Pulsed laser polymerization: Analytical solutions of the chain length distribution revisited

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

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 138 KB
• Volume: 8
• Category: Article
• ISSN: 1022-1344
• DOI: 10.1002/(sici)1521-3919(19990501)8:3<260::aid-mats260>3.0.co;2-q

✦ Synopsis

A new solution for chain-length distributions of "dead" polymer and their moments (obtained by solving the coupled system of non-linear differential equations in full generality) is presented and compared to existing theoretical and numerical approaches. The new solution for chain-length distributions (cld) (at least numerically) coincides with our earlier results (analytical solution as well as data computed by use of numerical models) which were obtained by starting with strict coupling of time and degree of polymerization followed by an a posteriori Poisson broadening. (As a consequence the new solution also coincides with a numerical treatment based on fluctuating propagation probabilities by introducing an a priori Poisson broadening.) In turn, for termination exclusively by disproportionation this earlier solution is fully equivalent to Aleksandrov's approach (after some modification of the latter expression). This holds true also for termination exclusively by combination if one corrects for errors in Aleksandrov's derivation. The new solution of the moments of the cld agrees with our former results, while Aleksandrov's expressions are shown to be worthless under the usual experimental conditions.