Acrylic/urethane hybrid liquid encapsulants for photovoltaic modules

A 100% solid, curable liquid encapsulant for photovoltaic modules was developed using acrylic/urethane hybrid chemistry. These liquid acrylics are easily coated and cured with polyisocyanates to form rubbery solids with tunable cure time, excellent optical properties, and UV stability for over 5000h of accelerated aging. Adhesion to a variety of substrates was good and remained high after aging as well. A variety of catalysts can be used for the curing reaction to tune pot life and cure time. The dielectric strength, surface resistivity, and volume resistivity are similar to commercial encapsulants, and the water vapor transmission rate is lower than EVA. The materials described herein are also useful as optically clear adhesives and potting agents. •A novel acrylic-urethane hybrid material was developed as a liquid photovoltaic encapsulant.•The pot life and cure time are tunable with catalyst type and level.•The material is resistant to yellowing and haze after exposure to accelerated UV aging conditions.