Synthesis and properties of aromatic polyamides containing the cyclohexane structure

Thermoplastic and organic-soluble aromatic polyamides containing both bulky triphenylethane units and flexible ether linkages were prepared directly from 1,1-bis[4-(4-carboxyphenoxy)phenyl]-1-phenylethane (III) with various aromatic diamines or from 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenylethane (V) with various aromatic dicarboxylic diacids via triphenyl phosphite and pyridine. These polyamides had inherent viscosities ranging from 0.71 to 1.77 dL/g. All the polymers easily were dissolved in aprotic polar solvents such as N-methyl-2-pyrrolidone and N,N-dimethylacetamide, and some even could be dissolved in less polar solvents such as tetrahydrofuran. The flexible and tough films cast from the polymer solutions possessed tensile strengths of 89 to 104 MPa. The polyamides were thermally stable up to 460°C in air or nitrogen. Glass-transition temperatures of these polyamides were observed in a range of 179 to 268°C via differential scanning calorimetry or thermomechanical analysis.

Section: Solubilitysupporting

confidence: 90%

“…This trend was similar to that found in previous papers. [21][22][23] The thermal stability of the polyamides was studied by TG. Typical TG curves in air and nitrogen atmospheres of the representative polymer VII g are shown in Figure 5.…”

Section: Thermal Propertiesmentioning

confidence: 99%

Preparation and characterization of aromatic polyamides based on a bis(ether‐carboxylic acid) or a dietheramine extended from 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane

Hsiao

Yang

Chuang

et al. 2000

“…Polymers VII c and IX c showed a slightly lower solubility because of their symmetrical and rigid biphenylene segments. Similar to the results reported in our preceding articles,21–23 the two set analogous polyamides VII a–d and IX a–d showed a similar solubility behavior. The high solubility of these polyamides was apparently due in part to the presence of the packing‐disruptive triphenylethane unit in the polymer backbone, which resulted in increased chain packing distances and decreased intermolecular interactions.…”

Section: Resultssupporting

confidence: 89%

Preparation and characterization of aromatic polyamides based on a bis(ether-carboxylic acid) or a dietheramine extended from 1,1-bis(4-hydroxyphenyl)-1-phenylethane

Hsiao¹,

Yang²,

Chuang³

et al. 2000

Self Cite

Thermoplastic and organic‐soluble aromatic polyamides containing both bulky triphenylethane units and flexible ether linkages were prepared directly from 1,1‐bis[4‐(4‐carboxyphenoxy)phenyl]‐1‐phenylethane (III) with various aromatic diamines or from 1,1‐bis[4‐(4‐aminophenoxy)phenyl]‐1‐phenylethane (V) with various aromatic dicarboxylic diacids via triphenyl phosphite and pyridine. These polyamides had inherent viscosities ranging from 0.71 to 1.77 dL/g. All the polymers easily were dissolved in aprotic polar solvents such as N‐methyl‐2‐pyrrolidone and N,N‐dimethylacetamide, and some even could be dissolved in less polar solvents such as tetrahydrofuran. The flexible and tough films cast from the polymer solutions possessed tensile strengths of 89 to 104 MPa. The polyamides were thermally stable up to 460°C in air or nitrogen. Glass‐transition temperatures of these polyamides were observed in a range of 179 to 268°C via differential scanning calorimetry or thermomechanical analysis. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 247–260, 2000

“…The bis(ether‐acyl chloride) monomers, 1,1‐bis[4‐(4‐chloroformylphenoxy)phenyl]cyclohexane ( 1a ) (mp 86–87 °C), 5,5‐bis[4‐(4‐chloroformylphenoxy)phenyl]‐4,7‐methanohexahydroindan ( 1b ) (mp 70–72 °C), and 9,9‐bis[4‐(4‐chloroformylphenoxy)phenyl]fluorene ( 1c ) (mp 256–258 °C), were prepared by chlorinating the corresponding bis(ether‐carboxylic acid)s16–18 with thionyl chloride in the presence of one drop of N , N ‐dimethylformamide (DMF) as a catalyst. Details of the synthesis and characterization data of these diacyl chlorides have been described in a separate article 20.…”

Section: Methodsmentioning

confidence: 99%

“…An impressive series of high glass‐transition temperature ( T g ) soluble polymers, referred to as cardo polymers, was pioneered in the early 1960s and reviewed by Korshak et al15 Such polymers contain at least one element in the recurring unit that includes a cyclic side group such as 9,9‐fluorenylidene that imparts a combination of enhanced thermal stability, high T g , and improved solubility. It has been demonstrated in our previous articles16–19 that incorporation of both the ether linkage and cardo units such as 1,1‐cyclohexylidene, 4,7‐methanohexahydroindane‐5,5‐diyl, 2,2‐adamantylidene, and 9,9‐fluorenylidene into the macromolecular backbone results in polyamides and polyimides with improved solubility that retains good thermal properties. In an attempt to improve the processability of PBOs through improved solubility and/or thermoplasticity, we carried out the synthesis of aromatic PBOs via the introduction of ether and cardo groups into the polymer backbone.…”

Section: Introductionmentioning

confidence: 94%

Synthesis and properties of novel cardo aromatic poly(ether‐benzoxazole)s

Hsiao

2001

Self Cite

Three new bis(ether-acyl chloride) monomers, 1,1-bis[4-(4-chloroformylphenoxy)phenyl]cyclohexane (1a), 5,5-bis[4-(4-chloroformylphenoxy)phenyl]-4,7-methanohexahydroindan (1b), and 9,9-bis[4-(4-chloroformylphenoxy)phenyl]fluorene (1c), were synthesized from readily available compounds. Aromatic polybenzoxazoles bearing ether and cardo groups were obtained by the low-temperature solution polycondensation of the bis(ether-acyl chloride)s with three bis(aminophenol)s and the subsequent thermal cyclodehydration of the resultant poly(o-hydroxy amide)s. The intermediate poly(o-hydroxy amide)s exhibited inherent viscosities in the range of 0.35-0.71 dL/g. All of the poly(o-hydroxy amide)s were amorphous and soluble in many organic polar solvents, and most of them could afford flexible and tough films by solvent casting. The poly(o-hydroxy amide)s exhibited glass-transition temperatures (T g 's) in the range of 141-169°C and could be thermally converted into the corresponding polybenzoxazoles approximately in the region of 240 -350°C, as indicated by the DSC thermograms.Flexible and tough films of polybenzoxazoles could be obtained by thermal cyclodehydration of the poly(o-hydroxy amide) films. All the polybenzoxazoles were amorphous and showed an enhanced T g but a dramatically decreased solubility as compared with their poly(o-hydroxy amide) precursors. They exhibited T g 's of 215-272°C by DSC and showed insignificant weight loss before 500°C in nitrogen or air.