Introduction to waterborne polyurethanes

Abstract

Polyurethanes (PUs) are one of the most diverse categories of polymers. They are available in different forms, such as adhesives, coatings, elastomers, and foams. PUs have unique properties such as desired mechanical, chemical, and abrasion resistance properties. But one of the disadvantages of typical PUs is using organic solvents, which are harmful to human health and the environment. In this regard, the researchers introduced and developed an environmentally friendly alternative to solvent-based PUs, called waterborne polyurethanes (WBPUs). WBPUs, without or with little volatile organic compounds (VOCs), can form thin films with excellent adhesion on many substrates, including metal, glass, and wood at room temperature. Other characteristics of WBPUs are low viscosity, non-toxicity, nonflammability, and cost-effectiveness. Due to the non-dissolution of typical PUs in water, it is necessary to use specific strategies to disperse them in water, by using various processes and raw materials. In this chapter, after an introduction to waterborne polyurethanes, their structure, required raw materials, synthesis methods, and various applications are discussed. In the end, the challenges of this type of polyurethanes are addressed, especially in the preparation process and their industrialization. © 2023 Nova Science Publishers, Inc.