PIB 4H Polyisobutylene Rit-Chem Plasticizers >> Polyisobutylene (PIB) ADHESIVE >> Hot-melt SEALANT ADHESIVE >> Solvent based Polyisobutylene - Low molecular weight hydrocarbon polymer for use in hot melt and solvent-based adhesive and sealant applications. Polyisobutylene. Possesses low molecular weight. Used in hot melt and solvent-based adhesive and sealant applications.