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1.
4,4′‐Bis(4‐chloroformylphenylthio)benzene was synthesized in two steps and was reacted with diamine‐containing thioether and amide units to prepare a polyamide containing high contents of thioether groups. The intrinsic viscosities of the polyamides were 0.76–0.87 dL g?1. These polyamides had excellent thermal properties, with glass transition temperatures of 234.8–269 °C and initial degradation temperatures of 461–469.7 °C. They showed improved solubility in polar aprotic solvents and could form moderate strength films with a tensile strength of 75.2–111.6 MPa and storage modulus of 1.0–1.3 GPa (at 220 °C). These polymer films also had good optical properties, including an optical transmittance of the aromatic polyamide film at 450 nm that was higher than 90%. Additionally, the high quantity of thioether units provided the polymers with high refractive indices of 1.700–1.704 and low birefringences of 0.007–0.008. Copyright © 2012 Society of Chemical Industry  相似文献   

2.
In order to obtain polyamides with enhanced solubility and processability, as well as good mechanical and thermal properties, several novel polyamides containing sulfone‐ether linkages and xanthene cardo groups based on a new diamine monomer, 9,9‐bis[4‐(4‐aminophenoxy)phenyl]xanthene (BAPX), were investigated. The BAPX monomer was synthesized via a two‐step process consisting of an aromatic nucleophilic substitution reaction of readily available 4‐chloronitrobenzene with 9,9‐bis(4‐hydroxyphenyl)xanthene in the presence of potassium carbonate in N,N‐dimethylformamide, followed by catalytic reduction with hydrazine and Pd/C. Four novel aromatic polyamides containing sulfone‐ether linkages and xanthene cardo groups with inherent viscosities between 0.98 and 1.22 dL g?1 were prepared by low‐temperature polycondensation of BAPX with 4,4′‐sulfonyldibenzoyl chloride, 4,4′‐[sulfonyl‐bis(4‐phenyleneoxy)]dibenzoyl chloride, 3,3′‐[sulfonyl‐bis(4‐phenyleneoxy)]dibenzoyl chloride and 4,4′‐[sulfonyl‐bis(2,6‐dimethyl‐1,4‐phenyleneoxy)]dibenzoyl chloride in N,N‐dimethylacetamide (DMAc) solution containing pyridine. All these new polyamides were amorphous and readily soluble in various polar solvents such as DMAc and N‐methylpyrrolidone. These polymers showed relatively high glass transition temperatures in the range 238–298 °C, almost no weight loss up to 450 °C in air or nitrogen atmosphere, decomposition temperatures at 10% weight loss ranging from 472 to 523 °C and 465 to 512 °C in nitrogen and air, respectively, and char yields at 800 °C in nitrogen higher than 50 wt%. Transparent, flexible and tough films of these polymers cast from DMAc solution exhibited tensile strengths ranging from 78 to 87 MPa, elongations at break from 9 to 13% and initial moduli from 1.7 to 2.2 GPa. Primary characterization of these novel polyamides shows that they might serve as new candidates for processable high‐performance polymeric materials. Copyright © 2010 Society of Chemical Industry  相似文献   

3.
A novel diamine monomer having pendant 4‐(quinolin‐8‐yloxy) aniline group was successfully synthesized via aromatic substitution reaction of 8‐quinolinol with p‐fluoronitrobenzene followed by Pd/C catalyzed hydrazine reduction, amidation reaction between 4‐(quinolin‐8‐yloxy) aniline and 3,5‐dinitrobenzoylcholoride followed by Pd/C catalyzed hydrazine reduction. The diamine monomer was fully characterized by using FTIR, 1H‐NMR, 13C‐NMR, and elemental analysis. The diamine monomer was polymerized with various aromatic and aliphatic dicarboxylic acids to obtain the corresponding polyamides. The polyamides had inherent viscosity in the range of 0.30–0.41 dL/g and exhibited excellent solubility in the polar aprotic solvents such as DMAc, NMP, N,N‐dimethylformamide, Pyridine, and DMSO. The glass transition temperatures (Tg) of the polymers are high (up to 313°C) and the decomposition temperatures (Ti) range between 200 and 370°C, depending on the diacids residue in the polymers backbone. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

