Variable TG article, method of making, and use of same

1. An article comprising:

a crosslinked product of:

a first crosslinked polymer; and

a second crosslinked polymer different from the first crosslinked polymer, the article having a gradient in glass transition temperature;

wherein the first crosslinked polymer is crosslinked with the second crosslinked polymer; and

wherein the first crosslinked polymer and the second crosslinked polymer comprise crosslinked polyphenylene sulfide, crosslinked polyphenylsulfone, crosslinked self-reinforced polyphenylene, crosslinked polyethersulfone, or a combination comprising at least one of the foregoing.

2. The article of claim 1 , wherein the article comprises the crosslinked product of crosslinked polyphenylene sulfide, crosslinked polyphenylsulfone, and crosslinked self-reinforced polyphenylene.

3. The article of claim 1 , further comprising an additive, which includes silica, glass fiber, carbon fiber, or carbon black, or a combination comprising at least one of the foregoing.

4. The article of claim 1 , wherein the article has a gradient in the concentration o f the first crosslinked polymer, second crosslinked polymer, or a combination of at least one of the foregoing.

5. The article of claim 1 , wherein the article has a gradient in the ratio of the amount of the first crosslinked polymer to the amount of the second crosslinked polymer.

6. The article of claim 5 , wherein the ratio of the amount of the first crosslinked polymer to the amount of the second crosslinked polymer is 1:1000 to 1000:1, based on the weight of the first and second crosslinked polymers.

7. The article of claim 1 , wherein the article has a first portion corresponding to a first glass transition temperature, and a second portion corresponding to a second glass transition temperature, the first glass transition temperature being greater than the second glass transition temperature in the gradient, and

wherein the first portion is in a glassy state, and the second portion is in an elastic state in response to exposure of the article to a temperature greater than a minimum value of the glass transition temperature of the article and less than a maximum value of the glass transition temperature of the article.

8. The article of claim 1 , wherein the elastic state is present from 200° F. to 700° F.

9. An article comprising:

a crosslinked product of:

a first crosslinked polymer; and

a second crosslinked polymer,

the article having a gradient in glass transition temperature, wherein the article has a glass transition which occurs over a temperature domain of 300 degrees on the Fahrenheit temperature scale.

10. The article of claim 1 , wherein the article has a glass transition which occurs over a temperature domain which is greater than 100 degrees on the Fahrenheit temperature scale.

11. The article of claim 9 , wherein the gradient in glass transition corresponds to a temperature domain of 200° F. to 500° F.

12. The article of claim 1 , wherein the gradient in glass transition temperature is continuous.

13. The article of claim 1 , wherein the gradient in glass transition temperature is discontinuous.

14. The article of claim 1 , wherein the first crosslinked polymer has a first crosslink density, and the second crosslinked polymer has a second crosslink density.

15. The article of claim 14 , wherein the first crosslink density is different than the second crosslink density.

16. The article of claim 1 , wherein the first crosslinked polymer is different than the second crosslinked polymer.

17. The article of claim 1 , wherein the article has a thermal decomposition temperature greater than 700° F.

18. An article comprising:

a crosslinked product of:

a first crosslinked polymer; and

a second crosslinked polymer different from the first crosslinked polymer,

where the first crosslinked polymer is crosslinked with the cross second crossiinked polymer; and

wherein the first crosslinked polymer and the second crosslinked polymer comprise crosslinked polyphenylene sulfide, crosslinked polyphenylsufone, crosslinked self-reinforced polyphenylene, crosslinked polyethersulfone,or a combination comprising at least one of the foregoing; and

wherein the article has a gradient in glass transition temperature, a gradient in crosslink density, and is configured to have a self backup property at a temperature from a minimum Tg value to less than a maximum Tg value of the gradient in glass transition temperature.

19. A process for making an article, the process comprising:

combining a first crosslinked polymer and a second crosslinked polymer different from the first polymer to form a composition;

compressing the composition;

heating the composition; and

crosslinking the first crosslinked polymer with the second crosslinked polymer to form the article, the article having a gradient in glass transition temperature;

wherein the first crosslinked polymer and the second crosslinked polymer comprise crosslinked polyphenylene sulfide, crosslinked polyphenylsulfone, cosslinked self-reforced polyphenylene, crosslinked polyethersuftone, or a combination comprising at least one of the foregoing.

20. The process of claim 19 , further comprising introducing a crosslinking agent to the first crosslinked polymer, second crosslinked polymer, or a combination thereof.

21. The process of claim 19 , wherein the combining comprises:

introducing the first crosslinked polymer at a first feed rate; and

introducing the second crosslinked polymer at a second feed rate,

wherein the first feed rate, second feed rate, or both first and second feed rate are variable.

22. The process of claim 21 , wherein combining comprises:

decreasing the first feed rate of the first crosslinked polymer; and

increasing the second feed rate of the second crosslinked polymer.

23. The process of claim 21 , further comprising varying the ratio of the amount of the first crosslinked polymer to the amount ofthe second crosslinked polymer during combining the first and second crosslinked polymers.