Transient decay studies of photophysical processes in aromatic polymers. 7. Studies of the molecular weight dependence of intramolecular excimer formation in polystyrene and styrene-butadiene block copolymers

1983 ◽  
Vol 16 (10) ◽  
pp. 1597-1601 ◽  
Author(s):  
D. Phillips ◽  
A. J. Roberts ◽  
G. Rumbles ◽  
I. Soutar
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Molecular Weight Dependence ◽  
Aromatic Polymers ◽  
Intramolecular Excimer ◽  
Excimer Formation ◽  
Photophysical Processes ◽  
Styrene Butadiene

Viscoelastic Behavior of Styrene-Butadiene-Styrene Block Copolymers in Temperature Range of Glass-Rubber Transition of Styrene Block

1996 ◽  
Vol 69 (1) ◽  
pp. 73-80 ◽  
Author(s):  
N. Nakajima
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Viscoelastic Behavior ◽  
Shear Mode ◽  
Molecular Weight Polymer ◽  
Styrene Butadiene Styrene ◽  
The Difference ◽  
Tan Δ ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Abstract Dynamic mechanical measurements were performed with styrene-butadiene-styrene (SBS) block copolymers, Kraton D-1101 and D-l 102. Isochronal data were obtained from −130 to 85°C in the tensile mode at 1 Hz and from 60 to 160°C in the shear mode at 1 rad/s. The isothermal measurements were also performed at 60, 90, 120, 140, and 160°C in the frequency range of 0.0316 to 100 rad/s. The results suggest that the two polymers have different morphologies although the styrene content and the diblock content are about the same for both polymers. Kraton D-1101, which has 1.5 times higher molecular weight, has 3–5 times higher rubbery modulus, compared to D-1102. The lower molecular weight polymer, D-1102, appears to have a larger amount of the mixed phase at the boundary. This is suggest by the lower temperature of the “domain disruption”, Tdd and the higher magnitude of tan δ at Tdd. This explains the difference in the rubbery moduli of the two polymers.

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