Anionic polymerization of conjugated dienes in the presence of hindered triaryl boron or aluminum derivatives
US4518753A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1983 |
| Grant date | May 21, 1985 |
| Priority date | — |
| Expiry date | Apr 15, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F36/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for the anionic polymerization of a conjugated 1,3-diene in a polar solvent consists of contacting the 1,3-diene with an organo alkali or alkaline earth metal initiator and a sterically hindered Lewis acid, allowing the 1,3-diene to polymerize in the polar solvent and terminating the polymerization reaction. Preferably the Lewis acid is a substituted triaryl derivative of a Group III element, especially boron. However in certain cases (e.g. where the aryl derivative itself is large) the Lewis acid may be an unsubstituted triaryl derivative of a Group III element. Suitable Lewis acids include trimesityl boron and tri (2,6-dimethylphenyl) boron. In preferred embodiments of the present process the 1,3-diene is butadiene, the polar solvent is tetrahydrofuran and the initiator is a difunctional initiator, especially an electron transfer reagent. The main advantages of the present process are that polymers with enhanced 1,4-content, a narrow molecular weight distribution and, in the case of telechelic polymers, with an enhanced difunctional specificity are obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.