Abstract: A low density polymer composition including a polymer component capable of being cured, a low density filler in an amount sufficient to reduce the density of the polymer and a thixotrope present in a sufficient amount to impart a sufficient viscosity and to inhibit separation of the filler from the polymer until after the polymer is cured. The resulting lightweight, filled polymer composition is a strong electrical insulator, has low shrinkage, a low coefficient of thermal expansion, low cured density and a soft filler that does not harden the polymer. Methods of preparing and using the low density polymer compositions are also disclosed.

Abstract: The present invention relates to ion exchange membranes comprising soluble graft copolymer comprising a backbone of a first polymer having a main chain containing aromatic rings and a polymerizable vinyl or ring containing compound which contains at least one functional group which displays ion exchange functionality or may be converted to display ion exchange functionality, which is grafted onto said first polymer on at least one of said aromatic rings or on at least one benzylic carbon atom of said aromatic rings. The copolymer components may be selected to produce membranes for a variety of uses including electrodialytic processes such as electrodialytic concentration and separation processes, electrodialytic water splitting, electrolysis or electrolytic splitting of water and fuel cells for electrical generation; and pressure or chemical potential driven membrane processes such as ultrafiltration, reverse osmosis, piezodialysis, diffusion dialysis and pervaporation.