Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 μm, and less than 10 wt. % has a particle size less than 10 μm, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm.sup.3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft.sup.2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 μm per five grams of the ethylene polymer.

Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 μm, and less than 10 wt. % has a particle size less than 10 μm, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm.sup.3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft.sup.2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 μm per five grams of the ethylene polymer.

A method comprising a) drying a support material comprising silica at temperature in the range of from about 150° C. to about 220° C. to form a dried support; b) contacting the dried support with methanol to form a slurried support; c) subsequent to b), cooling the slurried support to a temperature of less than about 60° C. to form a cooled slurried support; d) subsequent to c), contacting the cooled slurried support with a titanium alkoxide to form a titanated support; and e) thermally treating the titanated support by heating to a temperature of equal to or greater than about 150° C. for a time period of from about 5 hours to about 30 hours to remove the methanol and yield a dried titanated support.

A method comprising a) drying a support material comprising silica at temperature in the range of from about 150° C. to about 220° C. to form a dried support; b) contacting the dried support with methanol to form a slurried support; c) subsequent to b), cooling the slurried support to a temperature of less than about 60° C. to form a cooled slurried support; d) subsequent to c), contacting the cooled slurried support with a titanium alkoxide to form a titanated support; and e) thermally treating the titanated support by heating to a temperature of equal to or greater than about 150° C. for a time period of from about 5 hours to about 30 hours to remove the methanol and yield a dried titanated support.

A method of preparing a catalyst comprising a) contacting a non-aqueous solvent, a carboxylic acid, and a chromium-containing compound to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst. A method of preparing a catalyst comprising a) contacting a non-aqueous solvent and a carboxylic acid to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed chrominated silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst.

A method of preparing a catalyst comprising a) contacting a non-aqueous solvent, a carboxylic acid, and a chromium-containing compound to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst. A method of preparing a catalyst comprising a) contacting a non-aqueous solvent and a carboxylic acid to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed chrominated silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst.

Various methods of reshaping and recycling thermoset polymers and composites containing thermoset polymers are provided. The methods involve the bond exchange reaction of exchangeable covalent bonds in the polymer matrix with a suitable small molecule solvent in the presence of a catalyst. In some aspects, the methods are applied to a carbon fiber reinforced polymer or a thermoset polymer where the thermoset polymer matrix includes a plurality of ester bonds. Using a small molecule alcohol, the methods provide for recycling one or both of the carbon fiber and the polymer, for welding two surfaces, or for repairing a damaged surface in the materials.

Various methods of reshaping and recycling thermoset polymers and composites containing thermoset polymers are provided. The methods involve the bond exchange reaction of exchangeable covalent bonds in the polymer matrix with a suitable small molecule solvent in the presence of a catalyst. In some aspects, the methods are applied to a carbon fiber reinforced polymer or a thermoset polymer where the thermoset polymer matrix includes a plurality of ester bonds. Using a small molecule alcohol, the methods provide for recycling one or both of the carbon fiber and the polymer, for welding two surfaces, or for repairing a damaged surface in the materials.

A method comprising a) drying a support material comprising silica at temperature in the range of from about 150° C. to about 220° C. to form a dried support; b) contacting the dried support with methanol to form a slurried support; c) subsequent to b), cooling the slurried support to a temperature of less than about 60° C. to form a cooled slurried support; d) subsequent to c), contacting the cooled slurried support with a titanium alkoxide to form a titanated support; and e) thermally treating the titanated support by heating to a temperature of equal to or greater than about 150° C. for a time period of from about 5 hours to about 30 hours to remove the methanol and yield a dried titanated support.

A method comprising a) drying a support material comprising silica at temperature in the range of from about 150° C. to about 220° C. to form a dried support; b) contacting the dried support with methanol to form a slurried support; c) subsequent to b), cooling the slurried support to a temperature of less than about 60° C. to form a cooled slurried support; d) subsequent to c), contacting the cooled slurried support with a titanium alkoxide to form a titanated support; and e) thermally treating the titanated support by heating to a temperature of equal to or greater than about 150° C. for a time period of from about 5 hours to about 30 hours to remove the methanol and yield a dried titanated support.