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Low temperature dynamic mechanical properties of polyurethane‐polyether block copolymers
Author(s) -
Illinger J. L.,
Schneider N. S.,
Karasz F. E.
Publication year - 1972
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760120104
Subject(s) - materials science , copolymer , elastomer , polyurethane , dynamic mechanical analysis , relaxation (psychology) , polymer , glass transition , composite material , modulus , plateau (mathematics) , atmospheric temperature range , dynamic modulus , polymer chemistry , thermodynamics , psychology , social psychology , mathematical analysis , physics , mathematics
Dynamical mechanical relaxation spectra of a number of polyurethane‐polyether block copolymers have been studied as a function of composition, temperature and frequency. At low temperatures these copolymers are characterized by a high glass‐like modulus which decreases to a much lower typically elastomeric value in a narrow temperature range. The latter is a function in certain cases of the composition of the polymer. The rubbery plateau is maintained up to at least 140°C. In addition, a secondary relaxation is observed around −130°C. These observations can be interpreted in terms of an overall structure consisting of a polyether matrix containing segregated polyurethane domains, the latter serving as physical crosslinks in the system at ambient temperatures and above.