It is a colorless liquid, although impure samples are often brown.

It is a monomeric precursor to specialty polymers.

[1] 4-VP is sometimes used in biochemistry to alkylate protein cysteine residues.

When compared to other alkylation agents, such as iodoacetamide, acrylamide, and N-ethylmaleimide, 4-VP is less reactive, meaning the completion rate of cysteine alkylation is lower, but it also yields fewer side reactions.

[2] For some uses, such as during mass spectrometry measurements, 4-VP might be better because it is basic and can thus be protonated, adding net charge.