Poly(ethylene vinyl acetate) (EVA)/low density polyethylene (LDPE)/ammonium polyphosphate (APP) composites cross-linked by dicumyl peroxide for wire and cable applications

Formulations of chemically cross-linked poly(ethylene vinyl acetate) (EVA) and low density polyethylene (LDPE) blends containing intumescent flame retardant such as ammonium polyphosphate (APP) were prepared. Influence of polyethylene grafted with maleic anhydride (PEgMA), boric acid or combinations of them as well as various EVA/LDPE ratios on flammability, mechanical, thermal and electrical properties was investigated. Flame retardancy was found to be improved after addition of boric acid to APP formulations. On the other hand, mechanical properties decreased for formulations containing boric acid. Combination of boric acid with PEgMA gives formulations with good mechanical and thermal properties as well, as good flame retardancy. Good thermal properties based on retention of mechanical properties after thermal aging were observed for all formulations due to introduction of cross-linking. All formulations show also good electrical properties.