Sodium 4-Hydroxybenzoate (CAS 114-63-6) Applications
Sodium 4-Hydroxybenzoate (CAS 114-63-6), also known as Sodium PHBA or Monosodium p-hydroxybenzoate, is the monosodium salt of p-hydroxybenzoic acid with the molecular formula C₇H₅NaO₃ and molecular weight 160.10 g/mol. The sodium salt form offers markedly higher cold-water solubility than the parent acid, making it convenient to handle in aqueous chemistry.
• Hydroxyaromatic Building Block
The 4-hydroxybenzoate scaffold is a widely used hydroxyaromatic carboxylate motif in synthetic chemistry. Its sodium salt form provides aqueous handling convenience for downstream esterification, etherification, and salt-metathesis chemistry. Use of this scaffold as a synthetic intermediate is a class of use that has been established in the fine chemicals industry for several decades.
Typical Use Areas: hydroxybenzoate ester synthesis, aromatic carboxylate intermediates, hydroxyaromatic coupling chemistry
• Polymer Feedstock Chain
4-Hydroxybenzoic acid (PHBA), recoverable from its sodium salt by acidification, is a long-established monomer in aromatic polymer chemistry. The downstream PHBA-based polymer family has supported industrial applications for several decades and remains an active area of formulation development by polymer producers.
Typical Use Areas: PHBA precursor supply, aromatic polyester feedstock chain, hydroxyaromatic monomer recovery
• Personal Care & Formulation Chemistry
The hydroxybenzoate family has a long history of use in personal care and household formulation chemistry, with the sodium salt form offering improved aqueous compatibility relative to the free acid. End-use suitability, regional regulatory status (e.g., EU Regulation 1223/2009 Annex V, US FDA 21 CFR 184), and concentration limits remain the responsibility of the formulator.
Typical Use Areas: aqueous personal care formulations, household formulation chemistry, hydroxybenzoate salt handling in water-based systems
Handling Note: The sodium salt form dissolves readily in cold water without the heating or co-solvent often required for the parent acid, which can simplify aqueous-phase handling in production environments.
