Polyester (unsaturated, cast) vs Vinyl ester

Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.

Polyester (unsaturated, cast) in fullVinyl ester in full← All materials
PropertyPolyester (unsaturated, cast)Vinyl esterDifference
Density1.2 g/cm³1.12 g/cm³Polyester (unsaturated, cast) — 7% higher
Young's modulus E3.2 GPa3.2 GPaidentical
Tensile strength55 MPa86 MPaVinyl ester — 56% higher
Glass transition Tg75 °C120 °CVinyl ester — 45 °C higher
  • Callister & Rethwisch, Materials Science and Engineering, 10th ed.
  • Ashland Derakane 411 epoxy vinyl ester resin datasheet

Typical room-temperature values for learning and preliminary design; grades vary widely and a supplier datasheet always overrides a textbook figure. Confirm against the datasheet before design work.