polyphosphoric acid is a strong mineral acid with excellent dehydrating properties.
Application
Polyphosphoric acid may be used in the synthesis of aromatic sulfones, N-substituted amides and 4-aminobenzophenones.
Polyphosphoric acid may also be used in dehydration, Fischer-Indole Synthesis, Beckmann Rearrangement and Schmidt Rearrangement reactions.
Polyphosphoric acid can be used as a catalyst in the synthesis of various aromatic ketones.
PPA may be used as a catalyst during the synthesis of dimethyl carbonate (DMC) from urea and methanol.
Polyphosphoric acid also acts as an absorbent for the ammonia generated in the process.
PPA may be used to prepare silica-supported polyphosphoric acid (PPA-SiO2), an easy to handle, reusable heterogenous catalyst.
Packaging
100 g in poly bottle
25 g in glass bottle
1 kg in poly bottle
Other Notes
We are committed to bringing you Greener Alternative Products, which adhere to one or more of The 12 Principles of Greener Chemistry.
This product has been enhanced for energy efficiency.
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A phosphoric acid, in the general sense, is a phosphorus oxoacid in which each phosphorus atom is in the oxidation state +5, and is bonded to four oxygen atoms, one of them through a double bond, arranged as the corners of a tetrahedron.
Two or more of these PO4 tetrahedra may be connected by shared single-bonded oxygens, forming linear or branched chains, cycles, or more complex structures.
Polyphosphoric acid single-bonded oxygen atoms that are not shared are completed with acidic hydrogen atoms.
The general formula of a phosphoric acid is Hn+2−2xPnO3n+1−x, where n is the number of phosphorus atoms and x is the number of fundamental cycles in the molecule's structure, between 0 and (n+2)/2.
Synonyms
Condensed phosphoric acid
EC 232-417-0
EINECS 232-417-0
HSDB 1176
Phospholeum
Polyphosphoric acid
Polyphosphoric acids
Superphosphoric acid
Tetraphosphoric acid
Trimethyl orthophosphate.
Removal of protons (H+ ) from k hydroxyl groups –OH leaves anions generically called phosphates (if k = n−2x+2) or hydrogen phosphates (if k is between 1 and n−2x+1), with general formula [Hn−2x+2−kPnO3n+1−x]k−.
The fully dissociated anion (k = n−2x+2) has formula [PnO3n−x+1](n−2x+2)− is The term is also used in organic chemistry for the functional groups that result when or more of the hydrogens are replaced by bonds to other groups.
These acids, together with their salts and esters, include some of the best-known compounds of phosphorus, of high importance in biochemistry, mineralogy, agriculture, pharmacy, chemical industry, and chemical research.
Chemical Name: Polyphosphoric Acid (PPA)
Synonyms: Phospholeum, Tetraphosphoric Acid, Superphosphoric Acid
Chemical Formula: H(n+2)P(n)O(3n+1)
CAS Number: 8017-16-1
EC Number: 232-417-0
Dehydrating Agent – Polyphosphoric acid is used as a strong drying and dehydrating agent.
Organic Synthesis – Polyphosphoric Acid (PPA) is used to make phosphate esters, acid phosphates and pharmaceuticals.
Polyphosphoric acid is a good ring closing reagent.
Solvent – Polyphosphoric acid can be used as a reaction medium and solvent.
Miscellaneous – PPA is used in metal treatment and as an asphalt and bitumen additive.
Polyphosphoric acid (PPA) has been used in 3.5% to 14% of the asphalt placed in the United States over the past 5 years.
Polyphosphoric acid represents up to 400 million tons of hot mix.
As with all other components of the mix, testing is required to demonstrate the performance of PPA with each formulation of asphalt and aggregate, together with polymer, antistrip agents, and other additives that may be used.
Results of the following tests are presented: dynamic shear rheometer, Hamburg, Lottman, and multiple stress creep and recovery tests on a matrix of a common asphalt with aggregate, three antistrip agents, two types of polymers, and PPA.
Laboratory data for the materials tested show that the performance of PPA-modified asphalt can be improved with the addition of antistrip agents such as a phosphate ester, a particular polyamine compound, and hydrated lime.
These findings hold true for cases where modification includes the use of polymers: styrene–butadiene–styrene and Elvaloy.
Acids
Orthophosphoric acid
Main article: Phosphoric acid
Polyphosphoric acid simplest and most commonly encountered of the phosphoric acids is orthophosphoric acid, H3PO4.
Indeed, the term phosphoric acid often means this compound specifically (and this is also the current IUPAC nomenclature).
Oligophosphoric and polyphosphoric acids
Polyphosphoric acid
Two or more orthophosphoric acid molecules can be joined by condensation into larger molecules by elimination of water.
Condensation of a few units yields the oligophosphoric acids, while larger molecules are called polyphosphoric acids.
(However, the distinction between the two terms is not well defined.)
For example, pyrophosphoric, triphosphoric and tetraphosphoric acids can be obtained by the reactions
2 H3PO4 → H4P2O7 + H2O
H4P2O7 + H3PO4 → H5P3O10 + H2O
H5P3O10 + H3PO4 → H6P4O13 + H2O
Polyphosphoric acid "backbone" of a polyphosphoric acid molecule is a chain of alternating P and O atoms.
Each extra orthophosphoric unit that is condensed adds 1 extra H (hydrogen) atom, 1 extra P (phosphorus) atom, and 3 extra O (oxygen) atoms. The general formula of a polyphosphoric acid is Hn+2PnO3n+1 or HO(–P(O)(OH)–O–)nH.
Polyphosphoric acids are used in organic synthesis for cyclizations and acylations.
