Chain-extended or crosslinked polyethylene oxide/polypropylene oxide/polyethylene oxide block polymer with optional polyester blocks
US6579951B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2000 |
| Grant date | Jun 17, 2003 |
| Priority date | — |
| Expiry date | Sep 18, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2205/05
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A composition exhibiting reverse thermal gellation properties comprises a block polymer having the structure:{[An(BCB)An]}mwherein A is a polyester unit, B is a poly(ethylene oxide) unit, C is a poly(propylene oxide unit, E is a chain extender or crosslinking agent unit, n ranges from 0 to 20, and m is greater than 2, said block polymer possessing an EO (ethylene xide):PO (propylene oxide) ratio ranging from about 0.2:1 to about 40:1, said composition having a final viscosity at a final temperature of more than twice the initial viscosity at an initial temperature, said final temperature being at least 10° C. higher than said initial temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.