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PO: Polymerphysik

PO 7: Poster: Polymere Netzwerke

PO 7.4: Poster

Dienstag, 2. März 1999, 14:00–16:00, Foyer

In Situ Cross-linking Reaction Investigation for the PI+DCP System — •Alberto Botti¹, Mahmoud Goad¹, Wim Pyckhout-Hintzen¹, Dieter Richter¹, and Ekkehard Straube² — ¹IFF Forschungszentrum Juelich 52425 Juelich — ²University Halle 06099 Halle

An in situ investigation of the random cross-linking process in Polyisoprene ( PI) by SANS and rheological measurements is presented. The attention is focuse d on the scission processes of the polymeric chains during the reaction with t he cross-linker (DCP) while increasing the temperature from room temperature u p to 411 K. Both techniques are complementary and allow the study of the micro scopic structure of the network near the gel point. The kinetics of the react ion is followed by a stroboscopic storage of the SANS structure factor of a la beled triblock HDH copolymer, and the coordinates of the gel point, in terms o f temperature and reaction time, were identified from the isochronal storage m odulus G’ and the loss modulus G”. It is found that scission processes do not visibly affect the modulus, whereas the SANS data are in perfect agreement to a description of random-scissioning of chains.