PU FOAM is a polyurethanepolymer that reacts with moisture in the air causing it to expand to fill any shaped hole or cavity.T esealant/Whixpandable pu foam te expanding foam sealant PU Waterproof spray foam sealant he cured foam can be cut or shaped and painted as disired. It is used preferably for insulation and installation in the construction sector application can be filling cavities, break-throughs, cracks and gaps, sound and heat insulation bonding fixing mounting, etc.
The pioneering work on polyurethanes was conducted by Otto Bayer and his coworkers in 1937 in Germany. Polyurethane foams, including SPF upholstery (flexibile) foams, etc. were developed in the 1950's.