Pyrolysis and fire behaviour of epoxy systems containing a novel 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-(DOPO)-based diamino hardener

A New Halogen‐Free Flame Retardant Based on 9,10‐Dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide for Epoxy Resins and their Carbon Fiber Composites for the Automotive and Aviation Industries

“…DOPI is supposed to act in the gas phase. [6] The release of phosphorus in the gas phase, proven in evolved gas analysis, is possible. In both RTM6 þ DOPI and RTM6-CF þ DOPI a condensed phase mechanism due to the enhanced amount of residue in thermogravimetry and a gas phase mechanism due to the presence of phosphorus in the gas phase monitored in evolved gas analysis are expected.…”

“…Many derivatives of DOPO, either as a reactive hardener or a non-reactive additive, combined with other additives or directly incorporated in the epoxy matrix, have already been synthesized. [6][7][8][9][10][11][12] These DOPO derivatives can act in the gas phase through flame inhibition, in the condensed phase through charring, or through both mechanisms at the same time. [6,13,14] Since the epoxy resins that are currently commercially available for resin transfer molding applications in the automotive and aviation industries have remarkable drawbacks, especially with respect to their fire behavior, the pyrolysis and burning behavior of a novel DOPO-based non-reactive flame retardant incorporated in two different epoxy systems suitable either for the automotive industry or for the aviation industry were investigated.…”

Synthesis of a novel PEPA-substituted polyphosphoramide with high char residues and its performance as an intumescent flame retardant for epoxy resins

“…To overcome these problems, covalently incorporating flame retardant groups to the backbones of EP and additive-type polymeric flame retardants are recognized to be highly effective approaches [17]. The chemical incorporation of phosphorus into the backbones of EP are more preferred because they show less negative effects on physical properties and glass transition temperature (T g ) [18,19]. For instance, Schartel [20,21] have compared various phosphorus-containing hardeners incorporated in both epoxy resins and composites, and observed clear tendencies according to the oxidation state.…”

Synthesis of a novel phosphorus-containing epoxy curing agent and the thermal, mechanical and flame-retardant properties of the cured products

“…However, a variety of problems like poor compatibility, leaching over time and deterioration in mechanical properties occurred [14]. Therefore, more studies have been attributed to incorporating phosphorus-containing flame units into the macromolecular backbone and side chains [15], which is a much more effective way to introduce a sustainable flame resistance as well as maintain the original physical properties of the epoxy resins [16,17]. For example, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO) has been widely investigated, since P-H bonds in the DOPO can react with some functional groups such as epoxide group, C=N and C=C groups etc.…”