Cyclic phosphoric acids
Condensation between two –OH units of the same molecule, on the other hand, eliminates two hydrogen atoms and one oxygen atom, creating a cycle, as in the formation of trimetaphosphoric acid: H5P3O10 → H3P3O9 + H2O
Polyphosphoric acid general formula of a phosphoric acid is Hn−2x+2PnO3n−x+1, where n is the number of phosphorus atoms and x is the number of fundamental cycles in the molecule's structure; that is, the minimum number of bonds that would have to be broken to eliminate all cycles.
The limiting case of internal condensation, where all oxygen atoms are shared and there are no hydrogen atoms (x = (n+2)/2) would be an anhydride PnO5n/2, such as phosphorus pentoxide P4O10.
Phosphates
Removal of the hydrogen atoms as protons H+ turns a phosphoric acid into a phosphate anion. Partial removal yields various hydrogen phosphate anions.
Orthophosphate
Main article: Phosphate
Polyphosphoric acid anions of orthophosphoric acid H3PO4 are orthophosphate PO3−4, hydrogen phosphate HPO2−4, and dihydrogen phosphate H2PO−4
Linear oligophosphates and polyphosphates
Main article: Polyphosphate
Dissociation of pyrophosphoric acid H4P2O7 generates four anions, H4-kP2O−7k−, where the charge k ranges from 1 to 4.
Polyphosphoric acid last one is pyrophosphate [P2O4−7. The pyrophosphates are mostly water-soluble.
Likewise, tripolyphosphoric acid H5P3O10 yields at least five anions [H5-kP3O10]k−, where k ranges from 1 to 5, including tripolyphosphate [P3O5−10. Tetrapolyphosphoric acid H6P4O13 yields at least six anions, including tetrapolyphosphate [P4O6−13, and so on. Note that each extra phosphoric unit adds one extra P atom, three extra oxygen atoms, and either one extra hydrogen atom or an extra negative charge.
Branched polyphosphoric acids give similarly branched polyphosphate anions.
The simplest example of this is triphosphono phosphate [OP(OPO3)3]9− and its partially dissociated versions.
Polyphosphoric acid general formula for such (non-cyclic) polyphosphate anions, linear or branched, is [Hn+2−kPnO3n+1]k−, where the charge k may vary from 1 to n+2.
Generally in an aqueous solution, the degree or percentage of dissociation depends on the pH of the solution.
Cyclic polyphosphates
Trimetaphsphoric acid
Polyphosphoric acid phosphoric acid units can be bonded together in rings (cyclic structures) forming metaphosphoric acid molecules.
Polyphosphoric acid simplest such compound is trimetaphosphoric acid or cyclo-triphosphoric acid having the formula H3P3O9.
Polyphosphoric acid structure is shown in the illustration.
Since the ends are condensed, its formula has one less H2O (water) than tripolyphosphoric acid.
What are commonly called trimetaphosphates actually have a mixture of ring sizes.
A general formula for such cyclic compounds is (HPO3)x where x = number of phosphoric units in the molecule.
The hypothetical monomer monometaphosphoric acid (HPO3), which would be valence isoelectronic with nitric acid, is not known to exist.
When these metaphosphoric acids lose their hydrogens as H+, cyclic anions called metaphosphates are formed.
An example of a compound with such an anion is sodium hexametaphosphate (Na6P6O18), used as a sequestrant and a food additive.
Chemical properties
Solubility
These phosphoric acids series are generally water-soluble considering the polarity of the molecules.
Ammonium and alkali phosphates are also quite soluble in water.
The alkaline earth salts start becoming less soluble and phosphate salts of various other metals are even less soluble.
Hydrolysis and condensation
Polyphosphoric acid aqueous solutions (solutions of water), water gradually (over the course of hours) hydrolyzes polyphosphates into smaller phosphates and finally into ortho-phosphate, given enough water.
Higher temperature or acidic conditions can speed up the hydrolysis reactions considerably.
Conversely, polyphosphoric acids or polyphosphates are often formed by dehydrating a phosphoric acid solution; in other words, removing water from it often by heating and evaporating the water off.
Uses
Ortho-, pyro-, and tripolyphosphate compounds have been commonly used in detergents (i. e. cleaners) formulations.
For example, see Sodium tripolyphosphate.
Sometimes pyrophosphate, tripolyphosphate, tetrapolyphosphate, etc. are called diphosphate, triphosphate, tetraphosphate, etc., especially when they are part of phosphate esters in biochemistry. They are also used for scale and corrosion control by potable water providers.
As a corrosion inhibitor, polyphosphates work by forming a protective film on the interior surface of pipes.
Phosphate esters
General chemical structure of a monophosphate ester; here any R can be H or some organic radical.
Polyphosphoric acid -OH groups in phosphoric acids can also condense with the hydroxyl groups of alcohols to form phosphate esters.
Since orthophosphoric acid has three -OH groups, it can esterify with one, two, or three alcohol molecules to form a mono-, di-, or triester. See the general structure image of an ortho- (or mono-) phosphate ester below on the left, where any of the R groups can be a hydrogen or an organic radical.
Di- and tripoly- (or tri-) phosphate esters, etc. are also possible.
Any -OH groups on the phosphates in these ester molecules may lose H+ ions to form anions, again depending on the pH in a solution.
In the biochemistry of living organisms, there are many kinds of (mono)phosphate, diphosphate, and triphosphate compounds (essentially esters), many of which play a significant role in metabolism such as adenosine diphosphate (ADP) and triphosphate (ATP).
Structure of a chiral phosphoric acid derived from BINOL.
