Nanocomposite Foams of Polyurethane with Carbon Nanoparticles—Design and Competence towards Shape Memory, Electromagnetic Interference (EMI) Shielding, and Biomedical Fields

Abstract

Polyurethane is a multipurpose polymer with indispensable physical characteristics and technical uses, such as films/coatings, fibers, and foams. The inclusion of nanoparticles in the polyurethane matrix has further enhanced the properties and potential of this important polymer. Research in this field has led to the design and exploration of polyurethane foams and polyurethane nanocomposite foams. This review article reflects vital aspects related to the fabrication, features, and applications of polyurethane nanocomposite foams. High-performance nanocellular polyurethanes have been produced using carbon nanoparticles such as graphene and carbon nanotubes. Enhancing the amounts of nanofillers led to overall improved nanocomposite foam features and performances. Subsequently, polyurethane nanocomposite foams showed exceptional morphology, electrical conductivity, mechanical strength, thermal stability, and other physical properties. Consequently, multifunctional applications of polyurethane nanocomposite foams have been observed in shape memory, electromagnetic interference shielding, and biomedical applications.

Recent Trends in Polymeric Foams and Porous Structures for Electromagnetic Interference Shielding Applications

“…Additionally, in the specific case of EMI shielding, the generation of a controlled cellular structure, especially of the microcellular type, promotes the absorption/multiple reflection-based EMI shielding mechanism. In doing so, the common problem concerning EMI shielding components based on reflective materials (such as metals), and the manner in which they interfere with the reflected waves and surrounding electronic components, is mitigated [ 3 , 5 , 6 ]. In sum, combining the addition of conductive nanofillers with polymers, and generating a controlled cellular/porous structure, enables the creation of lightweight components with enhanced electrical conductivities and EMI shielding properties.…”

Recent Trends on Polymeric Foams and Porous Structures for Emi Shielding Applications

“…Not only foaming leads to even lighter structures, with direct advantages in fields such as aerospace, and enhanced functional characteristics such as reduced thermal conductivity, but it has also been proved to effectively reduce the percolation threshold of the conductive nanofillers, enabling to obtain lightweight components with high electrical conductivities at lower concentrations of nanofiller. Additionally, in the specific case of EMI shielding, the generation of a controlled cellular structure, especially of the microcellular type, promotes an absorption/multiple reflection-based EMI shielding mechanism, this way reducing the common problem of EMI shielding components based on reflective materials (such as metals) related to the interference of the reflected waves with surrounding electronic components [3,[5][6]. Summarizing, the combination of the addition of conductive nanofillers to polymers and generation of a controlled cellular/porous structure enables to create lightweight components with enhanced electrical conductivities and EMI shielding properties.…”