A study of the mechanical and optical properties of the tri-block copolymer of styrene with butadiene

Abstract Temperature dependences of the mechanical loss tangent, photoelastic coefficient e and birefringence, Δn , of isometric samples of butadiene-styrene block components with 45% polystyrene (PS) were studied. At 120°, melting of the superlattice of the block copolymer, accompanied by a substantial decrease in the e and Δn values, was found to occur. The differences between the process of melting for superlattice copolymers, containing 45 and 27% of PS phase are discussed.