See also
Adenosine monophosphate
Adenosine diphosphate
Adenosine triphosphate
Adenosine tetraphosphate
Nucleoside triphosphate
Organophosphate
Phosphonic acid
Phosphoramidate
Ribonucleoside monophosphate
Superphosphate
CAS number 8017-16-1
EC number 232-417-0
Chemical formula HO[P(OH)(O)O](n)H
HS Code 2809 20 00
Quality Level MQ200
Applications
Application Polyphosphoric acid for synthesis.
CAS 8017-16-1, pH (H₂O, 20 °C) acidic,Hydrolysis.
Chemical Formula HOP(OH)(O)O(n)H.
Physicochemical Information
Boiling point 530 °C (1013 hPa)
Density 2.06 g/cm3 (20 °C)
Melting Point -20 °C
Vapor pressure 2 hPa (20 °C)
Hazard Statement(s) H290: May be corrosive to metals.
H314: Causes severe skin burns and eye damage.
Precautionary Statement(s) P234: Keep only in original packaging.
P280: Wear protective gloves/ protective clothing/ eye protection/ face protection/ hearing protection.
P301 + P330 + P331: IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.
P303 + P361 + P353: IF ON SKIN (or hair): Take off immediately all contaminated clothing.
Rinse skin with water.
P304 + P340 + P310: IF INHALED: Remove person to fresh air and keep comfortable for breathing.
Immediately call a POISON CENTER/doctor.
P305 + P351 + P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
Signal Word Danger
Storage class 8B Non-combustible, corrosive hazardous materials
WGK WGK 1 slightly hazardous to water
Disposal 12
Inorganic acids and anhydrides thereof should first be diluted or hydrolyzed by stirring carefully into ice water and then neutralized (protective gloves, fume cupboard!) with sodium hydroxide solution (Cat. No. 105587).
Before filling into container D, check the pH with pH universal indicator strips (Cat. No. 109535).
Fuming sulfuric acid should be carefully stirred dropwise into 40 % sulfuric acid (Cat. No. 109286).
Ensure that plenty of ice is available for cooling!
When sufficiently cool, treat the highly concentrated sulfuric acid as described above.
Analogous to this procedure, other anhydrides can be converted into their corresponding acids.
Acid gases (e.g. hydrogen halide, chlorine, phosgene, sulfur dioxide) can be introduced into dilute sodium hydroxide solution and after neutralization disposed of in container D.
Polyphosphoric acids are odourless, high viscousity liquids with strong hygroscopic properties.
Phosphoric acids with < 95% H3PO4 (68% P2O5) contain the simple orthophosphoric acid.
At higher concentrations the acid consists of a mixture of ortho, pyro, tri, tetra and highly condensed phosphoric acids.
For this reason acids with a concentration > 68% P2O5 are commonly known as polyphosphoric acids.
Polyphosphoric acids are miscible with water, hydrolysing to orthophosphoric acid with the generation of heat.
Polyphosphoric acid are insoluble in hydrocarbons and halogenated hydrocarbons.
Benefits
Wide variety of applications as a reagent in the chemical industry
Powerful dehydrating agent for organic synthesis
Intermediate for production of phosphate esters with high mono-ester content
Safety
For regulatory details such as the classification and labelling as dangerous substances or goods please refer to our corresponding Material Safety Data Sheet.
As stated in the safety data sheet of the substance the use “industrial manufacture of screening smoke ammunition or smoke payloads” is advised against within the EU according to the REACH regulation.
Therefore, every manufacturer of smoke ammunition or smoke payloads is obliged to create a chemical safety assessment for these uses and to inform the ECHA accordingly.
A polymerized phosphorus oxoacid of general formula HO[PO2OH]nH formed by condensation of orthophosphoric acid molecules and containing a backbone chain consisting of alternating P and O atoms covalently bonded together.
Bitumen finds great use in paving and roofing applications.
To enhance or extend its performance, it is often modified with a polymer, including polyphosphoric acid (PPA).
PPA is a reactive oligomer, a short-chain polymer, whose reaction with bitumen is poorly understood.
Polyphosphoric acid an effort to better understand their reaction, the chemical characteristics of PPA and bitumen are reviewed.
Polyphosphoric acid is concluded that PPA cannot dissociate and react with bitumen unless enclaves of high dielectric constant exist in bitumen.
Chitosan nanoparticles (NPs) are widely studied as vehicles for drug, protein, and gene delivery.
However, lack of sufficient stability, particularly under physiological conditions, render chitosan NPs of limited pharmaceutical utility.
The aim of this study is to produce stable chitosan NPs suitable for drug delivery applications.
Chitosan was first grafted to phthalic or phenylsuccinic acids.
Subsequently, polyphosphoric acid (PPA), hexametaphosphate (HMP), or tripolyphosphate (TPP) were used to achieve tandem ionotropic/covalently crosslinked chitosan NPs in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC).
Thermal and infrared traits confirmed phosphoramide bonds formation tying chitosan with the polyphosphate crosslinkers within NPs matrices.
DLS and TEM size analysis indicated spherical NPs with size range of 120 to 350 nm.
Polyphosphoric acid generated NPs exhibited excellent stabilities under harsh pH, CaCl2, and 10% FBS conditions.
Interestingly, DLS, NPs stability and infrared data suggest HMP to reside within NPs cores, while TPP and PPA to act mainly as NPs surface crosslinkers.
Drug loading and release studies using methylene blue (MB) and doxorubicin (DOX) drug models showed covalent PPA- and HMP-based NPs to have superior loading capacities compared to NPs based on unmodified chitosan, generated by ionotropic crosslinking only or covalently crosslinked by TPP.
