Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5190530 | Polymer | 2006 | 14 Pages |
Abstract
A systematic and comparative evaluation of the pyrolysis of halogen-free flame-retarded epoxy resins containing phosphine oxide, phosphinate, phosphonate, and phosphate (phosphorus contents around 2.6Â wt.%) and the fire behaviour of their carbon fibre composites is presented. Decomposition pathways are proposed based on the thermal analysis (TG), TG coupled with evolved gas analysis (TG-FTIR), kinetics and analysis of the residue with FTIR and XPS. All organophosphorus-modified hardeners containing phenoxy groups lead to a reduced decomposition temperature and mass loss step for the main decomposition of the cured epoxy resin. With increasing oxidation state of the phosphorus the thermally stable residue increases, whereas the release of phosphorus-containing volatiles decreases. The flammability of the composites was investigated with LOI and UL 94 and the fire behaviour for forced-flaming conditions with cone calorimeter tests performed using different irradiations. The flame retardancy mechanisms are discussed. With increasing oxidation state of the phosphorus additional charring is observed, whereas the flame inhibition, which plays the more important role for the performance of the composites, decreases. The processing and the mechanical performance (delamination resistance, flexural properties and interlaminar bonding strength) of the fibre-reinforced composites containing phosphorus were maintained at a high level and, in some cases, even improved. The potential for optimising flame retardancy while maintaining mechanical properties is highlighted in this study.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Ulrike Braun, Aliaksandr I. Balabanovich, Bernhard Schartel, Uta Knoll, Johannes Artner, Michael Ciesielski, Manfred Döring, Raul Perez, Jan K.W. Sandler, Volker Altstädt, Thorsten Hoffmann, Doris Pospiech,