N-Methyl-2-Pyrrolidone CAS 872-50-4

What is N-Methyl-2-Pyrrolidone?

N-methyl-2-pyrrolidone is a polar aprotic solvent, C₅H₉NO, a clear, high-boiling liquid with a mild amine odour, completely miscible with water and with most organic solvents.

Its dissolving power is exceptional. NMP dissolves polymers, resins and aromatics that ordinary solvents cannot touch, while boiling high enough at 202 °C to be used in hot processes.

Lithium-ion battery electrode manufacture has become the largest and fastest-growing outlet, where NMP dissolves PVDF binder for cathode slurry coating and is then recovered.

NMP is classified as toxic for reproduction in the EU and is restricted under REACH with a derived no-effect level, which has driven substitution in consumer and paint-stripping applications while industrial use continues under controls.

Why NMP specifically

• Exceptional solvency. Dissolves PVDF, polyimides, aromatics and many polymers that resist ordinary solvents.
• High boiling point. At 202 °C it stays liquid in hot extraction and coating processes where volatile solvents would flash off.
• Fully water miscible. Simplifies formulation, cleaning and recovery.
• Chemically and thermally stable. Can be recovered and recycled many times, which matters at battery plant scale.

How N-Methyl-2-Pyrrolidone is Manufactured

NMP is made by reacting gamma-butyrolactone with methylamine, with purity grades requiring extensive finishing.

• GBL feed. Gamma-butyrolactone, from the maleic anhydride or acetylene route, is the main raw material.
• Methylamine reaction. GBL reacts with aqueous methylamine at elevated temperature and pressure to form NMP and water.
• Dehydration. Water is removed and unreacted methylamine recovered and recycled.
• Distillation. Vacuum distillation separates NMP from heavy ends and residual GBL.
• Colour and metals control. Battery and electronic grades receive additional treatment to remove colour bodies and trace metals.
• Blanketing and packing. High-purity grades are nitrogen blanketed, since NMP picks up water and oxidises slowly in air.

Typical Commercial Specification

Figures below are representative of technical-grade NMP. Battery and electronic grades carry far tighter metals, water and colour limits — tell us the use and we will send the matching sheet.

Physical & Chemical Properties

Behaviour in the process

NMP's polarity and high boiling point give it both its usefulness and its handling requirements:

• Strongly hygroscopic. Absorbs water rapidly from air, which matters critically in battery slurry preparation.
• Dissolves many plastics. Attacks PVC, polycarbonate and many elastomers; check all wetted materials before use.
• Absorbed through skin. Readily penetrates skin, which is central to its reproductive toxicity classification.
• Recoverable. Thermally stable enough for repeated distillation and recycling, which battery plants depend on.

NMP Grades and Alternative Solvents

NMP is bought by grade, and the gap between technical and battery grade is wider than for almost any other solvent we handle.

Stated plainly: the substitutes for NMP in battery manufacture are being developed under regulatory pressure rather than chosen for performance, and none yet matches it for PVDF dissolution. In paint stripping and consumer products the substitution has already largely happened.

Industries We Supply N-Methyl-2-Pyrrolidone To

NMP serves batteries, electronics, petrochemicals, pharmaceuticals and coatings.

Where N-Methyl-2-Pyrrolidone is Used

Lithium battery electrode manufacture is now the largest NMP outlet, with electronics and petrochemical extraction behind it.

In lithium battery manufacture

NMP dissolves PVDF binder so that active cathode material can be coated onto aluminium foil as a uniform slurry. The solvent is then evaporated and recovered — recovery rates above 99% are now standard because of both cost and emissions regulation. Water and trace metals in the NMP carry directly into the cell, which is why battery grade is specified at sub-ppm metals and below 200 ppm water.

Regulatory position

NMP is classified as toxic for reproduction Category 1B in the EU and carries a REACH restriction with a derived no-effect level for workers. This has removed it from consumer paint strippers and pushed industrial users toward closed handling, local exhaust and documented exposure assessment. Industrial use continues, but with a compliance burden that did not exist a decade ago.

Quality Control & Testing

Every lot is released against a batch-specific Certificate of Analysis, with water and trace metals reported in full for battery and electronic grades.

• NMP purity and water content — by gas chromatography and Karl Fischer titration.
• Trace metals — iron, sodium, calcium and others at sub-ppm for battery grade.
• Colour — by APHA, a sensitive indicator of oxidation and contamination.
• Acidity — measured because it rises with hydrolysis and oxidation.
• GBL and methylamine residues — the characteristic process impurities.
• Non-volatile residue and particles — critical for electronic and battery applications.

