Epoxy Compositions with Reduced Flammability Based on DER-354 Resin and a Curing Agent Containing Aminophosphazenes Synthesized in Bulk Isophoronediamine

Abstract

A method for the synthesis of an amine-containing epoxy resin curing agent by dissolving hexakis-[(4-formyl)phenoxy]cyclotriphosphazene in an excess of isophoronediamine was developed. The curing agent was characterized via NMR and IR spectroscopy and MALDI-TOF mass spectrometry, and its rheological characteristics were studied. Compositions based on DER-354 epoxy resin and the synthesized curing agent with different amounts of phosphazene content were obtained. The rheological characteristics of these compositions were studied, followed by their curing. An improvement in several thermal (DSC), mechanical (compression, tension, and adhesion), and physicochemical (water absorption and water solubility) characteristics, as well as the fire resistance of the obtained materials modified with phosphazene, was observed, compared with unmodified samples. In particular, there was an improvement in adhesive characteristics and fire resistance. Thus, compositions based on a curing agent containing a 30% modifier were shown to fulfill the V-1 fire resistance category. The developed compositions can be processed by contact molding, winding, and resin transfer molding (RTM), and the resulting material is suitable for use in aircraft, automotive products, design applications, and home repairs.

Optimized Functionalization of Graphene Oxide for Enhanced Mechanical Properties in Epoxy Resin Composites

“…Simultaneously, researchers have explored altering the structure of the curing agent, a pursuit that has garnered considerable interest. For instance, Alexey Orlov et al [9] undertook the synthesis of curing agents featuring varying phosphazene contents. Their investigations revealed that the complex comprising 30% modifier significantly enhanced both the mechanical robustness and fireretardant properties of the epoxy resin.…”

The Effect of Alkyl Terminal Chain Length of Schiff-Based Cyclotriphosphazene Derivatives towards Epoxy Resins on Flame Retardancy and Mechanical Properties

“…At present, an approach to overcome these issues is using alternative free-halogen FR such as hexasubstituted cyclotriphosphazene derived from a well-known FR agent, which is HCCP [ 13 , 14 , 15 ]. HCCP is commonly used as starting material for the synthesis, because the presence of a reactive P-Cl bond makes it eligible to undergo nucleophilic substitution [ 16 ].…”

Synthesis of multi‐element hybrid polyphosphonitrile microspheres and their flame retardant application in epoxy resins

“…Compared with the known phosphonitrile-based flame retardant epoxy resin, this paper selects the metal and phosphonitrile synergistic system, the metal is dispersed in the form of coordination bond in the polyphosphonitrile, and the dispersive effect with the flame retardant is good, so as to achieve the ideal synergistic flame retardant effect. [25][26][27] The surface morphology, chemical structure, and elemental analysis was carried out using electron microscopy (SEM-EDS), infrared spectroscopy (FTIR), and x-ray photoelectron spectroscopy (XPS). The mechanical properties of Salen-PZN-Ni@BA@KH-550/ EP composites were investigated by tensile, impact, flexural and hardness tests.…”