Polyurethane is any polymer consisting of a chain of repeating organic units joined by urethane linkages. Polyurethane polymers are formed through step-growth polymerization by making a monomer containing at least two isocyanate functional groups to react with another monomer containing at least two hydroxyl (alcohol) groups. This article provides a detailed account of the protective coatings used in the building, infrastructure, and architectural markets. It focuses on the various types of polyurethane coatings used in these applications: moisture-cure and two-pack aromatic coatings as primers and topcoats, moisture-cure aromatic elastomeric high-build coatings, moisture-cure aliphatic topcoats, two-pack aliphatic polyurethane coatings as topcoats, and one- and two-pack polyurethane dispersion coatings as sealers and topcoats. It also includes a section on the health effects of isocyanates.

This article describes the coating materials, surface-preparation requirements, and application techniques used to protect underground pipelines. It provides a valuable insight into the types of polymer-based coatings that are both cost-effective and widely accepted in the pipeline industry.

This article provides an overview of curing techniques, adhesive chemistries, surface preparation, adhesive selection, and medical applications of adhesives. The curing techniques are classified into moisture, irradiation, heat, and anaerobic. The article highlights the common types of curable adhesives used for medical device assemblies, including acrylics, cyanoacrylates, epoxies, urethanes, and silicones. Other forms of adhesives, such as hot melts, bioadhesives, and pressure-sensitive adhesives, are also discussed. The typical characteristics and applications of biocompatible medical device adhesives are listed in a table. The article concludes with a section on the selection of materials for medical adhesives.

No-bake sand molds are based on the curing of inorganic or organic binders with either gaseous catalysts or liquid catalysts. This article reviews the major aspects of no-bake sand bonding in terms of coremaking, molding methods, and sand processing. It discusses the points to be noted in handling sand-resin mixtures for no-bake molds or cones and lists some advantages of no-bake air-set cores and molds. The article describes the process procedures, advantages, and disadvantages of gas curing and air-setting hardening of sodium silicates. It examines the members of the air-setting organic binders, namely, furan no-bake resins, phenolic no-bake resins, and urethanes. The article provides an overview of gas-cured organic binders. It also illustrates the three commercial systems for sand reclamation: wet reclamation systems, dry reclamation systems, and thermal reclamation.