4.
Three diamine monomers containing pyridine groups were prepared via the modified Chichibabin reaction of aromatic aldehydes with 4′-nitroacetophenone, followed by reduction with hydrazine hydrate in the presence of Pd/C. Novel aromatic polyamides containing 4-aryl-2,6-diphenylpyridine moieties and pendant fluorinated phenoxy groups were synthesized from these diamines and two fluorinated isophthaloyl dichlorides by the low temperature solution polycondensation in N,N-dimethylacetamide (DMAc). All the polymers are amorphous and readily soluble in strong polar organic solvents such as DMAc, N-methyl-2-pyrrolidinone (NMP), N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) at room temperature. The resulting polymers showed glass transition temperatures between 270 and 314 °C and 5 % weight loss temperatures ranging from 442 °C to 475 °C, and char yields at 800 °C higher than 53 % in nitrogen. These polyamides could be cast into transparent, flexible and strong films from DMAc solution with tensile strengths of 72.5–87.3 MPa, tensile moduli of 2.35–2.87 GPa, and elongations at break of 5.3–9.5 %. The polyamide films exhibited low dielectric constants of 3.21–3.54 (1 MHz), low water uptakes in the range of 1.17–1.38 %, and high transparency with an ultraviolet-visible absorption cut-off wavelength in the 380–391 nm range.  相似文献   

5.
A new aromatic diamine, 2,3‐bis(4‐(4‐amino‐2‐(trifluoromethyl) phenoxy)phenyl)naphtho[2,3‐f]quinoxaline‐7,12‐dione, was synthesized and fully characterized by using FTIR, 1H and 13C NMR, DEPT technique, and elemental analysis. A series of novel fluorescent anthraquinone‐quinoxaline containing polyamides (PAs) with inherent viscosities of 0.39–0.62 dL/g was prepared by direct polycondensation of the diamine with various dicarboxylic acids. These PAs were readily soluble in many polar aprotic organic solvents and could be solution‐cast into tough and flexible films. The PAs exhibited glass transition temperatures (Tg)s between 230 and 323°C, and 10% weight loss temperatures in the range of 362–433°C in N2. All of the PAs have fluorescence emission in solution and in solid state with maxima around 452–510 nm and with the quantum yields in the range of 6–17%. Also, cyclic voltammetry (CV) method was used to study the electrochemical oxidation behavior of these polymers at the surface of a modified multiwalled carbon nanotube (MWCNT)s glassy electrode. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

6.
Tetraphenylthiophene diamine (TPTDA) was prepared through a modified three‐step route to achieve an improved overall yield. TPTDA reacted with succinic, adipic, suberic, sebasic, and fumaric acids via the Yamazaki phosphorylation method to yield novel partially aromatic polyamides (TPT series). A counterpart polyamide series based on p‐phenylene diamine (Ph series) was also synthesized under the same conditions. All of the polymers were characterized by means of spectrochemical (Fourier transform infrared spectroscopy, 1H‐nuclear magnetic resonance (NMR), and 13C‐NMR) and thermal (differential scanning calorimetry and thermogravimetric) methods of analysis. Solubility of TPT polyamides was clearly improved due to the presence of the bulky aromatic diamine as well as flexible CH2—CH2 segments. The highly phenylated thiophene diamine moiety was recognized to improve thermal stability of the TPT polyamides in comparison with Ph polyamides (integral procedural decomposition temperature (IPDT) 480–517°C against 454–485°C). A favorable balance was recognized in regard to solubility, thermostability, and melting temperature in the TPT polyamides, especially TPT4 and TPT6. Therefore, they may be considered good candidates for processable polymers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1144–1153, 2000  相似文献   

7.
A new diamine 5,5′‐bis[4‐(4‐aminophenoxy)phenyl]‐hexahydro‐4,7‐methanoindan ( 3 ) was prepared through the nucleophilic displacement of 5,5′‐bis(4‐hydroxylphenyl)‐hexahydro‐4,7‐methanoindan ( 1 ) with p‐halonitrobenzene in the presence of K2CO3 in N,N‐dimethylformamide (DMF), followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of new polyamides were synthesized by the direct polycondensation of diamine 3 with various aromatic dicarboxylic acids. The polymers were obtained in quantitative yields with inherent viscosities of 0.76–1.02 dl g−1. All the polymers were soluble in aprotic dipolar solvents such as N,N‐dimethylacetamide (DMAc) and N‐methyl‐2‐pyrrolidone (NMP), and could be solution cast into transparent, flexible and tough films. The glass transition temperatures of the polyamides were in the range 245–282 °C; their 10% weight loss temperatures were above 468 °C in nitrogen and above 465 °C in air. © 2000 Society of Chemical Industry  相似文献   

