Effect of intumescent ammonium polyphosphate (APP) and melamine cyanurate (MC) on the properties of epoxy/glass fiber composites

The effects of halogen-free flame retardants (FR) such as intumescent ammonium polyphosphate (APP) and melamine cyanurate (MC) on the flammability and mechanical properties of epoxy/glass fiber composite systems were studied. Overall, intumescent APP shows better flammability results compared with MC. The composite with 5 vol.% APP performed sufficiently well in the UL-94 test and LOI, whereas 20 vol.% MC is required to achieve similar results. The addition of 1 vol.% MC into 4 vol.% APP had shown some improvement on the composite flame resistance. The composite attains the maximum flexural strength at 15 vol.% while the dynamic mechanical analysis shows that the addition of flame retardants increased the storage modulus but did not change the glass transition temperature T-g. (C) 2011 Elsevier Ltd. All rights reserved.