Dimethyl Isophthalate (DMI) CAS 1459-93-4

FAQ - Technical & Supply Chain

• Q:

  What is Dimethyl Isophthalate DMI CAS 1459-93-4?

  A: Dimethyl Isophthalate, commonly abbreviated DMI, is an aromatic diester also called dimethyl m-phthalate or dimethyl benzene-1,3-dicarboxylate. It is used mainly as an isophthalate intermediate or comonomer in polyester and resin manufacture.
• Q:

  How does DMI differ from Dimethyl Terephthalate and dimethyl phthalate?

  A: DMI is the meta-isomer and introduces an isophthalate unit, while Dimethyl Terephthalate introduces a terephthalate unit and dimethyl phthalate is the ortho-isomer. The three esters are not interchangeable because their different ring positions change polymer structure and performance.
• Q:

  What are the main applications of Dimethyl Isophthalate?

  A: DMI is used in polyester resins, specialty copolyesters and polyester films where an isophthalate component modifies crystallization behaviour, clarity, flexibility and heat resistance. It also appears in polyacrylate intermediates, engineering plastics and selected plasticizer syntheses.
• Q:

  Why is DMI used as a polyester modifier?

  A: The meta arrangement of the ester groups disrupts regular chain packing, which can reduce crystallinity and improve clarity or processability in the final polymer. This makes DMI useful for bottle resins, films and engineering plastics requiring controlled crystallization.
• Q:

  What physical form and typical properties should be expected?

  A: DMI is normally supplied as a white crystalline flake or powder with a melting point around 66-69 C and density near 1.15 g/cm3. It is only slightly soluble in water and more soluble in common organic solvents, so it should be kept dry and stored in closed packaging.