Compositions comprising thermoplastic vulcanizate, foamed material and articles made therefrom
The present disclosure relates to a composition comprising a thermoplastic vulcanizate, a propylene-based elastomer and a foaming agent, and to a foamed material comprising said composition. The foamed material has increased tensile properties and tension set while attaining comparable effects of reduction of weight.
1. A composition comprising:
(a) a thermoplastic vulcanizate comprising:
(i) about 5 wt. % to about 85 wt. % of a thermoplastic resin component, and
(ii) about 15 wt. % to about 95 wt. % of a dispersed and at least partially vulcanized rubber component,
based on the total weight of the thermoplastic resin component and the rubber component;
(b) a propylene-based elastomer having at least about 60 wt. % propylene-derived units and about 5 to about 25 wt. % ethylene-derived units, based on total weight of the propylene-based elastomer, and a heat of fusion of less than about 80 J/g; and
(c) a foaming agent.
2. The composition of claim 1 , wherein the rubber component comprises at least one of ethylene-propylene rubber, ethylene-propylene-diene rubber, natural rubber, butyl rubber, halogenated rubber copolymer of p-alkystyrene and at least one isomonoolefin having 4 to 7 carbon atoms, a copolymer of isobutylene and divinyl-benzene, a rubber homopolymer of a conjugated diene having from 4 to 8 carbon atoms, a rubber copolymer having at least 50 weight percent repeat units from at least one conjugated diene having from 4 to 8 carbon atoms and a vinyl aromatic monomer having from 8 to 12 carbon atoms, or acrylonitrile monomer, or an alkyl substituted acrylonitrile monomer having from 3 to 8 carbon atoms, or an unsaturated carboxylic acid monomer, or an unsaturated anhydride of a dicarboxylic acid.
3. The composition of claim 1 , wherein the thermoplastic resin component comprises i) a polymer prepared from olefin monomers having 2 to 7 carbon atoms, or ii) a copolymer prepared from olefin monomers having 2 to 7 carbon atoms with a (meth)acrylate or a vinyl acetate.
4. The composition of claim 1 , wherein the thermoplastic resin component comprises at least one of polyethylene, polypropylene, and ethylene-propylene copolymer.
5. The composition of claim 1 , wherein the propylene-based elastomer is added in an amount of from about 1% to about 30% based on the total weight of the thermoplastic vulcanizate and the propylene-based elastomer.
6. The composition of claim 1 , wherein the propylene-based elastomer is added in an amount of from about 3% to about 15% based on the total weight of the thermoplastic vulcanizate and the propylene-based elastomer.
7. The composition of claim 1 , wherein the foaming agent is added in an amount of from about 0.1 to about 10.0% relative to the total weight of the thermoplastic vulcanizate and the propylene-based elastomer.
8. The composition claim 1 , wherein the foaming agent is added in an amount of from about 0.3 to about 3.0% relative to the total weight of the thermoplastic vulcanizate and the propylene-based elastomer.
9. The composition of claim 1 , wherein the foaming agent comprises at least one of 4,4′-oxybis benzene sulfonyl hydrazide, azodicarbonamide, azobisformamide, azobisisobutyronitrile, diazoaminobenzene, N,N-dimethyl-N,N-dinitroso terephthalamide, N,N-dinitrosopentamethylene-tetramine, benzenesulfonyl-hydrazide, benzene-1,3-disulfonyl hydrazide; diphenylsulfon-3-3, disulfonyl hydrazide, p-toluene sulfonyl semicarbizide, barium azodicarboxylate, butylamine nitrile, nitroureas, trihydrazino triazine, phenyl-methyl-uranthan, p-sulfonhydrazide, and peroxides.
10. The composition of claim 1 , wherein the foaming agent comprises azodicarbonamide.
11. The composition of claim 1 further comprising at least one of a filler, processing aid, curing agent, and accelerator.
12. A method for making a composition, comprising the steps of:
(1) combining
(a) a thermoplastic vulcanizate comprising:
(i) about 5 wt. % to about 85 wt. % of a thermoplastic resin component, and
(ii) about 15 wt. % to about 95 wt. % of a dispersed and at least partially vulcanized rubber component, based on the total weight of the thermoplastic resin component and the rubber component;
(b) a propylene-based elastomer having at least about 60 wt. % propylene-derived units and about 5 to about 25 wt. % ethylene-derived units, based on total weight of the propylene-based elastomer, and a heat of fusion of less than about 80 J/g; and
(c) a foaming agent; and
(2) forming the composition.
13. A foamed material made from the composition of claim 1 .
14. The foamed material of claim 13 having a tensile strength at break, as measured according to ISO-37, at least about 5% greater than the tensile strength at break of a comparative material sample that is a foamed material made from a composition free of the propylene-based elastomer, but is otherwise identical in terms of its constituents.
15. The foamed material of claim 13 having a tensile strength at break, as measured according to ISO 37, at least about 10% greater than the tensile strength at break of a comparative material sample that is a foamed material made from a composition free of the propylene-based elastomer, but is otherwise identical in terms of its constituents.
16. The foamed material of claim 13 having a tension set (25% extension at 80° C.), of less than about 20%.
17. The foamed material of claim 13 having an elongation at break, as measured according to ISO 37, of greater than 350%.
18. The method of claim 12 , wherein forming the composition comprises extruding the composition to form a foamed material.
19. The method of claim 18 , wherein the foamed material has a tensile strength at break, as measured according to ISO-37, at least 5% greater than the tensile strength at break of a comparative material sample that is a foamed material made from a composition free of the propylene-based elastomer, but is otherwise identical in terms of its constituents.