8.
Seven polyamides containing s-triazine rings in the main chain were synthesized by high temperature polycondensation of 2-(β-naphthylamino)-4,6-bis(naphthoxy-3-carbonyl chloride)-s-triazine [NANCCT] with various aromatic diamines such as 4,4′-diaminodiphenyl [DADP], 4,4′-diaminodiphenylamide [DADPA], 4,4′-diaminodiphenylsulphone [DADPS], 4,4′-diaminodiphenylsulphonamide [DADPSA], 4,4′-diaminodiphenyl methane [DADPM], 2,4-diamino toluene [DAT] and p-phenylene diamine [PPDA]. All the polyamides were characterized by solubility tests, density measurements, viscosity measurements, IR spectra, NMR spectra, and thermogravimetric analysis. The polyamides had inherent viscosities in the range 0.88–1.16 g/dL in N,N′-dimethyl formamide at room temperature (30°C). All the polyamides showed good thermal stability at high temperatures and most of them were soluble readily at room temperature in polar solvents.  相似文献   

9.
Two kinds of monomers containing thioether units 4,6‐bis(4‐chloroformylphenylthio)pyrimidine (BPPM‐DC) and 3,6‐bis(4‐chloroformylphenylthio)pyridazine (BPPD‐DC) were synthesized by two steps and were reacted with diamine‐containing thioether (?S–) and sulfone units to prepare a kind of polyamide containing heterocycles and high contents of thioether groups. These polyamides had good optical properties, including an optical transmittance of the aromatic polyamide film at 450 nm that was higher than 87%. Additionally, the pyridazine, pyrimidine and the large quantity of thioether units provided the polymers with high refractive indices of 1.722–1.732 and low birefringences of 0.004–0.006. These polyamides were also found to have good thermal properties. They showed improved solubility in polar aprotic solvents and could form tough films with a tensile strength of 79.2–112.3 MPa and a storage modulus of 1.4–2.4 GPa (at 200 °C).© 2013 Society of Chemical Industry  相似文献   

10.
A series of aromatic polyamides containing 5‐(4‐acetoxy‐benzamido) pendent groups have been synthesized and their properties have been characterized and compared with those of related polyamides. The polyamides have weight‐ and number‐average molecular weights in the range of 36,680–65,700 and 12,685–35,490, respectively, and polydispersities in the range of 1.82–3.66. These polymers show good thermal stability comparable to traditional aromatic polyisophthalamides, with initial decomposition temperature between 270–320°C and glass transition temperature in the range of 230–270°C. Compared with related polyisophthalamides without any pendent groups, the present polymers show better solubility in certain solvents such as N‐methylpyrrolidinone and dimethylacetamide and can be cast from solutions into thin transparent flexible films having dielectric constants in the range of 3.42–4.27. The polymer films display remarkable hydrophilicity, which makes them potential candidates for use as advanced materials in humidity sensors. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 650–657, 2001  相似文献   

11.
A new quinoxaline moiety containing aromatic diamine; 2,3-bis[4-(4-aminophenoxy)phenyl]quinoxaline (APQ) was synthesized starting from 4-methoxybenzaldehyde and was characterized by IR, 1H, 13C NMR and Mass spectrometry. Five new polyamides were synthesized by polycondensation of various aliphatic diacid / aromatic diacids namely, azelaic acid, bis(4-carboxyphenyl)dimethylsilane, 4,4′-oxybis(benzoicacid), isophthalic acid and terephthalic acid with APQ by Yamazaki’s phosphorylation method using triphenyl phosphite as condensing agent. The polyamides were characterized by IR spectroscopy, solubility tests, inherent viscosity, X-ray diffraction technique, differential scanning colorimetry and thermogravimetric analysis. The polyamides had inherent viscosities in the range 0.39–0.45 dL/g in N, N-dimethylacetamide at 30?±?0.1?°C. The polyamides were soluble in polar aprotic solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone. X-Ray diffraction studies showed that polyamides were amorphous in nature. The polyamides showed glass transition temperatures in the range 104–205?°C, according to differential scanning calorimetry. Thermogravimetric analysis exhibited initial decomposition temperatures above 348?°C; indicating that these polyamides possessed excellent thermal stability.  相似文献   