Common Process Problems & Likely Causes

When NMP causes trouble, it is usually water, metals or colour. This table is the shortcut our technical desk works through before anyone opens a complaint file.

Packaging, Storage & Shipping

• Standard packing. 200 L drums, 1000 L IBCs, ISO tank containers and bulk, nitrogen blanketed for high-purity grades.
• Moisture protection. NMP is strongly hygroscopic; keep containers sealed and blanket battery-grade storage with dry nitrogen.
• Material compatibility. Stainless steel is standard. NMP attacks PVC, polycarbonate and many elastomers — check every wetted part.
• Storage. Cool, dry, bunded storage; NMP is a combustible rather than flammable liquid with a 91 °C flash point.
• Skin protection. Use gloves rated for NMP and change them regularly; NMP permeates many glove materials faster than expected.
• Dedicated equipment. For battery and electronic grades, dedicated lines and containers with cleaning records.
• Shelf life. Typically 24 months in sealed, blanketed storage; colour and water are the practical checks.
• Transport classification. Not classified as dangerous goods for transport.

Hazards & Safe Handling

NMP is not flammable in normal handling and has low acute toxicity, but it is classified as toxic for reproduction and is readily absorbed through skin. Dermal exposure control is the central safety issue.

• Reproductive toxicity. Classified Category 1B, may damage the unborn child. Exposure must be controlled, with particular attention to workers of reproductive age.
• Skin absorption. Readily absorbed through intact skin. Gloves must be selected on breakthrough time, not just material type, and changed regularly.
• REACH restriction. Subject to a REACH restriction with a derived no-effect level requiring documented exposure assessment for industrial use in the EU.
• Eye and respiratory irritation. Irritating to eyes and respiratory tract; the mild odour is not a reliable exposure warning.
• Occupational exposure. Limits are low; confirm the applicable value and the DNEL in your jurisdiction.
• Combustible liquid. Flash point about 91 °C — not highly flammable, but it will burn in a fire.
• Hot handling. Used hot in many processes, adding a thermal burn risk.
• Environment. Contain spills; NMP is miscible with water and spreads readily.

Regulatory & Compliance Notes

NMP is one of the more heavily regulated industrial solvents, with a REACH restriction and reproductive toxicity classification. The notes below are orientation rather than legal advice.

• GHS classification. Reproductive toxicity Category 1B, skin and eye irritation, and STOT SE Category 3 for respiratory irritation.
• REACH restriction. Restricted in the EU with a derived no-effect level; industrial users must demonstrate exposure control below the DNEL.
• Consumer prohibition. Removed from consumer paint strippers and similar products in the EU and several other jurisdictions.
• Transport. Not classified as dangerous goods. Standard packaged and bulk cargo documentation applies.
• Occupational exposure regulation. Exposure limits with skin notation apply in most jurisdictions.
• Battery industry specifications. Battery-grade NMP is specified contractually on metals, water and particles rather than by public standard.

We Supply N-Methyl-2-Pyrrolidone Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship N-Methyl-2-Pyrrolidone from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, transport paperwork and freight so the material arrives ready to use.

• Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
• Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged where routing and cargo rules allow.
• Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and the transport declaration issued as a complete set.
• Flexible volumes. From a pallet of drums up to repeat bulk shipments on a supply contract.
• Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.

Buying N-Methyl-2-Pyrrolidone from Chelora

We are an independent sourcing and supply partner. For NMP that means settling three things at enquiry: the grade and the water and metals limits your process requires, whether REACH exposure documentation is needed for your jurisdiction, and the blanketed handling route into your plant.

• Documentation on every lot. Batch-specific COA (purity, water, metals, colour), plus SDS and the full transport paperwork.
• Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
• Quantities. From a pallet of drums through to full bulk shipments on contract supply.
• Grade matching. Technical, electronic or battery grade NMP to the purity, water, metals and colour limits your process requires.
• Inspection. Independent third-party inspection available at loading when the contract requires it.
• Related products. Dimethylformamide, Triethylene Glycol, Acetone and other feedstocks alongside N-Methyl-2-Pyrrolidone from one supplier.

How ordering works

• Send the enquiry. Product, grade or purity, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
• We quote. Price, lead time, packing format and a sample COA, normally within one working day.
• Qualify the supply. For first orders or critical applications, we share the analysis and handling documentation so your technical and safety teams can sign off before you commit.
• Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
• Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
• Ship and document. Filled, labelled and loaded with the full export document set, and tracked through to arrival.

Related Products

Buyers of NMP often source other polar solvents alongside it — DMF and specialty solvents are commonly bought on the same programme.