Tetrahydrophthalic anhydride
CAS Number
85-43-8
EC Number
201-605-4
Abbreviation
THPA
What is Tetrahydrophthalic anhydride?
Tetrahydrophthalic anhydride (CAS 85-43-8), commonly abbreviated as THPA, is a cyclic dicarboxylic anhydride used as a curing agent and reactive intermediate in polymer manufacturing.
Where is Tetrahydrophthalic anhydride used?
- Coatings: hardener for epoxy systems, stoichiometric curing agent producing crosslinked networks with mechanical performance and chemical resistance
- Adhesives and sealants: THPA-cured epoxy formulations deliver bond strength and thermal stability for structural and assembly applications
- Plastics: building block for polyester and alkyd resins
- Alkyd and unsaturated polyester resin producers use it as a monomer to control flexibility and reactivity.
Commercial specifications
- Technical grade, purity typically 98% or above
- Bulk supply in bags or drums, packaging scaled to industrial procurement volumes
Other Names (Synonyms)
3a,4,7,7a-tetrahydroisobenzofuran-1,3-quinone|3a,4,7,7a-tetrahydro-2-benzofuran-1,3-dione|1,2,3,6-tetrahydrophthalic anhydride|Rikacid TH|Tetrahydrophthalic acid anhydride|Memtetrahydro phtalic anhydride|4-Cyclohexene-1,2-dicarboxylic acid anhydride|1,3-Isobenzofurandione, 3a,4,7,7a-tetrahydro-|THPA
What are the physical properties of Tetrahydrophthalic anhydride?
Melting Point 102 °C
Boiling Point 195 °C @ Press: 50 Torr
Density 1.20 g/cm³ @ Temp: 105 °C
Flash Point 157°C
Color Off-White to Light Tan
Form Solid
Water Solubility 29.4g/L at 20℃
Vapor Pressure 0.021Pa at 20℃
Refractive Index 1.4810 (estimate)
pH 2.1 (20°C, 10g/L in H2O)
Log P 1.29 at 40℃
How is Tetrahydrophthalic anhydride classified and handled safely? Learn More
Danger
GHS05· Corrosive GHS08· Health Hazard GHS07· Irritant
Hazard Statements
H302 Harmful if swallowed
H315 Causes skin irritation
H317 May cause an allergic skin reaction
H318 Causes serious eye damage
Precautionary Statements
P233 Keep container tightly closed.
P260 Do not breathe dust/fume/gas/mist/vapours/spray.
P261 Avoid breathing dust/fume/gas/mist/vapours/spray.
P264 Wash … thoroughly after handling.