The influence of the Poissonian character of chain growth on propagation probabilities in free radical polymerization with chain-length dependent termination

✍ Scribed by Oskar Friedrich Olaj; Gerhard Zifferer; Andreas Kornherr

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 457 KB
• Volume: 7
• Category: Article
• ISSN: 1022-1344
• DOI: 10.1002/(sici)1521-3919(19980501)7:3<321::aid-mats321>3.0.co;2-#

✦ Synopsis

It is shown that the (established) method of deriving chain-length distributions from propagation probabilities is not fully consistent with the Poissonian character of chain propagation if termination is chain-length dependent: the fluctuation of chain propagation leads to somewhat lower radical concentrations (rates of propagation). The deviation is the more prominent the more important is the role assigned to the shorter one of the two chains involved in the termination process by the model applied.

Various methods are in use for calculating chain-length distributions (CLDs) from kinetic schemes for free radical polymerization'.*). A large group of them somehow is based on the solution of the system of simultaneous differential equations. A different method -to be traced back to G.V. Schulz3) -which is also described in ref.'), introduces steady-state conditions in an early stage of cal-