초록 |
To investigate flame retarding abilities according to the chemical structure, two reactive-type phosphorus/nitrogen flame retardants (PNFR) are synthesized and characterized via 1H NMR. They have the flexible and rigid chemical structure, respectively. The flame retarding mechanism of each flame retardant was confirmed via FTIR by temperature. The cross-linked epoxy polymers are prepared by curing bisphenol A diglycidyl ether (BADGE) and 4,4’-diaminodiphenylmethane (DDM) with/without PNFR. To evaluate the flame retardancy of PNFRs, limiting oxygen index (LOI) and vertical burning test (UL 94) are performed. After the flame retardancy test, the morphology of char residues is recorded using SEM. TGA and DSC are conducted to investigate the thermal stabilities and melting behaviors, respectively. The results shown that flame retarding ability and thermal stability of rigid PNFR are relatively higher than that of flexible PNFR. |