Doxorubicin-loaded NPs were of superior cytotoxic properties against MCF-7 cells compared to free doxorubicin.
Specifically, DOX-loaded chitosan-phthalate polyphosphoric acid-crosslinked NPs exhibited 10-folds cytotoxicity enhancement compared to free DOX.
The use of PPA and HMP to produce covalently-stabilized chitosan NPs is completely novel.
(moderately strong mineral acid with powerful dehydrating properties; used for intramolecular and intermolecular acylations, heterocyclic synthesis, and acid-catalyzed rearrangements)
Alternate Name: PPA.
Physical Data: hygroscopic, highly viscous, clear, colorless, or light amber; specific gravity 2.060 at 83% phosphorus pentoxide content.
Solubility: dissolution in any protic solvent will result in solvolysis of the reagent; dissolution in polar aprotic solvents could result in dehydration or destruction of the solvent; polyphosphoric acid is neither soluble in nor reacts with nonpolar organics such as toluene or hexane.
Form Supplied in: inexpensive and commercially available from most major suppliers.
Preparative Method: by mixing x mL of Phosphoric Acid (85%, d 1.7 g mL−1) with 2.2 x g of Phosphorus(V) Oxide (P2O5) followed by heating to 200 °C for 30 min.
Handling, Storage, and Precautions: normally used as the solvent so that a 10–50 fold excess is routinely employed.
Due to high viscosity, PPA is difficult to pour and stir at rt, but is much easier to work with at temperatures above 60 °C.
Addition of cosolvents, such as xylene, has facilitated the difficult workup usually associated with PPA.2 Eaton's reagent (see Phosphorus(V) Oxide–Methanesulfonic Acid) has been found to perform similar chemistry at lower temperatures without the viscosity problems.
When diluting PPA or working up a reaction, ice is normally used to moderate the exothermic reaction that occurs with water.
PPA has the ability to burn mucous membranes immediately and unprotected skin with time.
Other than the corrosive nature of this reagent it has low inherent toxicity.
Use in a fume hood.
Viscous water-white odorless liquid.
The commerical acid consists of a mixture of orthophosphoric acid, pyrophosphoric (diphosphoric) acid, triphosphoric and higher polymeric phosphoric acids. Sinks and mixes with water.
Air & Water Reactions
Hygroscopic. Soluble in water. Reacts with water to generate heat and phosphoric acid (orthophosphoric acid).
The reaction is not violent.
Fire Hazard
Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas.
Containers may explode when heated. For electric vehicles or equipment, ERG Guide 147 (lithium ion batteries) or ERG Guide 138 (sodium batteries) should also be consulted. (ERG, 2016)
Health Hazard
Liquid burns skin and eyes unless washed off quickly.
If ingested will burn mouth and stomach unless diluted at once. (USCG, 1999)
Reactivity Profile
POLYPHOSPHORIC ACID reacts exothermically with chemical bases (examples: amines, amides, inorganic hydroxides).
Polyphosphoric acide reactions can generate large amounts of heat in small spaces.
Reacts with or corrodes active metals, including such structural metals as aluminum and iron, to release hydrogen, a flammable gas.
Can initiate the polymerization of certain classes of organic compounds.
May catalyze chemical reactions.
Reacts with cyanide compounds to release toxic hydrogen cyanide gas.
May generate flammable and/or toxic gases in contact with dithiocarbamates, isocyanates, mercaptans, nitrides, nitriles, sulfides, and strong reducing agents. Additional gas-generating reactions may occur with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), and carbonates (CO2).
Belongs to the Following Reactive Group(s)
Acids, Weak
Potentially Incompatible Absorbents
No information available.
Response Recommendations
What is this information?
Isolation and Evacuation
Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:
As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.
SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above.
FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)
Firefighting
Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:
SMALL FIRE: Dry chemical, CO2 or water spray.
LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. Move containers from fire area if you can do it without risk.
Dike fire-control water for later disposal; do not scatter the material.
FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles.
Do not get water inside containers.
Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.
ALWAYS stay away from tanks engulfed in fire. (ERG, 2016)
Non-Fire Response
Neutralizing Agents for Acids and Caustics: Flush with water, neutralize acid with lime or soda ash. (USCG, 1999)
Protective Clothing
Goggles or face shield; rubber gloves or protective clothing. (USCG, 1999)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
INGESTION: give victim water, milk, or vegetable oil; do NOT induce vomiting.
SKIN OR EYES: flush with water for at least 15 min.; call doctor for eye exposure. (USCG, 1999)
Bitumen is used in over two hundred applications, most of which relate to civil engineering, and to paving and roofing in particular (1).
In an attempt to change its characteristics and improve its performance, bitumen is often modified with an elastomer (2, 3), a plastomer (4, 5, 6, 7), a thermoset (8, 9), sulphur (10, 11), or a mineral acid (12).
There is now much interest in the use of polyphosphoric acid (PPA) to modify bitumen.
By itself or in combination with a polymer, PPA provides a means of bitumen modification usually produced more expensively with a polymer alone.
Polyphosphoric acid is common for material formulators and developers to use bitumens of different sources is dictated by market forces.
As bitumen changes, it is often difficult to predict the effect of a modifier on bitumen and determine in advance the level of modifier required to achieve a given characteristic.
Polyphosphoric acid many cases, the modifier is dispersed in bitumen at high temperatures.
Polyphosphoric acid some cases, the modifier reacts with bitumen.
Polyphosphoric acid is the case of PPA, but the nature of the reaction is ill understood.
Polyphosphoric acid an effort to shed light on this reaction, and before PPA-modified bitumens are studied further, it is beneficial to better know the raw materials.
