乙烯基酯，又称乙烯基酯，是由环氧树脂与不饱和一元羧酸的酯化反应产生的树脂。然后反应产物会在可进行反应的溶剂中溶解以反应，例如苯乙烯，其含量约占总重量的35 - 45％。 它可以用来代替树酯或是环氧树酯的基质的合成材料，其优点在于它的体积介于聚酯和环氧树脂之间的中间。乙烯基酯树脂的粘度（约200cps）相较于聚酯（约500cps）和环氧树脂（约900cps）来说是比较低的。 在自制飞机上，Glasair和Glastar的飞机借由乙烯基酯增强玻璃纤维结构进行了广泛的使用。根据BS4994，此树酯也可以应用在海洋产业上，由于其高耐腐蚀性和高防水能力。乙烯基酯脂广泛用于制造玻璃钢储罐和容器。

Vinyl Ester, or Vinylester, is a resin produced by the esterification of an epoxy resin with an unsaturated monocarboxylic acid. The reaction product is then dissolved in a reactive solvent, such as styrene, to a 35–45 percent content by weight.

It can be used as an alternative to polyester and epoxy materials in matrix or composite materials, where its characteristics, strengths, and bulk cost intermediate between polyester and epoxy. Vinyl ester has lower resin viscosity (approx 200 cps) than polyester (approx 500cps) and epoxy (approx 900cps).