Method for producing tetrahydrofuran polymers
US6559278B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Mar 30, 2001 |
| Grant date | May 6, 2003 |
| Priority date | — |
| Expiry date | Mar 30, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G65/2657
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention relates to a method for continuously or discontinuously producing tetrahydrofuran polymers by homopolymerization of tetrahydrofuran, alkyl-substituted tetrahydrofurans and/or alkylene oxides in the presence of carboxylic acid anhydrides or compounds containing reactive hydrogen using an optionally non-acidified or acid-activated calcined and granular natural amorphous aluminum silicate catalyst. The inventive method provides a means for substantially suppressing the formation of cyclic ethers and for obtaining a polymer with a narrow molecular weight distribution by keeping the concentration of carboxylic acid anhydrides or alkylene oxide constantly below 1 wt. % during polymerization. The catalysts have a long life span and lead to polymers that are characterized by highly uniform properties and a narrow molecular weight distribution even if a fairly impure monomer is used. The catalysts are characterized in their granulated form by a previously unknown activity and they form polymers having a very narrow molecular weight distribution and very low color index and acid number.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.