Hydroxypivalic acid
CAS Number
4835-90-9
EC Number
225-419-8
Abbreviation
HPA
What is Hydroxypivalic acid?
Hydroxypivalic acid (CAS 4835-90-9), commonly abbreviated as HPA, is a bifunctional organic acid used as a reactive building block in polymer synthesis and resin formulation. Also known as oxypivalic acid.
Where is Hydroxypivalic acid used?
- Coatings: hydroxyl-functional polyester resins that crosslink with isocyanates or melamines, improving hardness and weatherability in automotive and industrial finishes
- Alkyd resins: molecular weight control and branching, influencing viscosity and drying performance
- Adhesives and sealants: HPA-derived polyesters for flexibility and adhesion
- Pharmaceuticals: chiral intermediate and building block for active pharmaceutical ingredient synthesis
- Its hydroxyl and carboxyl groups make it a practical monomer for specialty polyesters and alkyd resins.
Commercial specifications
- Pharmaceutical-grade material where API synthesis requires tighter purity specifications
- Packaging from small drums to bulk quantities
Other Names (Synonyms)
α,α-Dimethyl-β-hydroxypropionic acid|Oxypivalic acid|3-Hydroxy-2,2-dimethylpropanoic acid|2,2-Dimethylhydracrylic acid|2,2-Dimethyl-3-hydroxypropionic acid|2,2-Dimethyl-3-hydroxypropanoic acid|3-Hydroxy-2,2-dimethylpropionic acid|Propanoic acid, 3-hydroxy-2,2-dimethyl-|HPA
What are the physical properties of Hydroxypivalic acid?
Melting Point 124 °C
Boiling Point 156-159 °C @ Press: 25 Torr
Density 1.221 g/mL at 25 °C(lit.)
Flash Point >230 °F
Color White to Almost white
Form powder to crystal
Water Solubility Soluble in water.
Vapor Pressure 0.446Pa at 25℃
Refractive Index n 20/D 1.5215(lit.)
Log P -0.02
How is Hydroxypivalic acid classified and handled safely? Learn More
Danger
GHS05· Corrosive GHS07· Irritant
Hazard Statements
H315 Causes skin irritation
H318 Causes serious eye damage
H335 May cause respiratory irritation
Precautionary Statements
P261 Avoid breathing dust/fume/gas/mist/vapours/spray.
P264 Wash … thoroughly after handling.
P271 Use only outdoors or in a well-ventilated area.
P280 Wear protective gloves/protective clothing/eye protection/face protection.
Which trade and regulatory codes apply to Hydroxypivalic acid?
HS Code 2918.19.9000
WGK (Germany) 1