Properties of Random and Block Copolymers of Butadiene and Styrene. III. Three Sequence Styrene-Butadiene-Styrene Block Polymers

1967 ◽  
Vol 40 (4) ◽  
pp. 1183-1199 ◽  
Author(s):  
C. W. Childers ◽  
G. Kraus
Keyword(s):  
Tensile Strength ◽  
Block Copolymers ◽  
Polymer Chains ◽  
Two Phase ◽  
Styrene Copolymers ◽  
Relaxation Measurements ◽  
Styrene Butadiene Styrene ◽  
Increasing Temperature ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Abstract In butadiene styrene copolymers containing long block sequences chain segments associate with like segments to form a two phase structure. Properties of such polymers are dependent not only on composition and molecular weight but also on block sequence along the chain. Polymers containing two or more polystyrene blocks per molecule form networks and exhibit elastomeric properties in the uncured state resembling those of filler reinforced vulcanizates. This behavior is shown both by linear styrene-butadiene-styrene elastomers and multichain block copolymers branched in the polybutadiene blocks. A prominent loss tangent peak was observed around —40° C for the multichain polymers. Stress strain following prestretching and stress relaxation measurements indicate some shifting of polystyrene associations during stretching. Tensile strength is reduced by increasing temperature and addition of plasticizers. Reinforcement by polystyrene domains in vulcanized block copolymers is evident from tensile strength, dynamic modulus, and swelling measurements, but decreases with increased crosslinking. The number of styrene sequences in the primary molecules is less important after vulcanization as crosslinking destroys the individuality of the original polymer chains.

Viscoelastic and Ultimate Tensile Properties of Styrene-Butadiene-Styrene Block Copolymers

1969 ◽  
Vol 42 (5) ◽  
pp. 1257-1276 ◽  
Author(s):  
T. L. Smith ◽  
R. A. Dickie
Keyword(s):  
Tensile Strength ◽  
Block Copolymers ◽  
High Speed ◽  
Extension Rate ◽  
Stress Strain ◽  
Simple Tension ◽  
Ultimate Properties ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Abstract A study was made of the stress—strain and ultimate properties in simple tension of an elastomeric styrene—butadiene—styrene block copolymer (Kraton 101) and also of a similar material (Thermolastic 226) that contains about 35% plasticizer as well as inorganic pigments. Stress—strain data were obtained at crosshead speeds from 0.02 to 20 in./min at temperatures from − 40 to 60° C. The relaxation rate, derived from the data at constant extension rates, was about 8% per decade of time for both materials at temperatures from − 40 to about 40° C and at extensions from about 20% up to 400%. Above − 30° C, the shift factor log aT was found to vary linearly with temperature. These findings indicate that the time and temperature dependence of the mechanical properties results primarily from the plastic (or viscoelastic) characteristics of the styrene domains. The tensile strength for Kraton 101 below 40° C is somewhat greater than 4000 psi, sensibly independent of extension rate and temperature. For the highly plasticized Thermolastic 226, the tensile strength at an extension rate of 1.0 min−1 increases from 2200 psi at 0° C to 3600 psi at − 40° C. Above 40° C for Kraton 101 and above 0° C for Thermolastic 226, the tensile strengths are dependent on extension rate and temperature owing to the increased ductility of the styrene domains. The high strength of these materials results from the uniformly dispersed styrene domains of colloidal dimensions. To obtain a crack of sufficient size to satisfy an energetic criterion for self-sustained high-speed propagation, domains must be disrupted. The plastic characteristics of the domains have a controlling effect on crack growth and thus on the ultimate properties of the materials. The strength and extensibility of other elastomers are considered in relation to those of the block copolymers.

The Results of the Compromise Task Solution Directed for Development of Polymer-Modified Binder

2021 ◽  
Vol 899 ◽  
pp. 67-72
Author(s):  
V.D. Polonik ◽  
A.S. Kukleva ◽  
N.D. Avdeev ◽  
M.D. Shlyaptseva ◽  
Vadim G. Nikol'skii ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Softening Point ◽  
Mutual Influence ◽  
Brittleness Temperature ◽  
Styrene Butadiene Styrene ◽  
Modified Binder ◽  
Styrene Butadiene ◽  
Butadiene Styrene

This work presents the results of optimization compositions of polymer-modified binder (PMB) by a compromise task. The conducted study of influence two prescription factors – containing styrene-butadiene-styrene and sulfur – on which is a set of indicators of polymer-bitumen binders were carried out. The regularities of these factors of mutual influence were established by such indicators as the Fraas brittleness temperature, penetration, softening point, ductility. The dosages of SBS and sulfur have been determined by ensuring the achievement of the required level of PBB indicators in accordance with GOST R 52056-2003 «Bitumen-polymer road binders are based on styrene-butadiene-styrene block copolymers. Specifications».

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.

Morphology of styrene-butadiene-styrene block copolymers

Polymer ◽  
1970 ◽  
Vol 11 (5) ◽  
pp. 268-276 ◽  
Author(s):  
Umberto Bianchi ◽  
Enrico Pedemonte ◽  
Antornio Turturro
Keyword(s):  
Block Copolymers ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Butadiene Styrene
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