Compositions suitable for use as encapsulants are described. The inventive compositions include a high molecular weight polymeric material, a curing agent, an inorganic compound, and a coupling agent. Optional elements include adhesion promoting agents, colorants, antioxidants, and UV absorbers. The compositions have desirable diffusivity properties, making them suitable for use in devices in which a substantial blocking of moisture ingress is desired, such as photovoltaic (PV) modules.
The United States Government has rights in this invention under Contract No. DE-AC36-99G010337 between the United States Department of Energy and the National Renewable Energy Laboratory, a Division of the Midwest Research Institute.