trimellitate

Trimellitate refers to esters of trimellitic acid (benzene-1,2,4-tricarboxylic acid). They are typically triesters in which all three carboxyl groups are esterified with alcohols. Commercial trimellitates are produced by esterification of trimellitic acid or trimellitic anhydride with alcohols such as branched C8–C10 alcohols.

These compounds have high molecular weight, high boiling points, and low volatility, and they generally show good compatibility with polyvinyl chloride (PVC) and other polymers. They are valued for their ability to impart flexibility while maintaining heat resistance, and for relatively low migration compared with some other plasticizers.

Uses of trimellitate esters are primarily as plasticizers for PVC and other polymers. They are chosen for high temperature performance, low extraction, and suitable electrical insulation properties, making them common in cables, films, coatings, and flexible plastics used in automotive, electrical, and consumer applications. The most widely discussed trimellitate plasticizers include tri(2-ethylhexyl) trimellitate and related high‑molecular‑weight esters.

Safety and environmental aspects: Trimellitic acid anhydride and related compounds can be irritants or sensitizers, and the handling of trimellitate esters should follow standard chemical hygiene practices. As plasticizers, trimellitates may migrate from products under certain conditions, raising exposure considerations. Regulatory approaches in various regions have focused on phthalates, promoting trimellitate or other alternatives with lower volatility and migration potential. Life-cycle and environmental fate depend on the specific ester composition.

See also: plasticizer, phthalate substitute, polyvinyl chloride, TOTM.