Consequently, we briefly review here the chemistry and the composition of bitumen and PPA.
Bitumen
Bitumen is a residue of the distillation of crude oil.
Most often this is a two-step process where atmospheric and vacuum distillations are combined, in which case straight-run bitumen is produced. When the distillation residue is oxidized in an effort to change its consistency, blown bitumen is obtained (13).
Polyphosphoric acid characteristics and composition of bitumen depend in large part on the source of the mother crude oil, for instance, Canada, Mexico, Saudi Arabia, Venezuela (14).
Polyphosphoric acid chemical complexity of bitumen precludes any precise molecular identification.
Consequently, it is often conveniently characterized by its chromatographic fractions, the maltenes and the asphaltenes (As), which are, respectively, soluble and insoluble in nheptane.
Polyphosphoric acid maltenes can be fractionated further into saturates (S), aromatics (A) and resins (R) (15, 16).
Polyphosphoric acid SARAs terminology can be confusing, however, because the aromatics fraction (A) most often contains little conjugated ring structures (14).
provides the composition of the fractions in more classical terms. The molecular weight of the SARAs increase as S<A<R<As between 300 and 1000 Daltons (17, 18). Aromatic nuclei commonly have three to five condensed aromatic rings (19).
Polyphosphoric acid bitumen molecules can thus be fairly large, with alkanes and pending alkyl chains on aromatic nuclei providing for entanglements and viscoelastic properties.
In contrast to viscoelastic polymers, however, bitumen molecules do not have identical repeat units.
Bitumen can be regarded as an oligomer with about 10 repeat units, with each repeat unit different from the next, and where the molecular weight of the repeat unit varies from about 35 Da to 90 Da (20).
Polyphosphoric acid SARAs fractions also increase in aromaticity and heteroatomic content in the order S<A<R<As (14).
In bitumen, sulfur, oxygen and nitrogen can respectively attain about 8.5%, 1.2% and 1.5% by mass (21).
Linear Formula: Hn+2PnO3n+1
CAS Number: 8017-16-1
EC Number: 232-417-0
MDL number:MFCD00084480
eCl@ss:38070203
NACRES:NA.21
We report herein an application of an α-amidoalkylation reaction, as an alternative efficient synthesis of 4-aryl- and 4-methyl-1,2,3,4-tetrahydroisoquinoline derivatives.
Polyphosphoric acid amides required for this purpose would result from reaction of aminoacetaldehyde dimethylacetal with different substituted benzenes in polyphosphoric acid, followed by acylation of the obtained amines with different acid chlorides or sulfochlorides.
We compared the cyclisation step using conventional (milieu of acetic-trifluoracetic acid = 4:1) and solid supported reagents (SiO₂/PPA), as recovered, regenerated and reused without loss of its activity catalyst.
We found that in comparison to conventional methods, the yields of the reaction are greater and the reaction time is shorter
Polyphosphoric acid temperature—viscosity curves were obtained for polyphosphoric acid with a phosphoric anhydride content of 72 to 90.75%.
Polyphosphoric acid was found that the composition of PPA remains constant for an industrially sufficient time.
The molecular-weight distribution of PPA with a different phosphoric anhydride content was determined with the published data and a scheme of the mechanism of hydrolytic degradation of PPA was proposed.
Product overview
Polyphosphoric acid is a viscous liquid produced from phosphoric acid.
Highly sought-after for its purity, our product is used in polymers, the pharmaceutical industry and in petrochemicals.
As many uses as its varied applications, with specifications on demand.
We don't know when or if this item will be back in stock.
Laboratory Chemicals
Chemicals for Lab use
Polyphosphoric Acid
Package Weight : 1.021 kilograms
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Phosphoric acid, one of the acids used in some cola drinks, is produced by the reaction of phosphorus(V) oxide, an acidic oxide, with water.
Phosphorus(V) oxide is prepared by the combustion of phosphorus.
(a) Write the empirical formula of phosphorus(V) oxide.
(b) What is the molecular formula of phosphorus(V) oxide if the molar mass is about 280 .
(c) Write balanced equations for the production of phosphorus(V) oxide and phosphoric acid.
(d) Determine the mass of phosphorus required to make of phosphoric acid, assuming a yield of 98.85
Polyphosphoric acid (PPA) is a proven modifier that improves the properties of asphalt binder.
Polyphosphoric acid has been used successfully for over 40 years and is now broadly used, either as a stand-alone modifier or in combination with various polymers.
The benefits of PPA are demonstrated in conventional and Superpave™ testing procedures, as well as in the new Multiple Stress Creep Recovery (MSCR) tests.
ICL Phosphate Specialties offers PPA in a variety of concentrations.
Most widely used are 105 and 115%. Both perform similarly, with 105% providing a lower viscosity option, and 115% a more concentrated and more viscous versions.
Which is chosen depends on the customer’s preferences and plant design.
General Information:
Leading the industry for over 65 years
Honeywell now delivers Fluka™ premium grade inorganic reagents worldwide – with consistency, purity and accuracy assured
Autoignition Temperature Not auto-flammable
Color Colorless
Corrosivity Corrosive to metals
Density 2.06 g/cm3 (20 °C)
Flashpoint Not applicable
Form Liquid
Grade Chemical Synthesis
Incompatible Materials Amines, Metals, Nitrates, Strong bases, Water
Lower Explosion Limit Not applicable
Partition Coefficient No data available
Solubility in Water Completely miscible
Upper Explosion Limit Not applicable
Vapor Pressure No data available
Viscosity No data available
pH-Value Acidic
Storage Temperature Ambient
Safety Information
Property Value
Hazard Class 8
Package Group II
UN ID UN3264
Polyphosphoric acid composition of the strong phosphoric acids,* i.e. acids containing more than 72.4y0 by weight of phosphorus pentoxide, the P?05 content of pure orthophosphoric acid, is a subject of considerable interest which has been repeatedly investigated by wet analytical methods.
