Thermal Analysis of Polyurethane Dispersions Based on Different Polyols

Abstract

Water-based polyurethane dispersions (PUD) are a rapidly growing segment of polyurethane (PU) coatings industry due to environmental legislations such as the clean air act and also due to technological advances that made them an effective substitute for the solvent-based analogs. Water-based or waterborne PUD have gained increasing importance in a range of applications, due in large part to properties such as adhesion to a range of substrates, resistance to chemicals, solvents and water, abrasion resistance and flexibility. Water-based PUD show very good mechanical and chemical properties and match the regulatory pressures for low volatile organic compound (VOC) containing raw paints. The continuous reduction in costs and the control of VOC emissions are increasing the use of water-based resins, motivating the development of PU dispersed in water. PU obtained from water-based PUD have superior properties when compared with similar materials obtained from organic media. Water-based PUD are used in many application areas to coat a wide range of substrates for example footwear adhesives, wood lacquers for flooring and furniture, leather finishings, plastic coatings, printing inks and automotive base coats (Rothause et al., 1987; Kim et al., 1994; Ramesh et al., 1994).