Makromol. Chem. 192, 1235 -1236 (1991)
Makromol. Chem. 190,3269-3284 (1989)
Nematic elastomers: The influence of external mechanical
stress on the liquid-crystalline phase behavior
Joachim Schatzle, Wolfgang Kaufhold, Heino Finkelmann *
(Date of receipt: February 4, 1991)
As a result of an error in the evaluation programme, the values represented in Figs.
5, 6, 7 and 8 for the birefringence and mechanical stress are not correct. The correct
values of the measurements are represented in the new Figs. 5, 6, 7 and 8.
The new Fig. 5 shows the plot of birefringence against the applied stress for different
temperatures. The theory of Kuhn and Grun predicts for conventional rubbers a linear
relation between birefringence and stress. There is no deviation from this linearity until
the lowest temperature T = Tn,i + 4K. In Figs. 6 and 7, no quantitative change is
observable. However, the quantitative values for the birefingence and the mechanical
stress have changed. The dependence of T* on the applied stress is shown in Fig. 8. This
dependence between the hypothetical second-order phase transformation temperature
T* and the external field is now linear. In Figs. 2, 3, 9, and 10, the nominal stresses
plotted are too high by a factor of two.
' i , is defined as force per unit actual, strained cross-section
Birefringence An vs. reduced temperature Tred at different stress levels ' i , . Sample 4a
Birefringence An vs. true stress 0 ,
for different reduced temperatures Tred. Sample 4a.
0 1991, Hiithig & Wepf Verlag, Basel
CCC 0025-1 16X/91/$03.00
J. Schatzle, W. Kaufhold, H. Finkelmann
Fig. 7. Reciprocal birefrin-
gence An-' vs. reduced tem-
perature Tnd . Sample 4a.
6,: (*): 1,o. 10-2, (+):
N . mm-'
Fig. 8. Phase transforma-
tion temperature T* vs. true
stress ow for sample 4a