Microparticles from thermomechanically degraded PTFE

1. Microparticles comprising poly(tetrafluoroethylene),

wherein the microparticles exhibit a Dv50 of about 20 μm to about 30 μm and an improved specific surface area (SSA) for particles of that size range of at least about 3.0 m 2 /g when measured by a multipoint BET method of ISO 9277; and

wherein the microparticles are prepared via thermomechanically degrading scrap PTFE in the presence of air and/or oxygen and reducing particle size of the degraded PTFE.

2. The microparticles of claim 1 , wherein the microparticles consist essentially of the poly(tetrafluoroethylene) and modified poly(tetrafluoroethylene) species.

3. The microparticles of claim 2 , wherein the modified poly(tetrafluoroethylene) species comprise poly(tetrafluoroethylene) modified by one or more of oxygen atoms, additional carbon atoms, and/or additional hydrogen atoms.

4. The microparticles of claim 1 , wherein the PTFE microparticles are prepared via a method that does not comprise irradiation.

5. The microparticles of claim 1 , wherein the thermomechanical degrading comprises passing the PTFE multiple times through equipment designed for thermomechanical degradation.

6. The microparticles of claim 1 , wherein the reducing particle size comprises passing the degraded PTFE multiple times through equipment designed for particle size reduction.

7. The microparticles of claim 1 , wherein the thermomechanical degrading is conducted in an extruder.

8. The microparticles of claim 1 , wherein the thermomechanical degrading is conducted in an internal mixer.

9. The microparticles of claim 1 , wherein the scrap PTFE is in sintered form.

10. The microparticles of claim 1 , wherein the scrap PTFE is in unsintered form.

11. A product selected from the group consisting of lubricants and pigments, comprising the microparticles of claim 1 .

12. A method for providing microparticles comprising PTFE, comprising:

providing scrap PTFE;

degrading the scrap PTFE thermally and mechanically in the presence of air and/or oxygen to give degraded PTFE; and

reducing the particle size of the degraded PTFE by grinding or milling;

wherein the microparticles exhibit a Dv50 of about 20 μm to about 30 μm and an improved specific surface area (SSA) for particles of that size range of at least about 3.0 m 2 /g when measured by a multipoint BET method of ISO 9277,

wherein the method does not comprise irradiation.

13. The method of claim 12 , wherein the microparticles form a line on a plot of SSA versus Dv50 with a slope of at least around −0.05 m 2 /g·μm and a y-intercept of at least around 4.0 m 2 /g.

14. The method of claim 12 , wherein the scrap PTFE is in sintered form.

15. The method of claim 12 , wherein the scrap PTFE is in unsintered form.

16. The method of claim 12 , wherein the degrading is conducted in an extruder or an internal mixer.

17. The method of claim 12 , wherein the degrading is conducted in an environment comprising an oxygen:nitrogen ratio of about 0.4 or greater.

18. The method of claim 12 , further comprising repeating the degrading step two or more times.

19. The method of claim 12 , further comprising repeating the reducing step two or more times.

20. The method of claim 12 , further comprising separating the micropowder obtained after the reducing step into fractions according to particle size.

21. The method of claim 20 , wherein the separating comprises sieving or processing with an air classifier to give the microparticles.

22. Microparticles obtained by the process of claim 12 .