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Structure of Polybutadienes Synthesized with a New Catalyst System, 2. Blends of trans‐ and cis‐ 1,4‐Polybutadiene
Author(s) -
Antipov Evgueni M.,
Mushina Evguenia A.,
Stamm Manfred,
Fischer Erhard W.
Publication year - 2001
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20010101)202:1<73::aid-macp73>3.0.co;2-3
Subject(s) - polybutadiene , mesophase , differential scanning calorimetry , materials science , polymer chemistry , glass transition , monoclinic crystal system , copolymer , endothermic process , crystal structure , crystallography , phase (matter) , chemical engineering , chemistry , polymer , organic chemistry , thermodynamics , composite material , physics , adsorption , engineering
The structure, composition and temperature behaviour of polybutadienes prepared with binuclear metal complex catalysts immobilized on a solid carrier are investigated by differential scanning calorimetry, infra‐red spectroscopy and X‐ray scattering. Polybutadienes of nascent structure are blends of trans ‐1,4‐ and cis‐ 1,4‐homopolymers, whereas 1,2‐units are randomly distributed in both macromolecules. The blends exhibit two‐step melting characteristics for the crystalline trans‐ 1,4‐polybutadiene: the low‐temperature transition from the monoclinic crystal form to the pseudohexagonal mesophase and the high‐temperature transition from mesophase to the melt. A bimodal character of the endothermic maximum in DSC traces was observed for the former transition. In addition, it was shown that the nascent blend treated by hot toluene posseses a three‐phase structure and contains, besides the well‐known trans‐ 1,4‐polybutadiene crystalline and amorphous phases, an additional phase component of unknown structure.