Anionic polymerization of purified monovinylidene aromatic monomer feed stock
US4883846A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 1987 |
| Grant date | Nov 28, 1989 |
| Priority date | — |
| Expiry date | Apr 20, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F12/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The specification discloses a monovinylidene aromatic polymer having a molecular weight of at least 50,000 and an extremely narrow molecular weight distribution of less than 1.5, preferably with at least 80% by weight of the polymer having a molecular weight within plus or minus 30% of the weight average molecular weight. This polymer is produced through anionic polymerization of a pure feed stock which is first cooled to a temperature at which an anionic initiator preferentially reacts with impurities present in the feed stock and initiates the polymerization reaction but does not substantially propagate styrene polymerization. The initiator is uniformly dispersed into the feed stock while maintaining it at the lower temperature and the feed stock temperature is subsequently increased to a temperature at which polymerization of the sytrene proceeds normally. The resulting polymer is especially well adapted to injection molding in that exceptional strength properties are achieved in combination with good processability, e.g., melt flow rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.