Synthesis and characterization of aromatic polyamides derived from various derivatives of 4,4’-oxydianiline
TL;DR: In this paper, three aromatic diamines, 2,2′-diiodo-4,4′-oxydianiline (DI-ODA 2), 2, 2′-bis[p-(trifluoromethyl)phenyl]-4, 4, 4′-xydianile (BTFP)-ODA 3) and 2, 8-diaminodibenzofuran (DADBF 5) were synthesized by using 4,4-oxyniline as the starting material.
Abstract: Three aromatic diamines, 2,2′-diiodo-4,4′-oxydianiline (DI-ODA 2), 2,2′-bis[p-(trifluoromethyl)phenyl]-4,4′-oxydianiline (BTFP-ODA 3) and 2,8-diaminodibenzofuran (DADBF 5) were synthesized by using 4,4-oxydianiline (4,4′-ODA) as the starting material. New aromatic polyamides 6, 7 and 8 were prepared from these three diamines and six commercially available aromatic diacids by direct polycondensation, respectively. Polyamides 6 and 7 contained bulky iodide and p-trifluoromethylphenyl substitutents that would hinder the chain packing and increase the free volume. They exhibited good optical transparency in visible light region and showed excellent solubility in organic solvents such as DMSO, DMAc, DMF and NMP. Polyamides 8 containing planar dibenzofuran moieties had the highest glass transition temperatures and decomposition temperatures among these polyamides. Polyamides 6 had the lowest decomposition temperatures due to the presence of weak carbon–iodine bond. All of these polyamides showed amorphous nature evidenced by wide angle X-ray diffraction. No endothermic peaks were observed from DSC thermograms up to their decomposition temperatures. High optical transparency and excellent solubility combined with good thermal stability make these polyamides attractive for potential soft electronics applications.
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TL;DR: The state of the art following the last 8 years of research into aromatic polyamides, wholly aromaticpolyamides or aramids is described, which has been carried out to take advantage of the mentioned characteristics in advanced fields related to transport applications, optically active materials, electroactive materials, smart materials, or materials with even better mechanical and thermal behavior.
Abstract: We describe herein the state of the art following the last 8 years of research into aromatic polyamides, wholly aromatic polyamides or aramids. These polymers belong to the family of high performance materials because of their exceptional thermal and mechanical behavior. Commercially, they have been transformed into fibers mainly for production of advanced composites, paper, and cut and fire protective garments. Huge research efforts have been carried out to take advantage of the mentioned characteristics in advanced fields related to transport applications, optically active materials, electroactive materials, smart materials, or materials with even better mechanical and thermal behavior.
62 citations
TL;DR: In this article, two diimide-diacid monomers 4,4′-bis[4″-(trimellitimido)phenylisopropylidene-4″′-phenoxy] were synthesized and the structures of the monomers were characterized by FT-IR and 1H-NMR spectroscopy.
Abstract: Two diimide-diacid monomers 4,4′-bis[4″-(trimellitimido)phenyl isopropylidene-4″′-phenoxy]diphenyl sulfone and 4,4′-bis[4″-(trimellitimido)phenylisopropylidene-4″′-phenoxy] were synthesized. The structures of the monomers were characterized by FT-IR and 1H-NMR spectroscopy. A series of novel poly(amide-imide)s were prepared from this two diacids and aromatic diamines through phosphorylation reaction. The PAIs were characterized by FT-IR, 1H-NMR, XRD, TGA, and DSC, solution viscosity, solubility test and electrical properties. Poly(amide-imide)s showed excellent solubility due to the presence of flexible groups and isopropylidene unit in the polymer backbone. They also exhibited good thermal stability and the temperatures at which 10% weight loss occurred in the range 385–465 °C. These PAIs found to have a dielectric constant in the range 3.25–4.20 at 10 kHz and have excellent electrical insulation character and can be used as insulation materials for electrical items operating at elevated temperatures.
39 citations
TL;DR: In this article, triptycene-containing polyamides were prepared from 1,4-bis(4-carboxyphenoxy)triptycene with aromatic diamines or from 1 4-bis (4-aminophenoxy) triptycan with aromatic dicarboxylic acids via the phosphorylation polyamidation reaction.
Abstract: New triptycene-containing polyamides were prepared from 1,4-bis(4-carboxyphenoxy)triptycene with aromatic diamines or from 1,4-bis(4-aminophenoxy)triptycene with aromatic dicarboxylic acids via the phosphorylation polyamidation reaction. These polyamides were essentially amorphous and showed a significantly increased solubility as compared with their analogs without the triptycene units. All the polyamides could be solution-cast into flexible and tough films. They also showed good thermal stability with glass transition temperatures of 252–295 °C and 10 % weight loss temperatures higher than 540 °C. These polyamides are considered to be promising processable high-temperature polymeric materials.
32 citations
TL;DR: In this paper, an unsymmetrical diamine monomer 4-(2-(4-(4-aminophenoxy)phenyl)propan-2-yl)benzenamine (APPBA) containing C(CH3) groups was synthesized from 2-(4aminophenyl)-2-( 4-hydroxyphenyl)propane and 4-nitrofluorobenzene by the nucleophilic substitution reaction followed by catalytic reduction.
