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Synthesis of New Epoxy Liquid‐Crystalline Monomers with Azo Groups in the Central Mesogenic Core. Crosslinking with Amines
Author(s) -
Castell Pere,
Galià Marina,
Serra Angels
Publication year - 2001
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 - 10.1002/1521-3935(20010601)202:9<1649::aid-macp1649>3.0.co;2-x
Subject(s) - mesogen , thermogravimetric analysis , liquid crystal , differential scanning calorimetry , thermal stability , epoxy , materials science , curing (chemistry) , polymer chemistry , monomer , thermosetting polymer , chemistry , organic chemistry , composite material , polymer , liquid crystalline , physics , optoelectronics , thermodynamics
A new class of liquid‐crystalline epoxy resins containing azomethine and azo groups was synthesized and structurally characterized. The liquid crystal behavior of these compounds was characterized by differential scanning calorimetry (DSC), hot‐stage polarized optical microscopy (POM) and wide‐angle X‐Ray diffraction (WAXS). An aliphatic spacer between the mesogenic aromatic central core and the glycidyl groups favors the formation of different types of smectic mesophases with a wide range of stability. The LC resins were cured to obtain liquid crystal thermosets (LCTs). The cure was tested using aromatic primary diamines as curing agents and nematic‐like networks were obtained. When tertiary amines were used catalytically, smectic C‐like networks were retained when the spacer length had four methylene units or more. The polydomain ordered materials obtained were characterized by WAXS and their thermal stability was tested by thermogravimetric analysis (TGA).