Structure and properties of a styrene–butadiene–styrene block copolymer

Abstract

Electron‐microscopic texture and physical properties of a styrene–butadiene–styrene (SBS) block copolymer obtained by casting from toluene, carbon tetrachloride, ethyl acetate, and methyl ethyl ketone are discussed. Two peaks are observed in the mechanical loss (tan delta;) curve at −70 and 100°C which are attributed to segmental motion of polybutadiene and polystyrene, respectively. The polybutadiene peak heights are in the order of solubility in the solvent used; the polystyrene peak heights are in converse order. In addition to these peaks, a third peak is observed at 10°C for specimens cast from ethyl acetate or methyl ethyl ketone. A transition corresponding to this peak is also noticed in thermal analysis. It is proposed that aggregation of styrene blocks is relatively incomplete in specimens cast from solution in poor solvents.

Phase Separation and Mechanical Properties of an Amorphous Poly(ether-b-ester)

“…The differences between the temperatures of these two maxima and the Tgs of the blocks if complete phase separation had occurred are shown in Table III This dependence of block polymer property on casting solvent also is seen in poly ( styrene-b-diene ) polymers (28). Theoretical work (23) has shown that the thermodynamically most stable morphology for a From the same evidence as above it may be deduced that there is a continuous 3IGT matrix with dispersed PPO-rich regions.…”

Organic hybrid of chlorinated polyethylene and hindered phenol. III. Influence of the molecular weight and chlorine content of the polymer on the viscoelastic properties

“…Thus, it was confirmed that the first peak was attributable to the glass transition of the matrix polymer CPE. In some incompatible systems, such as polymer blends, 15 copolymers, 16 and plasticized polymers, 17 the maximum value of the tan ␦ peak of one component decreases by blending with another component. However, the addition of a small amount of AO-80 results in the maximum value of the first peak becoming larger than that of pure CPE1 or CPE2.…”

Elastomer Blends

“…Moore [37] and Keskkula and Traylor [38] have used such methods to study rubber-reinforced polystyrenes, while Miyamoto et al [39] have used them together with dynamic loss (tan δ) measurements to investigate the structure and properties of styrene-butadiene-styrene (S-B-S) block copolymers. Moore [37] and Keskkula and Traylor [38] have used such methods to study rubber-reinforced polystyrenes, while Miyamoto et al [39] have used them together with dynamic loss (tan δ) measurements to investigate the structure and properties of styrene-butadiene-styrene (S-B-S) block copolymers.…”

“…Investigations of the influence of casting solvent on phase morphology [39,205,212,215,219] indicate that the use of a selective good solvent for a given block component tends to favor the development of that component as a continuous matrix (see Fig. 12).…”