Dimethyl isophthalate

Chemical properties

white to off-white flakes or crystalline powder. Soluble in methanol, ethanol, insoluble in water, used in organic synthesis, as a fixed plate for gas chromatography.

The Uses of Dimethyl isophthalate

Dimethyl isophthalate is used as a plasticizer, to make polyester resins, as a polyacrylate resin comonomer, and as a perfume fixative. It may be used as an internal standard for determining, dimethyl-tere-phthalate (DMtP), dimethyl-phthalate (DMP), diethyl phthalate (DEP) in soil samples and biosolids using gas-chromatography coupled to mass spectrometry (GC-MS). It may also be used as an analytical reference standard for the quantification of the analyte in complex matrices including plastics, cosmetics, and environmental samples using gas chromatography coupled to positive chemical ionization mass spectrometry (GC-CIMS).

What are the applications of Application

Dimethyl isophthalate was used in the synthesis of:
polybutylene isophthalate end-capped with N-ethyl-pentadecafluorooctanamide.
poly(ethylene terephthalate-co-isophthalate-co-5-tert-butylisophthalate) terpolyesters.
Polyesters containing sulfonate groups were prepared from dimethyl isophthalate, BD and 5SIPNa by the usual two-stage crystallization.

Preparation

Dimethyl isophthalate is synthesized by esterifying isophthalic acid with methanol: Isophthalic acid (1.66gm, 0.1mmol) in super dry methanol (60mL) containing 2-3 drops of concentrated H2SO4 (AR) was refluxed till it dissolved. Then, the reaction mixture was poured onto ice cold water, immediately a solid started separating from the clear solution. To this a solution of sodium bicarbonate was added till the effervescence seized. The ester thus obtained was filtered and washed with water for several times (M.P: 64-67°C).

Synthesis Reference(s)

Tetrahedron Letters, 33, p. 1959, 1992 DOI: 10.1016/0040-4039(92)88113-J

General Description

Dimethyl isophthalate is dimethyl phthalate ester based plasticizer.

Flammability and Explosibility

Non flammable