Bulk reactive extrusion polymerization process producing aliphatic ester polymer compositions
US5969089A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1997 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Sep 8, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L67/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A bulk extrusion polymerization process to derive an aliphatic polyester from a suitable ester monomer, preferably .epsilon.-caprolactone. Novel reaction formulations containing less than 100 ppm water and having an acid value less than 0.5 mg KOH/g and preferably less than 0.2 mg KOH/g enable the polymerization of bulk monomer in an extruder in a resident time of less than 2 minutes. Different catalyst and initiator systems, processing protocols, and screw configurations lead to the preferred manufacture of poly(.epsilon.-caprolactone) polymer of number average molecular weight, M.sub.n, greater than 100,000. A novel poly(.epsilon.-caprolactone) intermediate optionally grafted to starch, is described which has significantly different processing and use characteristics as compared to a straight-chain polycaprolactone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.