bis2hydroxyethyl

Bis(2-hydroxyethyl) is a chemical descriptor used in organic and polymer chemistry to indicate two hydroxyethyl substituents. Each hydroxyethyl group is a two-carbon fragment (–CH2–CH2–OH) attached to a central moiety. The phrase appears in systematic and common names for diol-containing compounds, often in the form bis(2-hydroxyethyl) X, where X represents a difunctional core such as an aromatic ring, a diacid, or another chemical group.

In naming, the prefix bis(2-hydroxyethyl) signals that two identical hydroxyethyl groups are present. These groups impart difunctionality and hydrophilicity to the molecule, enabling further chemical reactions such as esterification, ether formation, or polyurethane and polyester formation. The two terminal hydroxyl groups make the molecule a diol, capable of acting as a chain extender or crosslinker in polymer synthesis.

A well-known example is bis(2-hydroxyethyl) terephthalate, commonly abbreviated BHET. BHET is the diester of terephthalic acid with ethylene glycol and serves as an intermediate in polyester chemistry and PET production and recycling pathways. The structure features two ester linkages to the terephthalate moiety and two terminal hydroxyl groups, enabling further polymerization or chemical modification.

Other bis(2-hydroxyethyl) derivatives are encountered in specialty polyesters and crosslinking agents, where the motif provides two reactive hydroxyl sites linked through a flexible, hydrophilic ethylene bridge. Overall, bis(2-hydroxyethyl) compounds are valued for their difunctionality and versatility in forming polyesters, polyurethanes, and related materials.