Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 40: Polymer Crystallization and Semicrystalline Polymers
CPP 40.5: Vortrag
Donnerstag, 17. März 2011, 11:45–12:00, ZEU 160
Confined dynamics and crystallization in self assembled alkyl nanodomains — •Shireesh Pankaj1 and Mario Beiner1,2 — 1Naturwissenschaftliche Fakultät II, Martin-Luther Universität Halle-Wittenberg, 06099 Halle (Saale), Germany — 2Fraunhofer-Institut für Werkstoffmechanik, Walter-Hülse-Str. 1, 06120 Halle (Saale), Germany
Long alkyl groups are often used to improve the performance of functional polymers. The methylene sequences in such systems usually show a strong tendency to aggregate to form small alkyl nanodomains which can be either completely amorphous or partly crystalline. The influence of main chain packing, domain size and density on the properties of self-assembled alkyl nanodomains is studied based on a comparison of regio-random and regio-regular poly(3-alkyl thiophenes) (P3ATs) with different side chain length as model systems. We show that the dynamics of the CH2 units in amorphous alkyl nanodomains is mainly independent on the packing and microstructure of the main chains. Relaxation spectra show a similar CH2 dynamics despite of the fact that the thiophene main chains are crystalline in regio-regular but amorphous in the regio-random P3ATs. Reasons for the systematic dependence of the CH2 dynamics on the length of the alkyl groups are considered. The influences of average volume per CH2 unit and geometrical confinement are studied. A competition of main and side chain crystallization mechanisms is discussed which should be considered if higher P3ATs are optimized for optoelectronic applications.