Enhanced Dynamic Performance and Mechanical Reinforcement of Polyurea Coatings With Surface‐Modified Graphene Platelets

ABSTRACT Studying structural dynamics of polyurea (PU) is pivotal to analyze its vibration‐damping features. In this study, a graphene‐reinforced PU coating with enhanced mechanical and damping properties was developed. PU nanocomposite coating was reinforced with pristine graphene platelets (GNPs) and isophorone diamine (IPDA)‐modified GNPs (m‐GNPs) via in situ polymerization. Morphological characterization confirmed surface modification of GNPs with IPDA showing better dispersion within the PU matrix; this led to a strong interface between m‐GNPs and the PU matrix. The optimal mechanical and structural dynamic properties were achieved at only 0.1 wt% of m‐GNPs; the tensile strength of PU/m‐GNPs increased by 35% while the increment for pristine GNPs was only 11%. The vibration damping—evaluated by loss factor—improved for all four frequency modes; the loss factor increased across all four modes by 26.9%, 88.0%, 158.3%, and 5.0%, respectively. Moreover, a noise reduction of 33.1 dB was attained with PU/m‐GNPs compared to the bare aluminum. The improvements are associated with an effective friction and scattering mechanism, facilitated by an excellent filler‐matrix interface that reduces vibrations and sound waves. Additionally, finite element analysis was implemented to develop a model that describes dynamic responses of PU/m‐GnP composites; the model was validated, which is in accord with the experimental measurements. These findings highlight the potential of GNPs‐enhanced PU coatings as an effective solution for structural vibration damping and acoustic attenuation across diverse industrial applications.