Pentaerythritol Triacrylate (PETA)

Commercially available PETA is typically a mixture of the tri- and tetra-acrylate esters of pentaerythritol, with functionality ranging from 3 to 4. Pure PETA has three acrylate groups; PETRA has four. The mixed product offers a balance: lower viscosity than pure PETRA while achieving high crosslink density. Formulators choose higher PETRA content (quad-functional) for maximum hardcoat performance, and higher PETA content for a small reduction in brittleness.