The present invention is directed to a pneumatic tire with a built-in sealant layer composite where the composite is composed of polyurethane with a thin layer of at least one of particulate filler, short fibers and non-woven microfiber. In one embodiment, said polyurethane sealant composite is comprised of a plurality of circumferentially extending layers comprised of a first polyurethane sealant layer, a second polyurethane sealant layer and a thin layer of polyurethane sealant-containing non-woven microfiber positioned between said first and second polyurethane layers. In another embodiment, said polyurethane sealant is a composite comprised of a polyurethane sealant layer containing a thin layer of at least one of particulate filler and short fibers.