TRANSPARENT (LIKE GLASS) HIGH-IMPACT POLYSTERENE ON BASE OF BUTADIENE-STYRENE BLOCK COPOLYMERS Russian patent published in 2005 - IPC

FIELD: block copolymers containing at least two rigid blocks formed by vinyl aromatic monomers.

SUBSTANCE: proposed copolymer has at least two rigid blocks formed by vinyl aromatic monomers and at least one static soft block formed by dienes and vinyl aromatic monomers; soft block containing at least 20% of 1,2-vinyl is located between rigid blocks; fraction of rigid blocks is equal to 51-74mass-% in terms of entire block copolymer. Block copolymers are obtained through anion polymerization; polymerization of soft block is performed in presence of potassium salt. Transparent glass-like polysterene thus obtained is characterized by elasticity modulus of 753 Mpa, tensile stress of 18.2 Mpa, breaking stress of 33.6 Mpa, elongation at rupture of 373%, Shore hardness of 66 and softening temperature (by Vieat) of 44.6°C. Proposed block copolymers possess good compatibility with styrene polymers and may be used for production of fibers, films and molded units.

EFFECT: enhanced efficiency.

15 cl, 9 tbl, 27 ex