Composition and method of making two-way shape memory polymer based sealant

Patent metadata

Field	Value
Publication number	US-10934381-B2
Application number	US-201916278915-A
Country	US
Kind code	B2
Filing date	Feb 19, 2019
Priority date	Feb 20, 2018
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

A sealant composition and method for its manufacture are disclosed. A two-way shape memory polymer (2W-SMP) sealant expands upon cooling and contracts upon heating, and thus provides improved sealing for pavements and other structures. The base resin for the sealant is polybutadiene with a high cis content. Uses for the sealant include, but are not limited to: sealant for expansion joint, contraction joint, or construction joint in cement concrete pavement; sealant or sealer for transverse cracks or block cracks in cement concrete pavement or asphalt concrete pavement; sealant for pipelines, lightweight composite structures, roofs, buildings, bridge decks, dams, offshore platforms; sealant for other structures and devices that have previously typically used polymer sealants.

First claim

What is claimed:

1. A composite:
(a) wherein said composite comprises a admixture of polybutadiene, a curing agent, and asphalt; wherein between 20% and 90% of said composite by mass is said polybutadiene; wherein more than 90% of said polybutadiene by mass is cis-polybutadiene; wherein said curing agent, when activated or if activated, crosslinks or will crosslink said butadiene; and wherein between 10% and 80% of said composite by mass is said asphalt; and
(b) wherein said composite, if cured: possesses the capacity to exhibit a two-way shape memory effect: wherein, once said composite has been programmed with tensile stress, thereafter said composite will, if the tensile stress is maintained, expand upon cooling and will contract upon heating over a range of temperatures −30° C. to +50° C.; and wherein this property of expanding upon cooling and contracting upon heating is repeatable over multiple cycles of heating and cooling.

2. The composite of claim 1 , wherein said curing agent comprises 1%-5% dicumyl peroxide; or a mixture of sulfur and N-tert-butyl-benzothiazole sulfonamide.

3. The composite of claim 1 , wherein said composite has been cured, to generate crosslinked polybutadiene molecules.

4. The composite of claim 1 , wherein said composite is uncured, without crosslinked polybutadiene molecules.

5. An article of manufacture comprising the composite of claim 1 and an adhesive surface layer.

6. The article of manufacture of claim 5 , wherein said adhesive comprises an alkyl cyanoacrylate.

7. The article of manufacture of claim 6 , additionally comprising a layer of a silane-modified polymer-based adhesive bonded to said alkyl cyanoacrylate adhesive.

8. An article of manufacture comprising a cement concrete or an asphalt concrete having a joint or crack: wherein said joint or crack is filled with the article of manufacture of claim 7 , wherein said composite has been cured; wherein said silane-modified polymer-based adhesive layer adheres to the concrete to seal the joint or crack; wherein, if following programming said composite with tensile stress, thereafter said composite will expand upon cooling and will contract upon heating over a range of temperatures −30° C. to +50° C., while the concrete will, if tensile stress is maintained, expand upon heating and contract upon cooling over the same range of temperatures; so that overall the joint or crack remains sealed even when the article of manufacture experiences temperature changes within the range −30° C. to +50° C.

9. The article of manufacture of claim 8 , wherein said composite has been programmed with tensile stress, so that said composite will expand upon cooling and will contract upon heating over a range of temperatures −30° C. to +50° C.

10. The article of manufacture of claim 9 , wherein said composite is programmed with the tensile stress before said composite is placed within the joint or crack.

11. The article of manufacture of claim 9 , wherein said composite is programmed with the tensile stress as the result of the inherent contraction of the concrete as the ambient temperature declines.

12. The composite of claim 1 , wherein said composite is self-healing, wherein a crack within said composite can be repaired, and fractured pieces of said composite can be restored to integrity by kneading said composite, thereby eliminating or reducing potential cohesive failure that a crack might otherwise induce.

13. The composite of claim 3 , wherein said composite possesses true two-way shape memory properties, which do not require a persistent external tensile load to maintain the two-way shape memory effect.

14. The composite of claim 3 , wherein said composite possesses advanced two-way shape memory properties, which maintain the two-way shape memory effect under a persistent compressive load upon cooling.

15. A process for making the composite of claim 1 , comprising the steps of dissolving the components of the composite in a common solvent, and then evaporating the solvent to produce said composite.

16. A process for making the composite of claim 1 , comprising the intimate physical mixing of the components in the solid state at ambient temperature, without a liquid-phase solvent, to produce said composite.

17. A process for sealing a joint or crack in a cement concrete or an asphalt concrete having a joint or crack; said process comprising filling the joint or crack with the article of manufacture of claim 7 , wherein said composite has been cured; wherein the silane-modified polymer-based adhesive layer adheres to the concrete to seal the joint or crack; wherein, if following programming the composite with tensile stress, thereafter the composite will expand upon cooling and will contract upon heating over a range of temperatures −30° C. to +50° C., while the concrete will expand upon heating and contract upon cooling over the same range of temperatures; so that overall the joint or crack remains sealed even when the concrete experiences temperature changes within the range −30° C. to +50° C.

18. The process of claim 17 , wherein the composite has been programmed with tensile stress, so that the composite will expand upon cooling and will contract upon heating over a range of temperatures −30° C. to +50° C.

19. The process of claim 18 , wherein the composite is programmed with the tensile stress before the composite is placed within the joint or crack.

20. The process of claim 18 , wherein the composite is programmed with the tensile stress as the result of the inherent contraction of the concrete as the ambient temperature declines.

Assignees

• Lu Lu
• Cao Jinbao
• Li Guoqiang
• Univ Louisiana State

Inventors

• Lu Lu
• Cao Jinbao
• Li Guoqiang

Classifications

• C08L9/00 Primary

  Compositions of homopolymers or copolymers of conjugated diene hydrocarbons · CPC title

• E04B1/68

  of joints, e.g. expansion joints (packing for joints in roads or airfields E01C11/02; expansion joints for bridges E01D19/06; sealing joints between foundation piles E02D5/14; joints in foundation structures E02D29/16; devices for sealing the spaces or joints between roof-covering elements E04D1/36; sealing joints between roof-covering elements E04D3/38; {construction of joints for flooring or floor layers composed of a number of similar elements E04F15/02005}; construction of joints for flooring or floor layers made of masses in situ E04F15/14) · CPC title

• C09J133/14

  of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen · CPC title

• C08K5/0025

  Crosslinking or vulcanising agents; including accelerators · CPC title

• C08F236/06 Primary

  Butadiene · CPC title