Abstract: A novel unsymmetrical diamine monomer 4-(2-(4-(4-aminophenoxy)phenyl)propan-2-yl)benzenamine (APPBA) containing –O– and –C(CH3)– groups was synthesized from 2-(4-aminophenyl)-2-(4-hydroxyphenyl)propane and 4-nitrofluorobenzene by the nucleophilic substitution reaction followed by catalytic reduction. Polycondensation of this diamine with aromatic dianhydrides through thermal solution imidization techniques afford a series of novel processable polyimides (PI). The structure of the monomer and polyimides were confirmed by FT-IR and 1H-NMR. The polyimides were characterized by XRD, TGA, DSC, electrical property, solution viscosity and solubility test. These polyimides had inherent viscosities in the range 0.48–0.61 dL/g. The X-ray diffraction measurements indicated that all these polyimides were amorphous. The polyimides exhibited excellent solubility in most of the organic solvents. The glass transition temperature (Tg) was observed in the range 242–282 °C. The polyimides displayed good thermal stability and the temperatures at which 10 % weight loss occurred in the range 475–504 °C. The dielectric constant of PIs was in the range of 2.82–3.55.
22 citations
TL;DR: A novel unsymmetrical monomer 5-(4-aminophenoxy)naphthalene-1-amine was prepared from 5-amino1-naphthol and 4-nitrofluorobenzene by the nucleophilic substitution reaction followed by reduction using ‘Sn’ and HCl as mentioned in this paper.
Abstract: A novel unsymmetrical monomer 5-(4-aminophenoxy)naphthalene-1-amine was prepared from 5-amino1-naphthol and 4-nitrofluorobenzene by the nucleophilic substitution reaction followed by reduction using ‘Sn’ and HCl. The structure of the monomer was confirmed by FT-IR and 1H-NMR. A series of aromatic polyimides were successfully prepared from this diamine and aromatic dianhydrides through high temperature solution imidization technique. The polyimides were fully characterized by viscosity measurements, solubility test, FT-IR and 1H-NMR spectroscopy, X-ray diffraction, differential scanning calorimetry, and thermogravimetry. The X-ray diffraction patterns indicated that all these polyimides were amorphous. The polyimides exhibited good solubility in organic solvents. The glass transition temperature values were observed in the temperature range 210–287 °C. Thermogravimetric analysis indicated that 10% weight loss occurred in the temperature range 385–463 °C.
14 citations
References
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TL;DR: Most organic polymeric materials melt below 200 °C and most of them begin to degrade rapidly at temperatures only slightly above 200°G. Thermally stable polymers are those which will withstand much higher temperatures without loss of strength or change of structure as mentioned in this paper.
Abstract: Most organic polymeric materials melt below 200 °C and most of them begin to degrade rapidly at temperatures only slightly above 200°G. Thermally stable polymers are generally considered to be those which will withstand much higher temperatures without loss of strength or change of structure. In general we expect these materials to withstand at least 300°C in air and up to 500°C or higher in inert atmospheres. Polymers which show these properties are usually highly aromatic in structure, often with heterocyclic units, high melting, sometimes infusible and usually with low solubility in all solvents. This makes their fabrication very difficult and as a consequence limits their usefulness.
587 citations
TL;DR: In this article, a poly-p-benzamide of high molecular weight (ηinh = ∼ in H2SO4) was obtained by direct polycondensation reaction of p-aminobenzoic acid (p-ABA) by means of diphenyl and triaryl phosphites in N-methylpyrrolidone (NMP)-pyridine solution containing lithium and calcium chlorides.
Abstract: Poly-p-benzamide of high molecular weight (ηinh = ∼ in H2SO4) was obtained by the direct polycondensation reaction of p-aminobenzoic acid (p-ABA) by means of diphenyl and triaryl phosphites in N-methylpyrrolidone (NMP)-pyridine solution containing lithium and calcium chlorides. Molecular weight of polymer varied with the amount of these salts, showing maximum values at the concentration of about 4 wt-% of LiCl or about 8 wt-% of CaCl2 in the reaction mixture. The reaction temperature at around 80°C gave a polymer of the highest viscosity. The polycondensation reaction was also affected by monomer concentration, solvents, and tertiary amines like pyridine. Similarly, aromatic polyamides with high molecular weight (ηinh values up to 1.34 in H2SO4) were prepared from isophthalic acid and aromatic diamines, whereas terephthalic acid gave only low-viscosity polymers.
529 citations
Book•
01 Aug 1989
TL;DR: Aromatic polyamides aromatic polyhydrazide aromatic polyesters aromatic polyazomethines aromatic polyimides aromatic heterocyclic polymers as mentioned in this paper have been shown to have similar properties.
Abstract: Aromatic polyamides aromatic polyhydrazides aromatic polyesters aromatic polyazomethines aromatic polyimides aromatic heterocyclic polymers.
471 citations
"Synthesis and characterization of a..." refers background in this paper
...Aromatic polyamides are one of the most important classes of high performance polymers because they possess excellent mechanical properties, thermal stability, chemical resistance and low flammability [1–4]....
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