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Synthesis of aromatic polybenzoxazoles by silylation method and their thermal and mechanical properties
Author(s) -
Imai Yoshio,
Itoya Kazuo,
Kakimoto Masaaki
Publication year - 2000
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(20001101)201:17<2251::aid-macp2251>3.0.co;2-w
Subject(s) - silylation , condensation polymer , ultimate tensile strength , glass transition , polymer chemistry , amide , trimethylsilyl , materials science , chemistry , organic chemistry , polymer , composite material , catalysis
Abstract Various aromatic polybenzoxazole (PBO) films were prepared through the two‐step silylation method by low‐temperature solution polycondensation of trimethylsilyl‐substituted bis( o ‐aminophenol)s with aromatic dicarboxylic acid chlorides yielding precursor poly( o ‐trimethylsiloxy‐amide)s, followed by thermal cyclocondensation. Four aromatic PBOs had glass transition temperatures ( T g ) in the range of 275–375°C, and the T g values were slightly lower than those of the structurally related polyimides. The temperatures of 10% weight loss of these PBOs ranged from 545–615°C in nitrogen, and the values were somewhat higher than those of the structurally similar polyimides. The films of the PBOs had tensile strengths of 105–135 MPa, elongations at break of 11–25%, and tensile moduli of 2.1–2.8 GPa.