Difficulties in these methods, however, have set a decided limitation on the qualitative and quantitative conclusions possible.
A study of this subject by filter-paper chron~atography was ~~ndertaken, therefore, in order to obtain further and more specific information about compositions having a mole ratio of water to phosphorus pentoxide between 3.6 and 1.2.
Polyphosphoric acid has been shown by means of paper chromatograph!. that b~, mising orthophosphoric acid with phosphorus pentoxide at different ratios, and heating the mixture at 350°C., we obtain a mixture containing o~ll, linear condensed polyphosphoric acids.
No cyclic ones were found. Branched acids, if present, would not be detected, since any ion-n~olecules with branching are expected to hydrolyze immediately upon dissolutio~l (40).
A certain characteristic quilibrium mixture exists for ever?; given ratio of water to phosphorus pentoxide.
The phosphoric acids are very viscous, so that equilibria are attained very slowly; the end result of cooling is an oil in the range 72 to 82y0 PzOj, a gum in the range 82 to 86yo PPz05, and a brittle glass at higher P205 concentrations.
These acids are merely members of a continuous series of amorphous condensed phosphoric acid mixtures which extends from orthophosphoric acid to pure phosphorus pentoxide (38).
Polyphosphoric acid mixtures are hygroscopic and hydrolyze upon standing unless stored in tightly closed pyrex containers.
Polyphosphoric acid existence of strong phosphoric acids has been known for many years.
Durgin, Lum, and Malowan (14) give a list of several such acids reported previously in the literature.
Some of these have since then been positively identified, e.g. the tetrapolyphosphoric acid, H6P4013, while for others there is enough evidence to date to make their existence highly improbable, e.g. the metaphosphoric acid monomer, HPOZ.
Finally, some of the acids listed by the above-mentioned authors, which at the time represented merely theoretical combinations of phosphorus pentoxide and water, have during the present study been positively identified as far as this is possible by paper chromatography, and their relative concentrations in several mixtures accurately established, e.g. "hexerohexaphosphoric" acid, HsP6Ol9, better lrnown today as hexapolyphosphoric acid.
Polyphosphoric acid same authors checked the analytical methods of Gerber and Miles (19) against those of Britske and Dragunov (6) and found an increasing divergence when acids of high phosphorus perltoxide content were being analyzed.
This they considered as evidence that polyphosphoric acids may be present in the strong phosphoric acids.
Bell (3) went a step further by recognizing that tripolyphosphoric acid is present and interferes in some procedures for pyrophosphate determination.
By using an analytical method previously developed by the same author (5), he was able to show the presence of ortho-, pyro-, and tripolyphosphoric acids in several of the strong phosphoric acid mixtures, and of "the polymer of metaphosphoric acid commonly known as hexametaphosphoric acid".
A11 "unidentified" acid, indicated by difference, was also present between 78 and 88% phosphorus pentoxide.
Although the exact compositioil of the strong phosphoric acid mixtures had not been established, several of their physical and chemical properties as a function of their phosphorus pentoxide content were reported in the literature. These include, among others, measurements of densities (14, 23), viscosities (14), vapor pressures (7), boiling points and compositioi~ of the vapor over the boiling mixture (38), and heats of vaporization (38).
By boiling orthophosphoric acid an azeotropic mixture was obtained (b.p. 86g°C., 753 mm. Hg) containing 92.1% phosphorus pentoxide (34). Vapor-density measurements indicated that the vaporized acids dissociate into water and phosphorus pentoxide at temperatures near 1000°C.
Polyphosphoric acids (PPA) are reactive oligomers having a short-chain polymer.
Polyphosphoric acid inorganic chemicals are odorless, colorless, highly viscous liquids and possess strong hygroscopic properties.
Phosphorus pentoxide (P2O5) and phosphoric acid (H3PO4) are two basic compounds used in the production of polyphosphoric acid (PPA).
Polyphosphoric acid preparation procedure includes heating and dehydration of phosphoric acid followed by a polycondensation process.
Polyphosphoric acid (PPA) is available in various grades in the market.
Polyphosphoric acids (PPA) are utilized in a wide variety of reagent applications in the chemical industry.
These powerful dehydrating agents for organic synthesis, and intermediate for the production of phosphate esters with high mono-ester content.
As a catalyst, polyphosphoric acid (PPA) is employed in petroleum and petrochemical for several processes such as dehydration, polymerization, alkylation, isomerization processes, and condensation.
These compounds are also used in the metal treatment and as an asphalt and bitumen additive.
Demand for polyphosphoric acid (PPA) as a catalyst in numerous polymerization reactions is rising.
Polyphosphoric acid, significant expansion of the polymer and plastic industry is estimated to increase the demand for polyphosphoric acids (PPA) and subsequently, fuel the market.
In the oil & gas sector, the dehydrating process is a crucial part of upstream operations.
Surge in production of oil & gas, globally, is anticipated to propel the demand for dehydrating agent and subsequently, drive the demand for polyphosphoric acid (PPA).
Polyphosphoric acid (PPA) also plays an indispensable role in chemical intermediates. Therefore, a surge in the demand for petrochemical and chemical products is estimated to augment the polyphosphoric acid (PPA) market during the forecast period.
However, polyphosphoric acid (PPA) exhibits numerous harmful effects on the environment which is projected to hinder the market.
