Moisture crosslinking process for foamed polymers

Abstract Alkoxysilanes can be grafted onto an ethylene homopolymer or copolymer to give a moisture crosslinkable polymer. Moisture crosslinking has many benefits over peroxide‐ or irradiation‐induced crosslinking. Simple, conventional equipment allows processing with lower capital investment and less manufacturing space. The moisture crosslinking process permits conventional thermoplastic processing after the initial grafting process to give greater flexibility in the types of applications for this crosslinking technique. In foaming processes, silane crosslinking is compatible with most types of conventional blowing agents and other additives. The combination of silane crosslinking with metallocene polyethylene technology has given rise to a broad range of crosslinked polyolefin materials, including flexible, rigid, open, and closed cell foams. Good quality foams with very low densities, approaching 1 lb/ft 3 (16 kg/m 3 ), are possible. The advantages of silane crosslinking technology have opened many new markets for polyethylene foams.