Elastomeric propylene-ethylene-diene terpolymer compositions
In some embodiments, the present disclosure provides a composition comprising from 5 phr to 30 phr of a PEDM terpolymer having 1 to 10 wt % diene, 13 to 40 wt % ethylene, and 15 to 85 wt % propylene, based on the weight of the PEDM terpolymer. The composition further comprises from 70 phr to 95 phr of an ethylene-based copolymer comprising an ethylene content different than the first polymer, a C 3 to C 12 α-olefin, and, optionally, one or more dienes.
1. A composition comprising:
from 5 to 30 parts by weight per hundred parts by weight rubber (phr) of a propylene-α-olefin-diene (PEDM) terpolymer comprising 1 to 10 wt % diene, 13 to 40 wt % α-olefin, and 15 to 85 wt % propylene, said wt % based on the weight of the PEDM terpolymer; and
from 70 to 95 phr of an ethylene-based copolymer comprising ethylene, one or more C 3 to C 12 α-olefins, and, optionally, one or more dienes; wherein the amount of ethylene content of the ethylene-based copolymer (in wt % on the basis of total weight of the ethylene-based copolymer) is different from the amount of α-olefin content of the PEDM terpolymer (in wt % on the basis of total weight of the PEDM terpolymer).
2. The composition of claim 1 , wherein the PEDM is formed by polymerizing propylene, one or more α-olefins, and one or more dienes in the presence of a bridged fluorenyl-cyclopentadienyl group 4 catalyst that has been activated by an activator;
wherein the catalyst is represented by Formula (I):
wherein J is a divalent bridging group;
M is a group 4 transition metal;
each X is independently a univalent anionic ligand, or two Xs are joined together to form a metallocycle ring with M, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand;
each R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , and R 10 is independently hydrogen, C 1 to C 50 substituted or unsubstituted alkyl, provided that any one or more of the pairs R 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 6 and R 7 , R 8 and R 9 , and R 9 and R 10 , may optionally be bonded together to form a saturated or partially saturated cyclic or fused ring structure; and
the activator is a non-coordinating anion activator.
3. The composition of claim 2 , wherein the bridged fluorenyl-cyclopentadienyl group 4 catalyst is 1,1′-bis(4-triethylsilylphenyl)methylene(cyclopentadienyl)(2,7-di-tertiary-butyl-fluoren-9-yl)hafnium dimethyl.
4. The composition of claim 2 , wherein the activator is N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate.
5. The composition of claim 1 , wherein the PEDM terpolymer has a H f less than 1 J/g.
6. The composition of claim 1 , wherein the PEDM terpolymer has a crystallinity of from 0.1% to 5%, as determined by differential scanning calorimetry.
7. The composition of claim 1 , wherein the PEDM terpolymer has atactic propylene sequences.
8. The composition of claim 1 , wherein the PEDM terpolymer has an α-olefin that is ethylene and an ethylene content from 30 wt % to 40 wt %.
9. The composition of claim 1 , wherein the diene of the PEDM terpolymer is one or more of 5-ethylidene-2-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, 1,4-hexadiene, alkyldicyclopentadiene, 1,4-pentadiene, 1,5-hexadiene, 1,4-heptadiene, 2-methyl-1,5-hexadiene, cyclooctadiene, 1,4-octadiene, 1,7-octadiene, 5-n-propylidene-2-norbornene, 5-(2-methyl-2-butenyl)-2-norborene, and norbornadiene.
10. The composition of claim 9 , wherein the diene of the PEDM terpolymer is 5-ethylidene-2-norbornene.
11. The composition of claim 1 , wherein the PEDM terpolymer has a diene content from 2 wt % to 4 wt %.
12. The composition of claim 1 , wherein the ethylene-based copolymer comprises 40 to 95 wt % ethylene, 0 to 10 wt % of one or more dienes, and a C 3 to C 12 α-olefin, said wt % s based on the total weight of the ethylene-based copolymer.
13. The composition of claim 1 , wherein the C 3 to C 12 α-olefin of the ethylene-based copolymer is propylene or 1-butene.
14. The composition of claim 1 , wherein the C 3 to C 12 α-olefin of the ethylene-based copolymer is propylene.
15. An at least partially cross-linked elastomeric composition that is the reaction product of:
a composition according to claim 1 ;
one or more vulcanization activators; and
one or more vulcanizing agents.
16. The composition of claim 15 , further comprising one or more additives comprising at least one of carbon black and/or process oil.
17. The composition of claim 16 , wherein the composition comprises from 1 phr to 150 phr of a paraffinic process oil, the paraffinic process oil having a viscosity at 40° C. within the range from 80 to 600 CSt.
18. The composition of claim 16 , further comprising a mineral filler.
19. The composition of claim 15 , wherein the composition has a tack of about 4,000 Pa or greater and a green strength 25% modulus of about 1.7 MPa or greater.
20. The composition of claim 15 , wherein the composition has a tensile strength at break of 21.4 MPa or greater.
21. The composition of claim 15 , wherein the composition has a tack of at least about 3.4 kPa.
22. The composition of claim 21 , wherein the composition has a tack of at least about 5.5 kPa.
23. A transmission belt, comprising:
a composition according to claim 1 .
24. The transmission belt of claim 23 , further comprising at least one of a filler, a plasticizer, or a stabilizer.