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Synthesis and Characterization of New Organosoluble Polyamides and Polyimides Based on 2,2‐Bis[4‐ (4‐aminophenoxy)‐3,5‐dimethylphenyl]‐ hexafluoropropane
Author(s) -
Liaw DerJang,
Liaw BeenYang,
Cheng YingChi
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<1625::aid-macp1625>3.0.co;2-o
Subject(s) - polymer chemistry , tetrahydrofuran , solubility , monomer , glass transition , polymer , thermal stability , polyimide , materials science , polyamide , condensation polymer , inherent viscosity , pyridine , diamine , chemistry , organic chemistry , solvent , intrinsic viscosity , layer (electronics)
A new hexafluoro‐containing diamine monomer, 2,2‐bis[4‐(4‐aminophenoxy)‐3,5‐dimethylphenyl]hexafluoropropane ( TBAPHP ), was synthesized in three steps, starting from hexafluoroacetone sesquihydrate and 2,6‐xylenol. The monomer was reacted with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to produce a series of polyamides and polyimides, respectively. The polyamides were prepared under Yamazaki reaction conditions. The polyimides were prepared by a two‐stage procedure that included a ring‐opening polyaddition yielding poly(amic acid)s, followed by a cyclodehydration to polyimides. The obtained polymers had inherent viscosities of 0.52–0.82 dL·g –1 . All of the polymers dissolved in polar solvents, such as N ‐methyl‐2‐pyrrolidinone, N,N ‐dimethylacetamide, and N,N ‐dimethylformamide. The polyimides derived from 4,4′‐oxydiphthalic anhydride and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride exhibited an excellent solubility and were dissolved in cyclohexanone, pyridine, tetrahydrofuran, and chloroform. These polymers showed glass transition temperatures of 231–301°C and decomposition temperatures at 10% weight loss ranging from 470 to 495°C in nitrogen and from 473 to 505°C in air. The tough and flexible polymer films obtained from solution casting showed tensile strengths of 78–96 MPa and tensile moduli of 2.0–2.4 GPa. Polymers containing methyl substituents had higher solubilities and T g values than those without methyl substituents. In addition, the hexafluoroisopropylidene‐containing polymers exhibited a higher solubility and thermal stability than those containing isopropylidene units. UV‐visible absorption spectra revealed that the polyimides showed a better transparency than the polyamides.