Abstract: Insulating foam composition for insulation on communication cables, contains 20-95 wt % of an unmodified propylene polymer, having a melt index of 0.1 to 10 g/10 min at 230° C./2.16 kg; and 5-80 wt % of a modified propylene polymer, with a propylene content of up to 100 wt %, and a melt index of 0.05 to 10 g/10 min at 230° C./2.16 kg. The unmodified propylene polymer is a propylene homopolymer; a propylene copolymer of propylene and ethylene or an ?-olefin; a polyolefin mixture containing a crystalline copolymer of propylene and ethylene or an ?-olefin, and an elastic copolymer containing ethylene and propylene or an ?-olefin; or an amorphous, non-isotactic propylene polymer such as a propylene homopolymer, a propylene copolymer containing propylene and an ?-olefin. The modified propylene polymer is a polypropylene modified by reaction with a bismaleimido compound, ionizing radiation, or a peroxide.

Abstract: Insulating foam composition for insulation on communication cables, contains 20-95 wt % of an unmodified propylene polymer, having a melt index of 0.1 to 10 g/10 min at 230° C./2.16 kg; and 5-80 wt % of a modified propylene polymer, with a propylene content of up to 100 wt %, and a melt index of 0.05 to 10 g/10 min at 230° C./2.16 kg. The unmodified propylene polymer is a propylene homopolymer; a propylene copolymer of propylene and ethylene or an &agr;-olefin; a polyolefin mixture containing a crystalline copolymer of propylene and ethylene or an &agr;-olefin, and an elastic copolymer containing ethylene and propylene or an &agr;-olefin; or an amorphous, non-isotactic propylene polymer such as a propylene homopolymer, a propylene copolymer containing propylene and an &agr;-olefin. The modified propylene polymer is a polypropylene modified by reaction with a bismaleimido compound, ionizing radiation, or a peroxide.