Degradation and cis-to-trans isomerization of poly[(2,4-difluorophenyl)acetylene]s of various initial molecular weight: SEC, NMR, DLS and EPR study

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F13%3A00421909" target="_blank" >RIV/61388955:_____/13:00421909 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.polymdegradstab.2013.05.020" target="_blank" >http://dx.doi.org/10.1016/j.polymdegradstab.2013.05.020</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.polymdegradstab.2013.05.020" target="_blank" >10.1016/j.polymdegradstab.2013.05.020</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Degradation and cis-to-trans isomerization of poly[(2,4-difluorophenyl)acetylene]s of various initial molecular weight: SEC, NMR, DLS and EPR study

Popis výsledku v původním jazyce

Molecular weight (MW) and configurational stabilities of a series of high-cis poly[(2,4-difluorophenyl)acetylene]s (PdFPhA, Mw from 2.2 104 to 9.7 105) exposed to the atmosphere and diffuse daylight are reported. Polymers dissolved in THF-d8 undergo simultaneous cis-to-trans isomerization and degradation under formation of a bimodal MW distribution. Degradation and isomerization rates are tightly connected and decrease with decreasing MW of the parent PdFPhAs. This finding may be interesting for the functional applications of substituted polyacetylenes. The partly aged PdFPhAs contain two separable fractions: higher-MW high-cis macromolecules containing a low amount of unpaired electrons and lower-MW deeply isomerized cis/trans macromolecules enrichedin the unpaired electrons content. The difference in MW of these fractions reflects the various degradation rates of isomerized and high-cis macromolecules. Only a slow degradation without changes in the configurational structure proceeds

Název v anglickém jazyce

Degradation and cis-to-trans isomerization of poly[(2,4-difluorophenyl)acetylene]s of various initial molecular weight: SEC, NMR, DLS and EPR study

Popis výsledku anglicky

Molecular weight (MW) and configurational stabilities of a series of high-cis poly[(2,4-difluorophenyl)acetylene]s (PdFPhA, Mw from 2.2 104 to 9.7 105) exposed to the atmosphere and diffuse daylight are reported. Polymers dissolved in THF-d8 undergo simultaneous cis-to-trans isomerization and degradation under formation of a bimodal MW distribution. Degradation and isomerization rates are tightly connected and decrease with decreasing MW of the parent PdFPhAs. This finding may be interesting for the functional applications of substituted polyacetylenes. The partly aged PdFPhAs contain two separable fractions: higher-MW high-cis macromolecules containing a low amount of unpaired electrons and lower-MW deeply isomerized cis/trans macromolecules enrichedin the unpaired electrons content. The difference in MW of these fractions reflects the various degradation rates of isomerized and high-cis macromolecules. Only a slow degradation without changes in the configurational structure proceeds

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CF - Fyzikální chemie a teoretická chemie

OECD FORD obor

—

Projekt

<a href="/cs/project/GAP108%2F11%2F1661" target="_blank" >GAP108/11/1661: Organické nanoporézní polymery odvozené od arylacetylenů jako materiály pro skladování vodíku</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2013

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Polymer Degradation and Stability

ISSN

0141-3910

e-ISSN

—

Svazek periodika

98

Číslo periodika v rámci svazku

9

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

13

Strana od-do

1814-1826

Kód UT WoS článku

000323464200035

EID výsledku v databázi Scopus

—