Novel Amine-Functionalized Phosphoryl Hydrazine Flame Retardants for Epoxy Resin Systems

Date of Award

2018

Degree Name

M.S. in Chemical Engineering

Department

Department of Chemical and Materials Engineering

Advisor/Chair

Advisor: Donald Klosterman

Abstract

A series of eight novel phosphoryl hydrazine compounds were evaluated for their effectiveness as co-curing flame retardants (FR) in an epoxy resin system. First, the FR compounds were systematically evaluated with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) for their behavior in pure form and when co-cured with epoxy. The phosphorous content was kept constant at 2.5 wt% for each formulation. Results showed that three of the FR compounds were able to cure with the epoxy, while the others were not. Incorporation into the network increased the onset temperature of the flame retardant action according to DSC results. Cured samples were also characterized with microscale combustion calorimetry (MCC). Three of the formulations showed excellent flame retardation, as indicated by a 30% reduction in total heat release and three times increase in char yield compared to the control sample (no flame retardant). It proved difficult to scale up the formulations to making resin plaques for further testing due to the release of gas bubbles not observed in prior work with smaller samples. Limited success was achieved with one compound, with which 4 inch x 4 inch cured resin plaques were produced for cone calorimeter testing. Cone calorimeter results indicated good char formation behavior, but only a minor reduction in peak heat release rate (HRR) compared to the control sample. Also, it exhibited a highly erratic char formation and gas/fire plume formation, which led to poor reproducibility in heat release measurements. The level of gas/fire plume formation was undesirably high, but the smoke release rate was much lower than the control. Despite an only minor reduction in peak HRR, the flame-retardant effects that were characterized for this compound showed promise in regards to the mechanism of flame retardancy and lowering of total heat release and total smoke release.

Keywords

Chemical Engineering, Materials Science, Phosphoryl Flame Retardants, Flame Retardants for Epoxy Resin Systems, Cone Calorimeter, Micro Combustion Calorimeter

Rights Statement

Copyright © 2018, author

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