pH-Responsive Basic Homopolymer
Poly(4-vinylpyridine)
Also known as P4VP, poly(p-vinylpyridine) | CAS 25232-41-1
A vinyl homopolymer with a pendant pyridine ring on every repeat unit. The pyridine nitrogen’s lone pair makes P4VP a weak base — protonating and becoming water-soluble/cationic at low pH — and a strong coordinating ligand for transition-metal ions, which is why it’s a standard building block in block copolymer self-assembly and metal-nanoparticle synthesis.
- Multiple Mw grades, linear and crosslinked (resin) forms
CAS 25232-41-1
(C₇H₇N)ₙ
Poly(4-vinylpyridine)
Appearance: White to off-white powder
Character:Weak base, pH-responsive
Decomposition: ~260 °C
Density: ~1.15 g/cm³
ISO 9001:2015
Manufactured under certified quality management
Custom MPC Ratio
Mol% MPC content configurable to your spec
Batch-Level COA
Spectral data and free-dye content per lot
Sample to Bulk
1 g R&D vials up to multi-gram supply
MPC Monomer CAS
67881-98-5
HEMA Monomer CAS
868-77-9
Structure
Random copolymer
Key Property
Protein-resistant
Package
1g / 10g / 100g
Why the pyridine nitrogen is the whole story
Nearly every application of P4VP traces back to one feature: a nitrogen lone pair sitting on every repeat unit, ready to either grab a proton or coordinate a metal ion.
pH-triggered protonation
Below its apparent pKa (~4–5), the pyridine N picks up a proton and the chain becomes cationic and water-soluble; above it, the chain is neutral and hydrophobic.
Metal-ion coordination
The same lone pair binds transition-metal ions (Au³⁺, Ag⁺, Pt²⁺), making P4VP domains act as a polydentate ligand for nanoparticle nucleation and stabilization.
Microphase separation
In block copolymers like PS-b-P4VP, its polarity contrast with the other block drives self-assembly into ordered nanostructures for templating.
Quaternizable
The pyridine N can be alkylated to form a permanently cationic, water-soluble polyelectrolyte for ion-exchange or LbL applications.
Values below apply to our standard linear grade. Batch-specific COAs with GPC data are available on request.
| CAS Number | 25232-41-1 |
|---|---|
| Synonyms | P4VP · Poly(4-pyridylethylene) · Poly(p-vinylpyridine) · 4-Vinylpyridine homopolymer |
| Molecular Formula | (C₇H₇N)ₙ |
| Repeat Unit Weight | 105.14 g/mol |
| SMILES (monomer) | C=CC1=CC=NC=C1 |
| Appearance | White to off-white powder |
| Density | ~1.15 g/cm³ |
| Decomposition Temperature | ~260 °C |
| Approx. pKa (pyridinium) | ~4 – 5 |
| Solubility | Soluble in lower alcohols, DMF, chloroform, acetic acid; pH-dependent solubility in water; insoluble in nonpolar hydrocarbons |
| Available Forms | Linear (soluble) or crosslinked (bead/resin, ion-exchange grade) |
| Storage Conditions | Room temperature, sealed, protected from moisture |
Need a narrow-dispersity grade for block copolymer synthesis, or the crosslinked resin form? Talk to technical sales →
Choose the grade that fits your process
Chain length affects solution viscosity, self-assembly domain spacing, and film-forming behavior.
Mw 20,000–60,000
Low Mw
Lower viscosity solutions — suits coatings, sensor modification, and small-scale nanoparticle templating.
Mw 60,000–160,000
Mid Mw
Balanced grade for most block copolymer synthesis and general research use.
Mw 160,000–200,000+
High Mw
Higher solution viscosity and film strength for membrane and larger-domain templating work.
Applications
Block copolymer self-assembly
A standard segment (e.g. PS-b-P4VP) for microphase-separated nanostructures used in lithography templates.
Metal nanoparticle synthesis
Coordinates Au, Ag, and Pt precursor ions within micellar cores to template nanoparticle size and shape.
pH-responsive membranes
Gates mass transport by switching between swollen/cationic and collapsed/neutral states with pH.
Ion-exchange resins
Crosslinked P4VP beads act as a weak-base anion exchanger for purification and catalysis applications.
Electrochemical sensors
Modifies glassy carbon electrodes to improve sensitivity and selectivity in voltammetric detection.
Layer-by-layer assembly
Protonated or quaternized P4VP serves as the cationic layer in electrostatic LbL film construction
Corrosion-inhibitor coatings
Pyridine N coordinates to metal surfaces, supporting corrosion-inhibiting coating research.
Supramolecular complexation
Forms hydrogen-bonded complexes with proton-donating polymers (e.g. PAA) for micelle and hollow-sphere self-assembly.
Data & safety documents
Batch-specific COAs with GPC data available for order confirmations. Contact us for a specific lot number.
Safety Data Sheet
GHS-format · EN / ZH
Certificate of Analysis
Ratio + Mw confirmation
¹H-NMR Spectrum
Structure confirmation
FAQ
Most frequent questions and answers
It’s pH-dependent. Below its apparent pKa (~4–5), the pyridine nitrogen protonates and the chain becomes cationic and water-soluble. Near neutral or higher pH, it’s largely deprotonated, neutral, and insoluble in water — though it does dissolve in lower alcohols, DMF, chloroform, and acetic acid regardless of pH.
The pyridine nitrogen sits at a different ring position — 4- versus 2- relative to the vinyl attachment. This changes steric accessibility of the nitrogen lone pair and shifts solubility parameters and metal-coordination behavior slightly. P4VP is generally more miscible in higher-polarity solvents; the two are not interchangeable in block copolymer phase-diagram work.
The pyridine nitrogen’s lone pair binds metal ions (e.g. Au³⁺, Ag⁺, Pt²⁺) directly, acting as a polydentate ligand. In block copolymer micelles, this lets the P4VP domain sequester metal precursor before reduction, controlling the size and distribution of the resulting nanoparticles.
The linear form is soluble in organic solvents and used for solution-based work — coatings, block copolymers, sensor modification. The crosslinked form is an insoluble bead/resin used mainly as a weak-base ion-exchange resin. Specify which form you need when requesting a quote.
Yes — unlike our custom copolymer grades, P4VP is a well-defined homopolymer with one CAS Registry Number (25232-41-1) across molecular weight grades. Note that crosslinked/resin variants are sometimes listed under a separate CAS by some suppliers, so confirm which form you’re ordering.
Store at room temperature, sealed, and protected from moisture. Decomposition above ~260°C releases hazardous fumes, so avoid high-heat processing without appropriate ventilation.