Moreover, the stringent regulatory framework associated with the consumption of bio-based chemicals is also likely to hamper the demand for polyphosphoric acid (PPA) in numerous industrial applications.
The outbreak of COVID 19 has adversely impacted the global economy, as governments undertook lockdown measures to curb the spread of the virus.
Various manufacturing activities were halted across different end-use industries. This led to weakened demand for polyphosphoric acid (PPA).
The prevailing macro environment shall register signs of recovery based on the prevalence of COVID 19 and subsequent resumption of manufacturing plants.
Dialkylamino-substituted indolin-2(3H)-ones were prepared by cyclisation of the required mandelanilides with hot polyphosphoric acid.
A new reagent (PPEt) obtained from polyphosphoric acid and ethanol produced imidazoquinolines from aminobenzimidazoles and β-keto-esters and a 1,8-naphthyridine from 2-aminopyridine and ethyl α-methylacetoacetate, reactions which could not be brought about by PPA.
The scope of the new reagent is discussed.
Polyphosphoric acid was also shown that PPA offers no advantage over sulphuric acid in various Skraup reactions.
Polyphosphoric acid review discusses the advances in the use of silica-supported polyphosphoric acid (PPA-SiO2) as a green and reusable heterogeneous catalyst in the preparation of various organic compounds and pharmaceutical intermediates.
PPA-SiO2 could be recovered and reused several times without significant loss of their efficiency.
In this review, we attempt to give an overview of the applications of PPA-SiO2 as a catalyst in condensation, cyclization, and addition reactions for the preparation of various organic compounds.
This Thermo Scientific brand product was originally part of the Acros Organics product portfolio.
Some documentation and label information may refer to the legacy brand.
Polyphosphoric acid original Acros Organics product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific.
Polyphosphoric acid chemical and petrochemical sector is responsible for more than 30% of total industrial energy consumption worldwide (including feedstocks), making it by far the largest industrial energy user.
The phosphate industry is no exception, with demand growing, especially for polyphosphoric acid, from a range of purposes, including for pharmaceuticals, cosmetics, petrochemicals, road construction (asphalt), textiles, water treatment and fertilisers.
In 2009, worldwide polyphosphoric acid production reached more than 50 kilotonnes (kT), with an annual growth rate of 4.2%.
More than 60% (31.91 kT) of this production is currently achieved via a thermal process (by applying heat), which has a major environmental impact and is very energy consuming.
OBJECTIVES
Polyphosphoric acid LIFE Polyphos Acid project planned to establish a pilot process for the production of highly purified polyphosphoric acid (85% P2O5) using an innovative wet process that is less polluting and more energy efficient.
However, it is more complex than the thermal process and as a result it is not as widely used.
The wet process consists of transforming phosphate rock into a first intermediate product, the raw acid (60% P2O5), which is then made into purified acid (63% P2O5), which can be finally converted into the purified polyphosphoric acid (85% P2O5).
Polyphosphoric acid project aimed to focus on this last step in the production process, planning to build a pilot-scale facility at the beneficiarys premises.
Polyphosphoric acid site would comprise a flame chamber (the first sub-system and also the main innovative element), a second critical sub-system (the mass and energy recuperator), and finally the gas treatment equipment.
Polyphosphoric acid new patented process was expected to substantially reduce energy consumption and greenhouse gas emissions, while reducing waste.
RESULTS
Polyphosphoric acid LIFE Polyphos Acid project partly reached its objectives.
Polyphosphoric acid installation of the full pilot, which connected the three sub-units, was finalised only at the end of the project, meaning that it did not start producing polyphosphoric acid within the established timeframe.
However, the design and construction of the vital sub-units the flame chamber, recuperator and gas treatment unit represent a key outcome of the project, with a prototype silicon carbide (SiC) flame chamber shown to be particularly robust.
Furthermore, the project demonstrated the feasibility of producing purified polyphosphoric acid (exceeding the target of 85% P2O5) with the silicon carbide flame chamber connected to the facilities of the pilot R&D.
Life Cycle Analysis LCA, based on tests with the pilot R&D, showed that the innovative wet process will lower the systems overall carbon footprint and reduce energy consumption by more than 80% compared to the most polluting thermal processes currently used.
Delays in the project related to the use of silicon carbide solid material, which has been shown to improve the heat resistance and corrosion of the flame chamberwithout increasing the cost of the system.
However, plain silicon carbide is a novel solution and only a limited number of suppliers are able to manufacture the required components and those that do expressed to reluctance to cooperate.
Therefore, the beneficiary itself took over this aspect of supply, which delayed the initial schedule.
Polyphosphoric acid prototype recuperator prioritised the recovery of residual acid in hot gases from the flame chamber.
Heat recovery should be demonstrable when the pilot is recreated on an industrial scale.
Polyphosphoric acid beneficiary is continuing to develop the pilot using its own funds.
Polyphosphoric acidis looking to scale up the pilot apparatus to industrial level at its production sites.
A pre-industrial business plan was developed and a major stakeholder in the phosphates industry has expressed a strong interested in the project process.
Polyphosphoric acid project addresses the European Commissions Roadmap for moving to a competitive low carbon economy in 2050, as well as the Policy framework for climate and energy in the period from 2020 to 2030.
Polyphosphoric acid also shows how to implement aspects of the EU Directives on Energy Efficiency and Waste.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).
Polyphosphoric acid (PPA) has been increasingly used as a means of producing modified binders for the past 10 to 15 years in North America.
Reports of isolated or regional use of phosphoric acid and PPA prior to the advent of Superpave performance grade (PG) binders have been published, but the increased demand for high-performance binders resulting from the adoption of PG binders stimulated more widespread research into the means by which PPA could effectively and economically enable binder suppliers to meet these demands.
