Preparation and evaluation of Urea‐F amine crosslinkers.

This study presents the preparation of a long‐chain amine solution, employing the concept of urea‐formaldehyde synthesis. We also investigate the performance shifts in the cured product post‐urea addition. The Urea‐F curing agent is prepared by reacting EDA/DETA/TETA/TEPA, formaldehyde, and urea, and crosslinked with bisphenol A epoxy resin (E51). The crosslinking agent solves the problem of urea not being suitable for curing epoxy resin, and it improves the problem of low mechanical strength of traditional amine crosslinked epoxy resin cured materials. The cured product underwent evaluation through acid and alkali resistance solution measurement and mechanical and thermal tests. The results show enhanced heat resistance in the cured product, with its maximum thermal decomposition rate exceeding 350°C. The cured products have better mechanical properties than the amine monomers, with enhanced bending strength and superior acid–base solution resistance. The scanning electron microscopy micrograph indicates that the cured product fractures have a tight internal structure. [ABSTRACT FROM AUTHOR]