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Crystallization and Physical Ageing of Poly (2‐vinyl pyridine)‐ b ‐poly(ethylene oxide) Diblock Copolymers
Author(s) -
Córdova Miguel,
Lorenzo Arnaldo T.,
Müller Alejandro J.,
Fragouli Panagiota,
Iatrou Hermis,
Hadjichristidis Nikos
Publication year - 2010
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.201050114
Subject(s) - crystallization , nucleation , materials science , copolymer , amorphous solid , ethylene oxide , glass transition , polymer chemistry , chemical engineering , phase (matter) , oxide , isothermal process , transmission electron microscopy , composite material , polymer , crystallography , thermodynamics , chemistry , organic chemistry , nanotechnology , physics , engineering , metallurgy
Summary: A set of melt miscible Poly(2‐vinyl pyridine)‐ b ‐Poly(ethylene oxide) (P2VP‐ b ‐PEO) block copolymers of different compositions were studied. Transmission electron microscopy shows phase separation in the materials during the crystallization process of the PEO block as crystalline lamellae are observed for all compositions evaluated. The isothermal crystallization kinetics of PEO is progressively retarded as the P2VP content in the copolymer increases, since P2VP hinders molecular mobility in the miscible amorphous phase. Polarized light optical microscopy demonstrated that the glassy P2VP block has a negative effect on the secondary nucleation of the PEO. Finally, physical ageing experiments performed in the glassy state of the amorphous mixed phase, at different ageing times, demonstrated that a nucleating effect can be induced in the glassy state as a consequence of the reorganization of the amorphous regions. This nucleating effect significantly alters the cold crystallization rate upon subsequent heating above the glass transition temperature.