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Synthesis and properties of elastomeric poly(propylene)
Author(s) -
Mansel Stefan,
Pérez Ernesto,
Benavente Rosario,
Pereña José M.,
Bello Antonio,
Röll Werner,
Kirsten Robin,
Beck Stefan,
Brintzinger HansHerbert
Publication year - 1999
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/(sici)1521-3935(19990601)200:6<1292::aid-macp1292>3.0.co;2-g
Subject(s) - tacticity , crystallinity , elastomer , materials science , polymer , stress relaxation , polymer chemistry , viscoelasticity , relaxation (psychology) , dynamic mechanical analysis , chemical engineering , composite material , polymerization , creep , psychology , social psychology , engineering
Elastomeric poly(propylene) with low percentages of isotactic pentads and high molecular weight was synthesized using unbridged “oscillating” metallocenes. The polymer sample with the highest [ mmmm ] content (22%) shows a small amount of crystallinity, which is highly influenced by the thermal history, and differs significantly in stress‐strain and dynamic mechanical properties from all other samples. Polymers with lower isotacticity index, although lacking crystallinity in thermal analysis, differ in their viscoelastic behaviour from those of atactic poly(propylene). In dynamic mechanical analysis the γ relaxation at low temperature shows high sensitivity to low isotactic contents.