12.
BACKGROUND: Wholly aromatic polyamides (aramids) are high‐performance polymeric materials with outstanding heat resistance and excellent chemical stabilities due to chain stiffness and intermolecular hydrogen bonding of amide groups. Synthesis of structurally well‐designed monomers is an effective strategy to prepare modified forms of these aramids to overcome lack of organo‐solubility and processability limitations. RESULTS: A novel class of wholly aromatic polyamides was prepared from a new diamine, namely 2,2′‐bis(p‐phenoxyphenyl)‐4,4′‐diaminodiphenyl ether (PPAPE), and two simple aromatic dicarboxylic acids. Two reference polyamides were also prepared by reacting 4,4′‐diaminodiphenyl ether with the same comonomers under similar conditions. M?w and M?n of the resultant polymers were 8.0 × 104 and 5.5 × 104 g mol?1, respectively. Polymers resulting from PPAPE exhibited a nearly amorphous nature. These polyamides exhibited excellent organo‐solubility in a variety of polar solvents and possessed glass transition temperatures up to 200 °C. The 10% weight loss temperatures of these polymers were found to be up to 500 °C under a nitrogen atmosphere. The polymers obtained from PPAPE could be cast into transparent and flexible films from N,N‐dimethylacetamide solution. CONCLUSION: The results obtained show that the new PPAPE diamine can be considered as a good monomer to enhance the processability of its resultant aromatic polyamides while maintaining their high thermal stability. The observed characteristics of the polyamides obtained make them promising high‐performance polymeric materials. Copyright © 2009 Society of Chemical Industry  相似文献   

13.
A series of new aromatic polyamides containing cinnamide pendent units were prepared from 2′‐(cinnamide)ethyl‐3,5‐diaminobenzoate and various aromatic dicarboxylic acids by the direct polycondensation reaction, with triphenyl phosphite and pyridine as condensing agents. The polyamides were characterized by 1H NMR, IR, and UV spectroscopy, and gel permeation chromatography. Their thermal stability was studied by thermogravimetric analysis in air, and differential scanning calorimetry. These polymers were readily soluble in polar aprotic solvents and can be cast from their solutions in flexible and tough films. Glass transition temperatures (Tgs) of these polyamides were observed in the range of 225–245°C. Their inherent viscosities varied from 0.77 to 1.12 dL/g that corresponded to weight–average and number–average molecular weights of 39,000–72,700 and 18,800–29,000, respectively. These polymers can be photochemically crosslinked. The photochemical aspects were revealed by means of UV–vis and IR analyses onto thin films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2013–2020, 2007  相似文献   

14.
A novel monomer diacid, 6,6′‐methylenebis(2‐oxo‐2H‐chromene‐3‐carboxylic acid), was synthesized and used in a direct polycondensation reaction with various aromatic diamines in N‐methyl‐2‐pyrrolidone solution containing dissolved LiCl and CaCl2, using triphenyl phosphite and pyridine as condensing agents to give a series of novel heteroaromatic polyamides containing photosensitive coumarin groups in the main chain. Polyamide properties were investigated by DSC, TGA, GPC, wide‐angle X‐ray scattering, viscosity, and solubility measurements. The copolymers were soluble in aprotic polar solvents, and their inherent viscosities varied between 0.49 and 0.78 dL g?1. The weight‐average and number‐average molecular weights, measured by gel permeation chromatography, were 27,500–43,900 g mol?1 and 46,500–66,300 g mol?1, respectively, and polydispersities in the range of 1.48–1.69. The aromatic polyamides showed glass‐transition temperatures (Tg) ranging from 283 to 329°C and good thermal properties evidenced by no significant weight loss up to 380°C and 10% weight loss recorded above 425°C in air. All the polyamides exhibited an amorphous nature as evidenced by wide‐angle X‐ray diffraction and demonstrated a film forming capability. Water uptake values up to 3.35% were observed at 65% relative humidity. These polymers exhibited strong UV‐vis absorption maxima at 357–369 nm in DMSO solution, and no discernible photoluminescence maxima were detected by exciting with 365 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

