Methyl tetrahydrophthalic anhydride (MTHPA
, MeTHPA) is a chemical substance that is used in the processing of some materials. Some common curing agents have the use of methyl tetrahydrophthalic anhydride(MTHPA, MeTHPA). Nowadays, with the development of society, the use of hydrophthalic anhydride is also increasing.
, referred to as MTHPA, MeTHPA, has two isomers, namely 4-methyltetrahydrophthalic anhydride and 3-methyltetrahydrophthalic anhydride, having a melting point of 65°C and 63°C. It is rarely used as a curing agent alone. The actual commodity is a liquid mixture that isomerized to various isomers. The molecular weight is 166.17, and light yellow color, transparent oily liquid, relative density of 1.20 - 1.22. Freezing point < -20°C. The boiling point is 115-155°C. Viscosity (25°C) 40 - 80 mPa · s. The refractive index is 1.4960 to 1.4980. The anhydride group content is ≥ 40%. The neutralization equivalent is 81-85. The flash point is 137 - 150°C. Soluble in acetone, ethanol, toluene, etc. It has good stability in air and is not easy to precipitate crystals. Low toxicity, LD502102mg/kg.
Gas Chromatography and Liquid Chromatography Analysis Objects: Gas chromatography mainly analyzes stationary phases and gases. Liquid chromatography mainly analyzes liquids. Gas chromatography can be divided into gas-solid chromatography and gas-liquid chromatography. Gas-solid chromatography refers to a chromatographic separation method in which the mobile phase is a gas and the stationary phase is a solid material. For example, activated carbon, silica gel or the like is used as a stationary phase.
Methyl tetrahydrophthalic anhydride(MTHPA, MeTHPA) is the product of the hydrogenation of MeTHPA. As described above, MeTHPA
has different isomers, so the commercial MeHHPA also differs slightly in performance depending on the manufacturer.
From the characteristic data of curing of different formula casts, it can be seen that the component uses alicyclic epoxy MTHPA (MeTHPA) or MeHHPA curing agent, and has higher heat distortion temperature; HHPA is used in the component, or MeHHPA, or alicyclic epoxy methyl tetrahydrophthalic anhydride, has a lower dielectric constant and dielectric loss tangent at high temperatures. All of these indicate that the double bond in methyl tetrahydrophthalic anhydride (MTHPA, MeTHPA) or curing agent has a certain influence on the properties of the cured product.