Polymers, supersoft elastomers and methods for preparing the same

• US 7,019,082 B2
• Filed: 08/11/2003
• Issued: 03/28/2006
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Carnegie Mellon University
• Original Assignee: Carnegie Mellon University
• Inventors: Matyjaszewski, Krzysztof, Pakula, Tadeusz
• Primary Examiner(s): Lipman, Bernard
• Application Number:
  US10/638,584
• Publication Number:
  US 20040110893A1
• Time in Patent Office: 960 Days
• Field of Search: 526/135, 526/145, 525/301, 525/268, 525/319, 525/322, 525/324
• US Class Current: 525/268
• CPC Class Codes: C08F 265/04 on to polymers of esters
• CPC Class Codes: C08F 283/00 Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
• CPC Class Codes: C08F 290/06 Polymers provided for in subclass C08G
• CPC Class Codes: C08F 291/00 Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds according to more than one of the groups C08F251/00 - C08F289/00
• CPC Class Codes: C08F 293/005 using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent

Abstract

Embodiments of the present invention include a material comprising a polymer having a modulus of elasticity less than 10⁵ Pa and a material comprising a polymer having a modulus of elasticity of less than 5×10⁴ Pa. Embodiments also include a material comprising a polymeric network and a multiplicity of side chains attached to the polymeric network. The multiplicity of side chains may have an average molecular weight below the critical molecular weight for entanglements. In certain embodiments it may be advantageous for the side branches to have a glass transition temperature below the use temperature of the material. The polymer network may comprise at least two monomers so that the polymer network is a copolymer. Embodiments of the present invention also include methods of forming a polymer network. Such as, for example, a method of preparing a polymer network comprising cross-linking a polymer, wherein the polymer comprises a multiplicity of side chains. The polymer may be at least one of a polymer brush, a polymer comb, and a nanocomposite material. An additional embodiment may include polymerizing macromonomers in the presence of a crosslinking agent. This embodiment may result in the forming a polymer network, wherein the polymer network comprises a multiplicity of branches attached to the polymer network, wherein the macromonomers may have a molecular weight less than the critical molecular weight for entanglements. Another embodiment of the method of forming a polymer network may comprising polymerizing monomers directly from a crosslinked polymer network. This method may result in forming a branched polymer network, wherein the polymer network comprises a multiplicity of branches attached to the polymer network.

Claims

1. An elastomeric material, comprising:

a polymer network having a multiplicity of side chains and a rubbery plateau in a modulus of elasticity of less than 10⁵ Pa.

2. The elastomeric material of claim 1, wherein the polymer has a rubbery plateau in a modulus of elasticity of less than 5×

10⁴ Pa.

3. The elastomeric material of claim 2, wherein the polymer has a rubbery plateau in the modulus of elasticity of less than 10⁴ Pa.

4. The elastomeric material of claim 1, wherein at least a portion of the side chains have a glass transition temperature less than 6°

C.

5. The elastomeric material of claim 1, wherein at least a portion of the side chains have a glass transition temperature less than −

20°

C.

6. The elastomeric material of claim 1, wherein a backbone of the polymer network is cross-linked.

7. The elastomeric material of claim 1, wherein a substantial portion of the side chains have a molecular weight below the critical molecular weight for entanglement.

8. The elastomeric material of claim 1, wherein the % elongation of the material is greater than 10%.

9. The elastomeric material of claim 6, wherein the polymer network comprises chemical cross-links.

10. The elastomeric material of claim 6, wherein the polymer network comprises physical cross-links.

11. The elastomeric material of claim 3, wherein the polymer network is lightly cross-linked.

12. The elastomeric material of claim 3, wherein the polymer network is highly cross-linked.

13. The elastomeric material of claim 1, wherein the side chains swell the polymer network.

14. The elastomeric material of claim 13, wherein the side chains comprise greater than 50% of the monomer units in the polymer network.

15. The elastomeric material of claim 14, wherein the side chains comprise greater than 75% of the monomer units in the polymer network.

16. The elastomeric material of claim 15, wherein the side chains comprise greater than 95% of the monomer units in the polymer network.

24. The elastomeric material of claim 1, wherein the polymer network has a modulus of elasticity between 10² Pa and 10⁵ Pa.

25. The elastomeric material of claim 1, wherein the polymer network has a modulus of elasticity between 10² Pa and 10⁴ Pa.

17. A material comprising:

a polymeric network, and

a multiplicity of side chains attached to the polymeric network, wherein the multiplicity of side chains have an average molecular weight below the critical molecular weight for entanglements and are sufficient to swell the polymer network.

18. The material of claim 17, further comprising a multiplicity of branches attached to the side chains.

19. The material of claim 17, wherein at least a portion of the side chains comprise a glass transition temperature less than 0°

C.

20. The material of claims 17, wherein at least a portion of the side chains comprise a glass transition temperature less than −

20°

C.

21. The material of claim 17, wherein the polymer network comprises inorganic components.

22. The material of claim 17, wherein at least one of the polymer network backbone and side chains comprises a copolymer.

23. The material of claim 18, wherein the branches comprise a copolymer.