Study of a halogen-free flame-retarded Polypropylene composition with balanced strength and toughness

A nitrogen?phosphorus (N?P) Intumescent Flame Retardant (IFR) was applied for the halogen-free flame-retarded Polypropylene (PP) composition. The matrix resin, toughening materials and strengthening materials were selected for improving the tensile and impact properties of the flame-retarded PP. Orthogonal experiments were performed to produce an optimum recipe with balanced flame retardancy, impact strength and tensile strength. The Charpy impact strength and the tensile strength of PP/IFR/R1/G2/additive (62.8/28/4/5/0.2) were 28.56 MPa and 7.74 kJ/m², respectively. At the same time, this composition could reach UL V0 level in the vertical combustion test, which is satisfied for the need of usual engineering application.