De-chao Sun, Youwei Yao
Oct 1, 2011
Citations
1
Influential Citations
134
Citations
Quality indicators
Journal
Polymer Degradation and Stability
Abstract
Abstract One symmetric diamine ( 4 ) and two symmetric phenols ( 5 ) and ( 6 ) were synthesized as phosphorus-containing flame retardants. The synthesis comprised a two-step procedure: the condensation of p -phenylenediamine with benzaldehyde, 4-hydroxybenzaldehyde and 2-hydroxybenzaldehyde respectively, followed by the addition of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the imine linkage. The structures of ( 4 )–( 6 ) were characterized by FTIR, NMR and mass spectra. ( 4 )–( 6 ) served as co-curing agents of diaminodiphenylmethane for epoxy resins, and epoxy thermosets exhibited excellent flame retardancy, moderate changes in glass transition temperature ( T g ) and thermal stability. When the phosphorus content reached 1.0 wt.%, the epoxy resin system met the UL-94 V-0 classification and the limiting oxygen index (LOI) reached more than 35.6, probably because of the nitrogen–phosphorus synergistic effect.