4-Hydroxybenzoic Acid

Catalog	BBC99967
CAS	99-96-7
Structure
Description	PelletsLargeCrystals;Solid;Solid;White crystalline powder; faint nutty odour
Synonyms	p-Hydroxybenzoic
IUPAC Name	4-Hydroxybenzoic acid
Molecular Weight	138.12
Molecular Formula	C7H6O3
Canonical SMILES	C1=CC(=CC=C1C(=O)O)O
InChI	InChI=1S/C7H6O3/c8-6-3-1-5(2-4-6)7(9)10/h1-4,8H,(H,9,10)
InChI Key	FJKROLUGYXJWQN-UHFFFAOYSA-N
Melting Point	213-217 °C (lit.)
Flash Point	199°C
Purity	98%
Density	1.46 g/ml
Solubility	0.04 M;5 mg/mL at 25 °C;Solubility (in 100 g of solution): 99% ethanol 38.75 g (67 °C); n-butanol 19.5 g (32.5 °C);Soluble in about 125 parts water, freely in alcohol, slightly in chloroform; soluble in ether, acetone. Practically insoluble in carbon disulfide.;In water, 5000 mg/L at 25 °C;5.0 mg/mL;slightly soluble in water; soluble in organic solvents;freely soluble (in ethanol)
Appearance	Solid
Application	4-Hydroxybenzoic Acid, also known as PHBA, serves multiple purposes across various industries due to its unique chemical properties. Primarily, it functions as a crucial intermediate in the synthesis of dyes, antiseptics, and active pharmaceutical ingredients. The acid's esters, commonly referred to as parabens, are extensively employed as preservatives in cosmetics and certain ophthalmic solutions. Moreover, it is applied as a food preservative, corrosion inhibitor, antioxidant, and emulsifier. In the realm of materials science, 4-hydroxybenzoic acid is integral to the creation of Vectran fiber through its reaction with 6-hydroxynaphthalene-2-carboxylic acid, resulting in an aromatic polyester. It is also a precursor in manufacturing compounds such as p-hydroxyphenylbenzoate, p-acetoxybenzoyl chloride, and 4,4'-dihydroxybenzophenone. Additionally, it finds applications in paint and coating additives, processing aids, and various electrical and electronic products. Through its diverse uses, 4-hydroxybenzoic acid plays a significant role in enhancing the functionality and longevity of numerous products.
Active Content	95%
EC Number	202-804-9
pH	3.3 (1g/L, H₂O)
pKa	4.48
Refractive Index	1.53
Solubility in Water	5 g/L
Vapor Pressure	1.92e-07 mmHg;1.9X10-7 mm Hg at 25 °C /Extrapolated/