A static sealing member is provided that includes a composition having a silane-crosslinked polyolefin elastomer with a density less than 0.90 g/cm.sup.3. The static sealing member can exhibit a compression set of from about 5.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70? C.). The silane-crosslinked polyolefin elastomer can include a first polyolefin having a density less than 0.86 g/cm.sup.3, a second polyolefin having a crystallinity less than 40%, a silane crosslinker, a grafting initiator, and a condensation catalyst.

A microdense sealing member is provided. The microdense sealing member includes a composition having a foamed silane-crosslinked polyolefin elastomer with a density less than 0.70 g/cm.sup.3. The microdense sealing member can exhibit a compression set of from about 5.0% to about 35.0% measured according to ASTM D 395 (22 hrs @ 70? C.). The foamed silane-crosslinked polyolefin elastomer can be produced from a blend including a first polyolefin having a density less than 0.86 g/cm.sup.3, a second polyolefin having a crystallinity less than 60? C., a silane crosslinker, a grafting initiator, a condensation catalyst, and a microencapsulated foaming agent.

A combined sealing member is provided that includes a composition comprising two or more polyolefin elastomers selected from the group consisting of a dense, a micro-dense and a dynamic silane-crosslinked polyolefin elastomer having a respective density of less than 0.90 g/cm.sup.3, less than 0.70 g/cm.sup.3, and less than 0.60 g/cm.sup.3. The combined sealing member exhibits a compression set of from about 5.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70? C.).

A sponge sealing member is provided that includes a composition having a silane-crosslinked polyolefin elastomer with a density less than 0.60 g/cm.sup.3. The sponge sealing member can exhibit a compression set of from about 5.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70? C.). The silane-crosslinked polyolefin elastomer can also include a first polyolefin having a density less than 0.86 g/cm.sup.3, a second polyolefin having a crystallinity less than 40%, a silane crosslinker, a grafting initiator, a condensation catalyst, and a foaming agent.

A seal member includes silicone rubber mixed with a polyrotaxane. The seal member includes the polyrotaxane in an amount of 3 to 10 parts by mass per 100 parts by mass of the silicone rubber. This configuration can allow molecules in the silicone rubber to slide on one another, so that the rubber material is easily deformed according to stress applied, such as insertion and removal of terminal metal pieces. Accordingly, scratch damage of the seal member can be reduced.

An EPDM composition that includes 1 to 12 parts by weight of liquid polybutadiene and 1 to 12 parts by weight of a plant-derived component-containing terpene resin based on 100 parts by weight of a plant-derived component-containing ethylene-propylene-diene terpolymer. The EPDM composition is obtained by adding, to EPDM that has, at least in part, a plant-derived component with low environmental impact, liquid polybutadiene, which is compatible with EPDM and can improve roll processability by reducing the compound viscosity, and further using a specific amount of a plant-derived component-containing terpene resin for the biomass degree, which is reduced due to the addition of the liquid. The rate of change in biomass degree is less than 1.5% in comparison to a composition to which liquid polybutadiene and a plant-derived component-containing terpene resin are not added.

An acrylic rubber contains (a) methyl methacrylate units, (b) ethyl acrylate units, (c) n-butyl acrylate units, (d) 2-methoxyethyl acrylate units, and (e) cross-linking site monomer units, in which the acrylic rubber contains 10 to 20% by weight of (a) the methyl methacrylate units, 15% by weight or less of (b) the ethyl acrylate units, 60 to 80% by weight of (c) the n-butyl acrylate units, 10 to 30% by weight of (d) the 2-methoxyethyl acrylate units, and 0.5 to 5% by weight of (e) the cross-linking site monomer units.

Methods, compositions, apparatuses, and systems are provided for a hybrid thermoplastic gel or sealant. The methods comprise providing (a) a base polymer having at least one functional group capable of crosslinking, (b) a functionalized extender, and (c) heat, and reacting the base polymer and functionalized extender in the presence of the heat to form the hybrid thermoplastic gel. The gel composition may comprise 5-40 wt % of a base polymer, 60-95 wt % of a functionalized extender, and 0-10 wt % of a crosslinker. A closure or interconnect system may comprise a housing, a cable, and a hybrid thermoplastic gel or sealant. A telecommunications apparatus may comprise a telecommunications component and a sealant that forms a seal with the telecommunications component. The sealant may comprise a sealant material having a first range of elongation followed by a second range of elongation.

A seal member includes silicone rubber mixed with a polyrotaxane. The seal member includes the polyrotaxane in an amount of 3 to 10 parts by mass per 100 parts by mass of the silicone rubber. This configuration can allow molecules in the silicone rubber to slide on one another, so that the rubber material is easily deformed according to stress applied, such as insertion and removal of terminal metal pieces. Accordingly, scratch damage of the seal member can be reduced.

An acrylic rubber contains (a) methyl methacrylate units, (b) ethyl acrylate units, (c) n-butyl acrylate units, (d) 2-methoxyethyl acrylate units, and (e) cross-linking site monomer units, in which the acrylic rubber contains 10 to 20% by weight of (a) the methyl methacrylate units, 15% by weight or less of (b) the ethyl acrylate units, 60 to 80% by weight of (c) the n-butyl acrylate units, 10 to 30% by weight of (d) the 2-methoxyethyl acrylate units, and 0.5 to 5% by weight of (e) the cross-linking site monomer units.