Preparation, characterization, and applications of polyurea foams

The pursuit of effective protective structures has been at the forefront in the past twodecades following the fallout from the severe consequences of concussions during American football, requiring innovations in materials to absorb energy efficiently. As a result, polyurea foams were produced since the base material was previously shown to exhibit superior mechanical and impact mitigation properties. In this chapter, a brief historical background leads to a summary of the research done over the past twodecades involving the experimental investigations of polyurea foams under a wide range of strain rates. The ongoing research on polyurea elastomers serves as the motivation for producing foams from this material. First, two different foaming approaches are presented based on recent reports in the literature. Next, the quasi-static and dynamic properties of polyurea foams are briefly discussed, presenting two current applications in football helmets and orthotics. The chapter ends with a perspective of future research directions on polyurea foams.