Poly(tetrafluoroethylene) zeolite composite and methods
View Patent ↗The present application thus provides a composite composition comprising PTFE and zeolite. According to another aspect, the present application provides a method for making a composite article comprising bonding zeolite to PTFE. According to still yet another aspect of the present application, a method for separating components of the mixture comprising contacting the mixture with a composite composition comprising PTFE and zeolite is disclosed.
1. A method for making a composite article consisting essentially of:
mixing a zeolite, a poly(tetrafluoroethylene), and a lubricant to form a mixture;
pressing the mixture to form a preform;
extruding the preform into a tape or sheet;
stretching the tape or sheet biaxially; and
stabilizing the biaxially stretched tape or sheet by applying heat, wherein the stabilizing step occurs at a temperature of about 650° F. to about 750° F.
2. The method of claim 1 , wherein the poly(tetrafluoroethylene) is a powder.
3. The method of claim 1 , wherein the preform is cylindrical.
4. The method of claim 1 , wherein the preform is formed by pressure.
5. The method of claim 4 , wherein the pressure is about 150 psi.
6. The method of claim 1 , wherein the extrusion is performed at a temperature of about 80° C.
7. The method of claim 1 , wherein the biaxial stretching of the tape or sheet occurs at a temperature ranging from about 300° F. to about 800° F.
8. The method of claim 1 , wherein the lubricant is an isoparaffinic solvent.
9. The method of claim 1 , wherein the calendar rolls are about 300° F.
10. The method of claim 1 , wherein the tape or sheet is about 4 to about 20 mils thick prior to biaxially stretching the tape or sheet.
11. A method for making a composite article consisting essentially of:
mixing a zeolite, a poly(tetrafluoroethylene), and a lubricant a mixture;
pressing the mixture to form a preform;
extruding the preform into a tape or sheet;
passing the tape or sheet through calendar rolls to evaporate the lubricant;
stretching the tape or sheet biaxially; and
stabilizing the biaxially stretched tape or sheet by a applying heat, wherein the stabilizing step occurs at a temperature of about 650° F. to about 750° F.