Polymerization catalysts and polymers

摘要

A method comprising contacting a support material with a transition metal compound to produce a mixture; thermally treating the mixture in the presence of oxygen at a temperature in a range of from about 100° C. to about 500° C. for a period of from about 1 hour to about 10 hours, wherein at least a portion of the transition metal sublimes onto the support material to produce a support material comprising a dispersed transition metal; and thermally treating the support material comprising the dispersed transition metal in an oxidizing atmosphere at a temperature in a range of from about 550° C. to about 900° C. for a period of from about 1 hour to about 10 hours to produce a polymerization catalyst.

主权项

1. A method comprising:
subjecting a support material to a first thermal treatment at a temperature in a range of from about 550° C. to about 900° C. for a period of from about 1 hour to about 10 hours to produce a thermally-treated support material; cooling the thermally-treated support material to a temperature in the range of from about 100° C. to about 150° C.; contacting the thermally-treated support material with chromium (III) acetylacetonate, which is in powder or crystal form, to produce a mixture; and subjecting the mixture in the presence of oxygen to a second thermal treatment at a temperature in a range of from about 100° C. to about 500° C. for a period of from about 1 hour to about 10 hours, wherein at least a portion of the chromium(III) acetylacetonate sublimes onto the support material to produce a polymerization catalyst and wherein the second thermal treatment occurs at a temperature that is less than the first thermal treatment.