Dresden 2003 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 1: Polymerschmelzen
CPP 1.9: Vortrag
Montag, 24. März 2003, 12:00–12:15, ZEU/160
Relaxation dynamics of entangled branched polymers investigated by SANS — •Martine Heinrich1, Wim Pyckhout-Hintzen1, Dieter Richter1, and Ekkehard Straube2 — 1FZ Jülich, IFF, D-52425 Jülich, Germany — 2Uni. Halle, FB Physik, D-06099 Halle, Germany
We present a study of the relaxation of uniaxially strained H- shaped polymer melts by small angle neutron scattering. With this technique, one can get informations concerning the relationship between the microscopic details of branched polymers dynamics and their enhanced ease of processing compared to linear structures. A model compound for long chain branching (H-shaped) was investigated in elongational flow as a function of time after a step strain of 2. The structure function was measured after specific relaxation times intimately connected to the microscopic hierarchy of the polymer structure. A description of the correlation hole effect and quenched disorder in the scattering in the random phase approximation was adopted from the similarity with permanent rubberelastic networks and modified to permit the observation of strain locally along the faster relaxing arms.