Fusible oil gel compositions and methods of making and using same
A gel composition is herein disclosed. According to one embodiment, the composition comprises a (i) a styrenic block copolymer, (ii) an oil; and (iii) optional additives; wherein the styrenic block copolymer has a structure ABi or iAB, wherein A is a monoalkenyl arene block, B is a conjugated diene block, and i is an isoprene attachment. The isoprene attachment i is substantially unsaturated and the conjugated diene block B is substantially saturated. The gel composition before curing exhibits thixotropic behavior, with a viscosity ranging from about 5000 mPa·s to about 30000 mPa·s. at 25° C. and a shear rate of 20 s −1 .
1. A gel composition comprising: (i) a styrenic block copolymer, (ii) an oil; and (iii) optional additives:
wherein the styrenic block copolymer has a structure ABi or iAB, where
A is a monoalkenyl arene block,
B is a conjugated diene block,
i is an isoprene attachment,
the isoprene attachment i is substantially unsaturated and B is substantially saturated,
the monoalkenyl arene block has a molecular weight ranging from 35 kg/mol to 100 kg/mol;
wherein
the gel composition before curing is not solid, with a viscosity ranging from about 5000 mPa·s to about 30000 mPa·s. at 25° C. and a shear rate of 20 s −1 ; and
the gel composition after curing is solid.
2. The gel composition of claim 1 , wherein the styrenic block copolymer has a structure of ABi or iAB, and wherein the isoprene attachment i has a hydrogenation level of <50% and the conjugated diene B block has a hydrogenation level of >90%.
3. The gel composition of claim 2 , wherein the isoprene attachment i has a hydrogenation level of <40% and the conjugated diene B block has a hydrogenation level of >95%.
4. The gel composition of claim 3 , wherein the isoprene attachment i has a hydrogenation level of <35% and the conjugated diene B block has a hydrogenation level of >98%.
5. The gel composition of claim 1 , wherein at least 75% of double bonds present in the conjugated diene B block are hydrogenated.
6. The gel composition of claim 1 , wherein from about 20% to about 60% of the double bonds in the isoprene attachment i are hydrogenated.
7. The gel composition of claim 1 , wherein a difference in the hydrogenation level of the conjugated diene B block and the hydrogenation level of the isoprene attachment i is greater than about 20%.
8. The gel composition of claim 1 , wherein the styrenic block copolymer has a total residual unsaturation of from about 0.2 milliequivalents/gram to about 4 milliequivalents/gram.
9. The gel composition of claim 1 , wherein the monoalkenyl arene A block comprises styrene, alpha-methylstyrene, para-methylstyrene, vinyl toluene, vinylnaphthalene, diphenyl ethylene, para-butyl styrene, or mixtures thereof.
10. The gel composition of claim 1 , wherein the monoalkenyl arene A block has a polystyrene content of from about 15% to about 40%.
11. The gel composition of claim 1 , wherein the monoalkenyl arene A block has an apparent molecular weight of at least 40 kg/mol.
12. The gel composition of claim 1 , wherein the conjugated diene B block comprises conjugated 1,3-butadiene or conjugated substituted butadienes.
13. The gel composition of claim 1 , wherein the conjugated diene block B has an apparent molecular weight of from about 30 kg/mol to about 150 kg/mol.
14. The gel composition of claim 1 , wherein the isoprene attachment i has an apparent molecular weight of from about 2 kg/mol to about 15 kg/mol.
15. The gel composition of claim 1 , wherein the styrenic block copolymer further comprises less than 5 wt. % of a styrenic triblock copolymer based on the total weight of the styrenic block copolymer.
16. The gel composition of claim 1 , wherein the styrenic block copolymer is present in an amount of from about 1 wt. % to about 30 wt. % based on the total weight of the composition.
17. The gel composition of claim 1 , wherein the oil is present in an amount of from about 70 wt. % to about 99 wt. % based on the total weight of the composition, and wherein the oil comprises a paraffin, a mineral oil, a gas-to-liquid oil, a synthetic oil, or combinations thereof.
18. The gel composition of claim 1 , wherein the optional additives comprise an antioxidant, a metal deactivator, a curing accelerator, a rheology modifier, or combinations thereof.
19. The gel composition of claim 1 , wherein the gel composition is cured by any of UV irradiation, thermal treatment, or both, to form a solid gel after curing.
20. The gel composition of claim 12 , wherein the conjugated substituted butadiene is piperylene, 2,3-dimethyl-1,3-butadiene, 1-phenyl-1,3-butadiene or mixtures thereof.