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PO: Polymerphysik
PO 9: Poster: Copolymere und Polymermischungen
PO 9.9: Poster
Monday, March 17, 1997, 15:30–17:30, Gg
Pressure Induced Microphase Separation Transition in Symmetric Diblock Copolymer Melts — •H. Ladynski1, V. Bartels2, P. Lindner1, and M. Stamm2 — 1Institut Laue Langevin, 156 Av. des Martyrs, BP 156, 38043 GRENOBLE CEDEX 9 (France) — 2Max-Planck-Institut f"ur Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany)
The pressure dependence of the microphase separation transition (MST) in poly(styrene-b-paramethylstyrene) and poly(styrene-b-butadiene) has been investigated in situ by small angle neutron and X-ray scattering using a high pressure cell. The temperature dependent phase behaviour of these materials at atmospheric pressure is well known from previous experiments and can therefore be compared. It has been found in both materials that a pressure induced MST from the disordered to the ordered regime at a constant temperature takes place. The transition is indicated by an increase of maximal intensity and a decrease of FWHM. This leads to the conclusion that pressure increases the MST temperature in both systems (about appr. 1∘ C / 35 bar in P(S-b-pMS)). Furthermore the conformational behaviour of the single chain or single block in P(S-b-pMS) has been observed by SANS using appropriate labelling by deuteration.