The general link between random scissions in linear polymers, changes in average chain length and the Mark-Houwink equation
2005 (English)In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 88, no 2, 159-167 p.Article in journal (Refereed) Published
Theories for random scission degradation of polymers are motivated from the basic scientific interest in reaction kinetics and yields of process. There is a tradition to derive scission-measures (bond consumption or cleavage) from the number average of chain length in a molecular weight distribution. It is understood by many that the validity of these derivations will be conditional and many attempts are made to extend the accuracy of the models. This article presents a mass-based derivation for changes in chain length that offers scission-values not only from number averages but also from the mass and viscosity averages, independent of molecular weight distribution profile. The derivation shows the interdependence between the Mark-Houwink equation and scission calculus. The exponent in the Mark-Houwink equation is proposed to originate from the process of varying polymer chain lengths for calibration and the initial content of polymer chain ends in the sample as well as the earlier proposed effects from chain curl. Calculation of the number of random scission hence demands the Mark-Houwink parameters to be calibrated by varying polymer chain lengths using random scission generation.
Place, publisher, year, edition, pages
2005. Vol. 88, no 2, 159-167 p.
polymer degradation, radiolytic degradation, cellulose, number average, mass average, viscosity average, scissions, bond consumption, paper permanence, degradation, cellulose, prediction
IdentifiersURN: urn:nbn:se:kth:diva-14634DOI: 10.1016/j.polymdegradstab.2003.09.022ISI: 000227915900001ScopusID: 2-s2.0-14544289902OAI: oai:DiVA.org:kth-14634DiVA: diva2:332675
QC 201005252010-08-052010-08-05Bibliographically approved