E-viri
Recenzirano
-
Nikitin, Anatoly N; Hutchinson, Robin A; Buback, Michael; Hesse, Pascal
Macromolecules, 11/2007, Letnik: 40, Številka: 24Journal Article
A novel method to extract individual free-radical polymerization rate coefficients for butyl acrylate intramolecular chain transfer (backbiting), k bb, and for monomer addition to the resulting midchain radical, , is presented. The approach for measuring k bb does not require knowledge of any other rate coefficient. Only the dispersion parameter of SEC broadening has to be determined by fitting measured MWDs or should be available from separate experiments. The method is based upon analysis of the shift in the position of the inflection point of polymer molecular weight distributions produced by a series of pulsed-laser polymerization (PLP) experiments with varying laser pulse repetition rate. The coefficient k bb is determined from the onset of the sharp decrease of the apparent propagation rate coefficient ( ) with decreasing repetition rate, an approach verified by simulation. With experiments performed between −10 and +30 °C, the estimated values are fitted well by an Arrhenius relation with pre-exponential factor A(k bb) = (4.84 ± 0.29) × 107 s-1 and activation energy E a(k bb) = (31.7 ± 2.5) kJ·mol-1. At low pulse repetition rates, the experimental values are related to an averaged propagation rate coefficient, , that is dependent on the relative population of chain-end and midchain radicals. Evaluated by comparing simulated and experimental molecular weight distributions, provides an estimate for . The Arrhenius parameters are: A( ) = (1.52 ± 0.14) × 106 L·mol-1·s-1 and E a( ) = (28.9 ± 3.2) kJ·mol-1.
Vnos na polico
Trajna povezava
- URL:
Faktor vpliva
Dostop do baze podatkov JCR je dovoljen samo uporabnikom iz Slovenije. Vaš trenutni IP-naslov ni na seznamu dovoljenih za dostop, zato je potrebna avtentikacija z ustreznim računom AAI.
Leto | Faktor vpliva | Izdaja | Kategorija | Razvrstitev | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Baze podatkov, v katerih je revija indeksirana
Ime baze podatkov | Področje | Leto |
---|
Povezave do osebnih bibliografij avtorjev | Povezave do podatkov o raziskovalcih v sistemu SICRIS |
---|
Vir: Osebne bibliografije
in: SICRIS
To gradivo vam je dostopno v celotnem besedilu. Če kljub temu želite naročiti gradivo, kliknite gumb Nadaljuj.