Exploring Auxetic Properties of Polyurea Foams
Abstract
Exploring Auxetic Properties of Polyurea FoamsAbstractAuxetic materials have a negative Poisson~s ratio meaning that they expand laterally when stretched and get thinner when uniaxially compressed. This can lead to improved impact and damping properties as the material tends to flow into the vicinity of the impact rather than flowing away in the lateral direction. The aim of this proposal is to explore the auxetic properties of recently developed polyurea based UCLA foams that by virtue of their unique microstructure and low glass transition temperature already display superior impact properties compared to all commercially available viscoelastic" foams over a wide range of hot and coldtemperatures. Since the Poisson~s ratio of UCLA foams was never measured, it is not known i""f they are auxetic or not. Thus, the first task of this proposal will be to measure their Poisson~s ratio as a function of density."" Next, we will induce or enhance (if they are already auxetic) their auxetic property by subjecting them to two (a chemo-mechanical" and a thermo-mechanical) postfoaming treatments. The processed foams will be tested for impact and damping properties to inquire if further improvements in these properties can be attained by introducing the auxetic microstructure.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 01, 2017
- Source ID
- N000141712708
Entities
People
- Vijay Gupta
Organizations
- Office of Naval Research
- United States Navy
- University of California, Los Angeles