Polyurethane Foam Coating Degradation: Mechanisms and Methods of Assessment and Prevention of Degradation

Polyurethane foam (PUF) is one of the polymers which in recent years has been most frequently used in many different industries. Polyurethane foam coatings used as thermal and sound insulation materials can also be employed as top coats in order to decorate or protect public premises such as hospitals, cinema halls and etc. The benefits of PUF coatings include light-weight building construction, very good thermal and sound insulation, excellent adhesion to diverse substrates, excellent mechanical properties, high tensile strength, resistance to elongation, resistance to impact, abrasion and cracking, direct applicability on the surface of different materials such as asphalt, concrete, metal, plastic and wood, the ability to re-coat the previously coated surfaces, quick, easy and complete cure at room temperature and improving the speed of construction. A few studies have been done in order to increase the service life of PUF and PUF coatings. In this review, the results of these studies on different types of PUF coating degradation mechanisms including chemical (oxidation, thermolysis, photolysis, pyrolysis, solvolysis, hydrolysis, aminolysis, glycolysis and etc.), physical, mechanical and biological mechanisms have been discussed. Also different assessment test methods of PUFs degradation included QUV chamber, prohesion chamber and triethylene phosphate effect which are reported and the obtained results are analyzed. Finally, different applicable methods such as antioxidants and light stabilizers are considered to improve PUF’s resistance against degradation.