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Aqueous Gels of Diblock Oxyethylene‐Oxypropylene Copolymers
Author(s) -
Kelarakis Antonis,
Havredaki Vassiliki,
Booth Colin
Publication year - 2003
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/macp.200290051
Subject(s) - copolymer , micelle , aqueous solution , polymer chemistry , mesophase , rheometry , materials science , phase (matter) , chemistry , polymer , composite material , organic chemistry
Aqueous solutions of diblock copolymers E 102 P 37 and E 92 P 55 (E = oxyethylene unit, P = oxypropylene unit) were investigated by rheometry. Storage ( G′ ) and loss ( G″ ) modulus and yield stress ( σ y ) were used to detect and characterise hard and soft gels in experiments which covered the concentration range 4–28 wt.‐% copolymer and the temperature range 5–85 °C. Comparison is made with phase diagrams reported for other diblock copoly(oxyalkylene)s, and it is shown that the mesophase behaviour of these systems depends on the effective thickness of the E‐block corona and the stability of the micelles at low temperatures.Hard‐gel boundaries (circles) and soft‐gel boundaries (squares) for aqueous solutions of copolymers (○, □) E 92 P 55 and (•, ▪) E 96 B 18 .