p-Toluenesulfonic Acid (PTSA)

What Is p-Toluenesulfonic Acid?

p-Toluenesulfonic acid, abbreviated as PTSA or p-TSA, is a strong organic sulfonic acid used as an acid catalyst, synthesis reagent and specialty chemical intermediate.

Commercial PTSA is commonly supplied as a monohydrate, an anhydrous product or a solution. Buyers must confirm the physical form because each version has a different water content, molecular weight and application profile.

AOZUN supports PTSA sourcing for organic synthesis, resins, coatings and other industrial applications. Grade, concentration, specification and packaging are confirmed according to the customer’s requirements.

Which PTSA Form Should You Buy?

PTSA monohydrate is the most common solid commercial form. Anhydrous PTSA may be selected for moisture-sensitive synthesis, while solution grades can simplify industrial dosing.

The name “PTSA” alone is not sufficient for an RFQ. Buyers should state the required form, CAS number, assay basis and water limit.

PTSA Identification and Typical Properties

Product appearance and specifications can vary by grade. The agreed specification and batch COA should govern commercial acceptance.

What Is p-Toluenesulfonic Acid Used For?

Esterification and Transesterification

PTSA is used as an acid catalyst in ester production and related condensation reactions. Its solid form can make weighing and dosing easier than some liquid mineral acids.

Acetalization and Organic Synthesis

PTSA can catalyze acetalization, dehydration, protection and deprotection reactions. It is widely used in laboratory and industrial organic synthesis.

Resins, Coatings and Polymer Processing

PTSA and formulated PTSA solutions may be used as curing or reaction catalysts in selected resin and coating systems. Compatibility, catalyst concentration and cure conditions must be validated in the customer’s formulation.

Fine Chemical Intermediates

PTSA is used in the preparation of tosylates, pharmaceutical intermediates, agrochemical intermediates, dyes and other specialty organic compounds.

Analytical and Laboratory Applications

Higher-purity grades can be used as laboratory reagents or in applications requiring tighter limits for metals, sulfate, residue or other impurities.

Which PTSA Specifications Matter Most?

The most suitable PTSA grade depends on water sensitivity, catalyst performance, product color and downstream impurity limits.

The analytical method and acceptance limit should be agreed before ordering. Purity values obtained by titration and chromatography should not automatically be treated as equivalent.

How Do Water and Free Sulfuric Acid Affect PTSA Performance?

Water content can influence reaction equilibrium, conversion and drying requirements. This is especially important in esterification, acetalization and moisture-sensitive synthesis.

Free sulfuric acid may increase corrosiveness and can change reaction selectivity or final-product color. Buyers using PTSA in coatings, resins or high-purity synthesis should define an acceptable free-sulfuric-acid limit.

For monohydrate products, confirm whether the reported assay is calculated on a dry basis or on the material as supplied.

PTSA Packaging, Storage and Safety

PTSA is hygroscopic and should be stored in tightly closed, corrosion-compatible packaging in a cool, dry and well-ventilated place. Protect it from moisture, excessive heat and incompatible materials.

Some PTSA products can develop a pale-pink color during storage. Color requirements should therefore be agreed for sensitive applications.

PTSA can cause severe skin burns and eye damage. Operators should use suitable gloves, protective clothing, eye protection and ventilation. Always follow the current SDS and local handling regulations.

Which Documents Should a PTSA Supplier Provide?

Depending on the application, buyers may request:

• Batch-specific Certificate of Analysis

• Safety Data Sheet

• Product specification or Technical Data Sheet

• Assay and water-content methods

• Free-sulfuric-acid and isomer data

• Trace-metal or residue information

• Country of origin

• Manufacturing or retest date

• Packaging and transport information

Documents should be reviewed before PTSA is approved for production or regulated applications.

Why Source p-Toluenesulfonic Acid from AOZUN?

AOZUN helps customers define the required PTSA form, assay basis, water content, impurity limits, packaging and delivery conditions before quotation.

Availability and specifications are confirmed according to the requested application and current supply conditions. COA, SDS and supporting technical documents can be requested for evaluation.

Frequently Asked Questions About PTSA

Is p-toluenesulfonic acid organic or inorganic?

PTSA is an organic aromatic sulfonic acid. Although it is strongly acidic, it is not an inorganic mineral acid.

Is PTSA a fine chemical or an intermediate?

It is primarily classified as an organic fine chemical and acid catalyst. It can also function as an intermediate in the production of tosylates and specialty chemicals.

Are CAS 6192-52-5 and 104-15-4 the same product?

They represent different forms. CAS 6192-52-5 is PTSA monohydrate, while CAS 104-15-4 identifies anhydrous p-toluenesulfonic acid.

Why is PTSA purity sometimes reported after drying?

Reporting the result after drying removes the contribution of water from the assay calculation. Buyers should check whether the specification is dry-basis or as-received.

Can PTSA monohydrate replace anhydrous PTSA?

Not automatically. The additional water may affect moisture-sensitive reactions, equilibrium and dosage calculations.

What information should be included in a PTSA inquiry?

Include the PTSA form, CAS number, required assay, water limit, free-sulfuric-acid limit, quantity, packaging, application and destination.

Request a Quote for p-Toluenesulfonic Acid

To receive an accurate quotation, please provide:

• Required PTSA form or concentration

• CAS 6192-52-5 or CAS 104-15-4

• Required assay and calculation basis

• Water and free-sulfuric-acid limits

• Intended application

• Required quantity and packaging

• Destination country

• Required documents

Contact AOZUN to discuss PTSA specifications, packaging, documentation and current availability.