Thermoplastic elastomer compositions rheology-modified using peroxides and free radical coagents
AssigneeDuPont Dow Elastomers L.L.C.
InventorKim L Walton
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Abstract
Rheology-modified thermoplastic elastomer compositions comprising a melt blend of an ethylene/α-olefin polymer and a high melting polymer such as polypropylene or a propylene/α-olefin copolymer wherein the rheology modification is induced by a combination of a peroxide and a free radical coagent. The resulting compositions have an elastomeric phase, a non-elastomeric phase and certain physical properties that exceed those of a like composition that is rheology-modified by peroxide alone. The compositions can be used to make a variety of articles of manufacture, such as automotive instrument panel skins, via calendaring and thermoforming procedures.
Claims13
A rheology-modified, substantially gel-free thermoplastic elastomer composition comprising at least one elastomeric ethylene/alpha-olefin polymer or ethylene/alpha-olefin polymer blend and at least one high melting polymer selected from the group consisting of polypropylene homopolymers and propylene/ethylene copolymers, wherein the rheology modification is induced by a combination comprising a peroxide and a free radical coagent and the composition has a melt toughness of at least about 600 cNmm/s, a true ultimate tensile strength at 140° C. of at least about 3 MPa and an elongation to break at 140° C. of least about 400%.
Dependencies are inferred from the claim text.