Influence of Magnesium Hydroxide and Huntite Hydromagnesite on Mechanical Properties of Ethylene Vinyl Acetate Compounds Cross-linked by DiCumyl Peroxide and Ionizing Radiation

Abstract

Flame retardants including magnesium hydroxide (MH) and huntite hydromagnesite (HH) were used to develop halogen free flame retardant (HFFR) compounds based on ethylene vinyl acetate (EVA) for wire and cable applications. Cone calorimeter and limiting oxygen index (LOI) results show that cross-linking affects not only mechanical properties, but also flame retardancy. Consequently, flame retardancy is mainly influenced by type of flame retardants and mixing ratio of base polymers and to a lesser extent by cross-linking. Tensile strength increased with increase of MH, while elongation at break decreased with increase of MH in cross-linked formulations. On the other hand, elongation at break increased with increase of HH while tensile strength decreased with increase of HH in cross-linked formulations. HFFR compounds with tensile strength of 12 MPa, elongation at break of 200%, LOI of 40% was developed to meet the stringent specifications of wire and cable industry.