Butadiene-Styrene Elastomers:From Sodium-Catalyzed Copolymerizations

Physical Properties of Sodium-Catalyzed Polymers

“…However, the low temperature properties of the experimental elastomers were poorer than those of GR-S vulcanizates, as evaluated by brittle point values and Young's modulus determined at low temperature. An independent study of the processing and physical properties of sodium-catalyzed 75/25 butadiene/styrene copolymer by Schulze and coworkers (27) confirmed these results.…”

Relationship between Molecular Structure and Physical Properties

“…The determination of the way in which the monomer units are linked together to form the long polymer molecules in various elastomers is a subject of considerable interest which has been attacked by a variety of methods (1,34,34,43,44,50). Variations in the details of chain structure must be invoked to explain differences in the properties of polymers made from the same monomers, if these differences cannot be explained by such things as variations in molecular weight distribution or cross linking.…”

Elastomers

“…In sodium-catalyzed copolymerization of butadiene and styrene the styrene is the more reactive monomer whereas in the emulsion system it is the less reactive monomer (84). The process is facilitated by the use of a hydrocarbon diluent to control the heat of the reaction and a wash mill to remove residual catalyst from the copolymer (85). The products are superior to emulsion-polymerized copolymers in flex life and processing characteristics but are inferior in low temperature embrittlement.…”