an “ all - in - one ” spacer and seal useful in insulating glass units is based on silane - functional , organic polymer which preferably has a low permeability technology . this chemically crosslinking flexible thermoset spacer and seal offers a solution to overcome the current shortfalls of commercially available thermoplastic spacer materials . when used as an edge - seal in an insulating glass unit , the cured product of the composition performs the functions of sealing , bonding , spacing , and desiccating .