caa a22 4500 465813895 CHVBK 20180323112122.0 cr unu---uuuuu 170327e19901101xx s 000 0 eng 10.1007/BF01329301 doi (NATIONALLICENCE)springer-10.1007/BF01329301 Relaxation dynamics of selected polymer chain segments and comparison with theoretical models [Elektronische Daten] [C. Ylitalo, G. Fuller, V. Abetz, R. Stadler, D. Pearson] Simultaneous measurement of infrared dichroism and birefringence is used to study selected polymer segment dynamics in isotopically labeled block copolymers. Two different polymers were studied: polybutadiene and poly (ethylene propylene). The first type consisted of a triblock with a short middle block labeled and a diblock with a short end block labeled, while the second type consisted of a triblock with three equal blocks and the end blocks labeled. Results of step strain experiments at −10°C for polybutadiene and at room temperature for poly(ethylene propylene) indicated that segments located at chain ends relax faster than segments located at chain centers. These experimental data were compared to the predictions of two molecular models: the bead-spring model of Rouse and the tube model of Doi and Edwards, and it was found that both models correctly predict the qualitative features of segmental relaxation. However, the tube-model predictions were closer to the experimental results. In addition, when the effects of orientational coupling interactions between segments in the melt were incorporated into this model, its predictions quantitatively agreed with the experimental results. The orientational coupling coefficient for poly(ethylene propylene) was 0.45 as measured from previous work, and for polybutadiene it was found to be 0.4. Steinkopff, 1990 P olybutadiene nationallicence p oly(ethylene propylene) nationallicence o rientation correlations nationallicence I R dichroism nationallicence R ouse model nationallicence r eptation nationallicence polymer segments dynamics nationallicence Ylitalo C. Chemical Engineering Department, Stanford University, 94305-5025, Stanford, California, USA aut Fuller G. Chemical Engineering Department, Stanford University, 94305-5025, Stanford, California, USA aut Abetz V. Institute for Macromolecular Chemistry, University of Freiburg, FRG aut Stadler R. Institute for Macromolecular Chemistry, University of Freiburg, FRG aut Pearson D. Department of Chemical and Nuclear Engineering and Materials Department, University of California, Santa Barbara, California, USA aut Rheologica Acta Steinkopff-Verlag 29/6(1990-11-01), 543-555 0035-4511 29:6<543 1990 29 397 https://doi.org/10.1007/BF01329301 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01329301 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ylitalo C. Chemical Engineering Department, Stanford University, 94305-5025, Stanford, California, USA aut NATIONALLICENCE 700 1- Fuller G. Chemical Engineering Department, Stanford University, 94305-5025, Stanford, California, USA aut NATIONALLICENCE 700 1- Abetz V. Institute for Macromolecular Chemistry, University of Freiburg, FRG aut NATIONALLICENCE 700 1- Stadler R. Institute for Macromolecular Chemistry, University of Freiburg, FRG aut NATIONALLICENCE 700 1- Pearson D. Department of Chemical and Nuclear Engineering and Materials Department, University of California, Santa Barbara, California, USA aut NATIONALLICENCE 773 0- Rheologica Acta Steinkopff-Verlag 29/6(1990-11-01), 543-555 0035-4511 29:6<543 1990 29 397 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer