Studying the Effect of Zinc 3-(Dibutylamino) Propionate (ZDAP) Additive on Fire Retardant, Mechanical, and Physical Characteristics of Epoxy-Amine Networks

Epoxy-amine networks are useful as structural materials but are inherently flammable. To enhance the fire performance of epoxy-amine, Nazarenko research group developed zinc 3-(dibutylamino)propionate (ZDAP) as a fire-retardant additive. This zinc-salt-based fire retardant is an endothermically-degrading char former that is functionalized with tertiary amines that allow for its dissolution in epoxy-amine. As a result, ZDAP-loaded EANs showed improved fire performance. The char of these samples was analyzed with SEM/EDX and WAXs showing that ZDAP was degrading to ZnO char in a two-step breakdown. My research has found that the epoxy-amine composite Epon 828-Jeffamine D230 when loaded 15 wt/wt% ZDAP had its peak rate of heat release reduced by 38%. Furthermore, at loads of less than 20 wt/wt% ZDAP, the Young’s moduli of the composites were all within 10% of neat samples according to tensile testing and 8% for extensometry. ZDAP acted as a plasticizer whose inclusion in EAN yielded at lower strains, faster stress-relaxation, thinner necking, and lower glass transition temperatures. The effects of ZDAP synthetic method and purity on fire and mechanical performance were also assayed. It was found that reactive extrusion can produce low-quality (~80% purity) material that is effective for improving fire performance, but produces brittle material as compared with benchtop-synthesized ZDAP of ~94% purity.