Graft copolymerization in supercritical media
US5663237A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 15, 1995 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | Jun 15, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/941
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A supercritical graft copolymerization process is described which includes the steps of: adding a polymer into a high pressure reactor; adding a free radically polymerizable monomer into the reactor; adding a free radical polymerization initiator; adding a sufficient amount of a supercritical solvent to dissolve at least a portion of the polymer and the monomer when supercritical conditions are achieved inside the reactor; and heating and pressurizing the reactor to achieve supercritical conditions therein for a time sufficient to effect a graft copolymerization on the polymer by the polymerizing monomer which forms at least one side chain on the polymer. In general, the reaction pressure will range from 70 atm. to 200 atm. and the reaction temperature will range from 50.degree. C. to 90.degree. C. In the examples provided above, the supercritical solvent was carbon dioxide. However, there is no need to limit the application to such in that the process steps will be equally applicable to other supercritical solvents which have the ability to dissolve at least a portion of the polymer and grafting monomer when at supercritical conditions in the reactor. In general, the reaction time…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.