Comments on the determination of absolute rate constants in anionic polymerization

✍ Scribed by S. Bywater

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 127 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199805)36:7<1065::aid-pola4>3.0.co;2-1

✦ Synopsis

Claims have recently been made that absolute rate constants for chain propagation of the unassociated active centers can be made in systems where a high degree of association is present. Anionic polymerization of styrene in nonpolar solvents with lithium as counterion is a typical case. The conditions required to obtain these constants (and the associated aggregate dissociation constants) are described using data from styrene polymerization with lithium and potassium as counterions and data from o-methoxystyrene polymerization. The conclusion reached must be that the k p and K ds values obtained for styrene with counterion lithium cannot be obtained from existing literature data and are simply artifacts of the computer analysis.