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Effect of phase transitions on the rheology of polymers
Author(s) -
Winter H. Henning
Publication year - 1993
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19930690119
Subject(s) - thermotropic crystal , rheology , liquid crystal , polymer , phase transition , materials science , viscoelasticity , relaxation (psychology) , phase (matter) , chemical physics , glass transition , crystallization , copolymer , polymer chemistry , thermodynamics , polymer science , liquid crystalline , chemistry , organic chemistry , composite material , physics , psychology , social psychology , optoelectronics
Polymeric materials near phase transition conditions exhibit some common features in their linear viscoelastic relaxation patterns. This has been shown by comparing several recent experimental studies of our laboratory. A universal pattern seems to evolve in the case of liquid‐to‐solid transitions such as chemical gelation, crystallization of semi‐crystalline polymers, and nematic to smectic transition in thermotropic liquid crystalline polymers. They all exhibit the self‐similar CW‐spectrum at low frequencies (for ω→0) or long times. Phase separating di‐block copolymers and polymer blends also show this same type of relaxation time spectrum, however, it most likely does not extend to ω→0 and it does not seem to be restricted to the close vicinity of the transition.