Consequently asphalt suppliers in all regions of the United States and Canada turned to PPA to meet the new specifications.
Polyphosphoric acid was found that PPA, when used at levels as low as 0.5% by weight of binder, could increase the high-temperature PG of some binders by one full grade.
Most binders required approximately 0.8% to 1.2% PPA by weight of binder and some required considerably more; sometimes more than 2%.
Still other asphalt suppliers found that the addition of low levels, typically less than 0.5% by weight, of PPA to polymer-modified binders enabled them to reduce polymer loading without negatively impacting mixture performance and in some reported cases enhancing mixture performance.
Almost simultaneously with the onset of PPA usage, concerns were raised by a cross section of individuals, organizations, and agencies associated with the asphalt production and supply, bituminous paving and governmental sectors.
Polyphosphoric acid concerns were manifested by fears of mixture stripping because of the hygroscopic nature of PPA and fears of accelerated aging and adverse effects on low-temperature properties of both binders and their mixtures because of the well-known use of phosphoric acids, PPA, and phosphorus pentoxide to catalyze the production of roofing asphalt during the blowing process.
Polyphosphoric acid was also the often unstated but ever-present belief that purchasers of PPA-modified binders were being cheated because they were not receiving polymer when purchasing some premium PG grades.
Some of these concerns were justified, many were not.
The information in this study endeavors to put some perspective around these concerns, to show where there might be cause for concern and where there is not.
This document does not provide an answer to all questions and it raises a few questions that still need to be answered.
We report herein an application of an α-amidoalkylation reaction, as an alternative efficient synthesis of 4-aryl- and 4-methyl-1,2,3,4-tetrahydroisoquinoline derivatives.
Polyphosphoric acid amides required for this purpose would result from reaction of aminoacetaldehyde dimethylacetal with different substituted benzenes in polyphosphoric acid, followed by acylation of the obtained amines with different acid chlorides or sulfochlorides.
We compared the cyclisation step using conventional (milieu of acetic-trifluoracetic acid = 4:1) and solid supported reagents (SiO2/PPA), as recovered, regenerated and reused without loss of its activity catalyst.
We found that in comparison to conventional methods, the yields of the reaction are greater and the reaction time is shorter.
What is PPA
Polyphosphoric acid (Hn+2PnO3n+1) is a polymer of orthophosphoric acid (H3PO4).
Polyphosphoric acid offered commercially is a mixture of orthophosphoric acid with pyrophosphoric acid, triphosphoric and higher acids and is sold on the basis of its calculated content of H3PO4 as for example 115%.
Superphosphoric acid is a similar mixture sold at 105% H3PO4. Other grades of phosphoric acid may contain water, but are not typically used in asphalt modification.
Polyphosphoric acid eliminates issues of foaming and corrosion at the refinery or terminal.
PPA’s major applications are surfactant production, water treatment, pharmaceutical synthesis, pigment production, flame proofing, metals finishing and asphalt modification.
This circular will specifically discuss the use of PPA as an asphalt modification.
There have been several patents on the use of Polyphosphoric acid with asphalt.
One of the first patents for binder modification was in 1973. This patent involved adding PPA to the asphalt binder to increase viscosity without increasing the penetration.
Subsequent patents typically involve the use of PPA with polymer modification.
Polyphosphoric acid past experience has shown PPA increases the high temperature stiffness of an asphalt binder with only minor effect on the intermediate and low temperature properties.
How is PPA Used The Superpave Performance Grade (PG) binder specification is used predominantly in the US.
Polyphosphoric acid the PG system the high and low temperature performance range is specified i.e., PG 64-22.
Polyphosphoric acid 64 represents the expected high temperature range of the binder and the -22 is the expected low temperature range.
The difference between the high and low temperature range of the binder is call the useful temperature interval (UTI).
A PG 64-22 would have a UTI of 86°C or 64 – (-22) = 86°C. All asphalt binders refined from crude oil have a specific UTI.
Changes in the refining process can shift the UTI up or down, but in general they cannot change the UTI.
A specific crude may be refined to make a PG 58-28 or PG 64-22 or PG 70-16, but it cannot be refined into a PG 70-22.
To change the UTI of an asphalt binder it would have to be blended with an asphalt binder which has a different UTI or modified with some type of additive.
Polyphosphoric acid use of the Superpave binder specification has encouraged agencies to specify stretch grades. These are grades that go beyond the UTI of most neat asphalts.
A PG 76-22 would require a UTI of 98C, well beyond most normally refined asphalts. To meet the requirements for these grades some type of modification is needed.
In many cases this would be a polymer. Polymers do quite well in increasing the high temperature properties of a binder.
However, polymer modification can also affect the intermediate temperature properties of some asphalt binders.
In cases where adding polymer in percentages greater than about 3% is needed to change a PG 64-22 to a PG 76- there will be a tendency to raise the intermediate stiffness of the binder so the grade may come out to be a PG 76-16.
Polyphosphoric acid use of PPA in combination with the polymer will minimize the increase in stiffness of the intermediate stiffness and allow for the production of the PG 76-22.
Polyphosphoric acid amount of PPA needed will vary based on the crude source and polymer being used.
One question is how much PPA is required to change a binder one high temperature PG grade and does PPA have the same effect on all asphalt binders.
To evaluate this 105% PPA was added to 2 very different binders from different crude sources.
PPA at 0.5% by wt. of binder was added to a PG 70-22 refined from Venezuelan crude and a PG 64-22 refined from Saudi crude.
