Synthesis of tetrahydrofuran polymers using calcined silica-alumina or beaching earth catalysts
AssigneeArco Chemical Technology, L.P.
InventorsAndrew P. Kahn, Robert G. Gastinger, Gangfeng Cai
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Abstract
Tetrahydrofuran is polymerized in the presence of a carboxylic acid anhydride and a solid acid catalyst that has been calcined at a temperature greater than about 600.degree. C. Calcined bleaching earth catalysts give THF polymer products having a narrow molecular weight distribution; calcining amorphous silica-aluminas improves their activity toward THF polymerization.
Claims20
A process for producing a tetrahydrofuran polymer, said process comprising polymerizing tetrahydrofuran in the presence of a carboxylic acid anhydride and an effective amount of a solid acid catalyst selected from the group consisting of amorphous silica-aluminas and acid-washed bleaching earths, wherein the catalyst is calcined at a temperature greater than about 600.degree. C. prior to use in the process.
A process for producing a tetrahydrofuran polymer, said process comprising polymerizing tetrahydrofuran in the presence of a carboxylic acid anhydride and an effective amount of amorphous silica-alumina, wherein the silica-alumina is calcined at a temperature greater than about 600.degree. C. prior to use in the process, and wherein the activity of the silica-alumina toward tetrahydrofuran polymerization improves as a result of calcination.
A process for producing a tetrahydrofuran polymer, said process comprising polymerizing tetrahydrofuran in the presence of a carboxylic acid anhydride and an effective amount of an acid-washed bleaching earth, wherein the bleaching earth is calcined at a temperature greater than about 600.degree. C. prior to use in the process, and wherein the molecular weight distribution of the tetrahydrofuran polymer is narrowed as a result of calcination.
A method of preparing an improved tetrahydrofuran polymerization catalyst, said method comprising calcining a solid acid catalyst selected from the group consisting of acid-washed bleaching earths and amorphous silica-aluminas at a temperature greater than about 600.degree. C.
Dependencies are inferred from the claim text.