Intumescent flame retardation of EVA using microencapsulated ammonium polyphosphate and pentaerythritols

With a melamine-formaldehyde (MF) resin coating layer, microencapsulated ammonium polyphosphate (MCAPP) is prepared by in situ polymerization and is characterized by XPS and water leaching test. The microencapsulation of APP with the MF resin leads to a decrease in the particle's water leaching rate. The flame-retardant action of MCAPP and APP in EVA are studied using LOI and UL 94 test, and their thermal stability is evaluated by thermogravimetric analysis (TGA). The LOI value of the EVA/MCAPP composite at the same loading is higher than the value of the EVA/APP composite. In comparison with the EVA/MCAPP composites, it is found that the LOI values of the EVA/MCAPP/PER and EVA/MCAPP/DPER ternary composites at the same additive loading increase, and UL 94 ratings of most ternary composites are raised to V-0. The water-resistant properties of the EVA composites are studied, and the results of the composites containing with APP and MCAPP are compared. Moreover, the peroxide cross-linking of the EVA composites is investigated, and the mechanical properties and thermal stability of the composites increase after the cross-linking.