15.
The aim of study was to prepare novel polyamides with improved solubility and processability without sacrifice of their thermal and mechanical properties. Polyamides containing ether and sulfone units were obtained via condensation of a special diamine with various diacid chlorides. Poly(ether ether sulfone amide)s were obtained in good inherent viscosities ranging from 0.72 to 0.84 dL/g. All the polyamides were amorphous and readily soluble in polar solvents and swelled in CH2Cl2 and tetrahydrofuran. Flexible films of polymers were obtained by solution casting. Polyamide films exhibited good mechanical and thermal stability including the temperature for 10% weight loss of 449–476 °C.  相似文献   

16.
A series of fluorinated polyamides was prepared directly by low‐temperature polycondensation of a new cardo diacid chloride, 9,9‐bis[4‐(4‐chloroformylphenoxy)phenyl]xanthene (BCPX), with various diamines containing trifluoromethyl substituents in N,N‐dimethylacetamide (DMAc). Almost all polyamides showed excellent solubility in amide‐type solvents such as DMAc and could also be dissolved in pyridine, m‐cresol, and tetrahydrofuran. These polymers had inherent viscosities between 0.77 and 1.31 dL g?1, and their weight‐average molecular weights and number‐average molecular weights were in the range of 69,000–102,000 and 41,000–59,000, respectively. The resulting polymers showed glass transition temperatures between 240–258°C and 10% weight loss temperatures ranging from 484°C to 517°C and 410°C to 456°C in nitrogen and air, respectively, and char yields at 800°C in nitrogen higher than 55%. All polymers were amorphous and could be cast into transparent, light‐colored, and flexible films with tensile strengths of 81–100 MPa, elongations at break of 8–12%, and tensile modulus of 1.6–2.1 GPa. These polymers had low‐dielectric constants of 3.34–3.65 (100 kHz), low‐moisture absorption in the range of 0.76–1.91%, and high transparency with an ultraviolet–visible absorption cut‐off wavelength in the 322–340 nm range. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

17.
A series of six new aromatic polyamides with side oxadiazole rings has been synthesized by polycondensation reaction of aromatic diamines containing pendent substituted oxadiazole groups with a silicon‐containing diacid chloride [namely, bis(p‐chlorocarbonyl‐phenylene)diphenylsilane] or with a fluorine‐containing diacid chloride [namely, hexafluoroisopropylidene‐bis(p‐benzoyl chloride)]. All polymers were easily soluble in amidic solvents, such as N‐methylpyrrolidinone and dimethylformamide, and gave thin transparent films by casting such solutions. Very thin coatings were deposited onto silicon wafers and exhibited smooth, pinhole‐free surfaces in atomic force microscopy investigations. The polymers showed high thermal stability, with decomposition temperature >400°C. Some of them did exhibit a glass transition, in the range 152–276°C, with a reasonable interval between glass transition and decomposition. Four of these polymers showed blue photoluminescence, in the range 460–480 nm, which makes them promising candidates for future use as high‐performance materials in the construction of light‐emitting devices. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 714–721, 2003  相似文献   

18.
Aromatic polyamides containing thioether units were synthesized by interfacial polycondensation of 4,4′‐thiodibenzoyl chloride (or 4,4′‐bis(4‐chloroformylphenylthio)benzene) with aromatic diamines containing a nitrile unit. Their structure was established using 1H NMR and Fourier transform infrared spectroscopy. The inherent viscosities of the polyamides prepared with optimum synthesis conditions were in the range 0.71–0.84 dL g?1. These polyamides showed excellent thermal properties with glass transition temperatures of 210.5–219.6 °C, melting temperatures of 313.8–315.0 °C and initial degradation temperatures of 440–459 °C. They could be processed by melting due to their relatively wide processing window. Their tensile strengths were 71.3–79.1 MPa, water absorption was 0.17–0.22 wt%, and melt flowability was in the range 64.5 to 315.2 Pa s and 68.5 to 422.3 Pa s at different shear rates. At the same time, they were soluble in aprotic solvents such as N‐methyl‐2‐pyrrolidone, dimethylformamide and dimethylsulfoxide. The results suggest that these aromatic polyamides containing thioether units represent a promising type of heat‐resistant and processable engineering plastic. © 2012 Society of Chemical Industry  相似文献   

19.
New fluorine‐containing, triphenylamine‐based diamine and dicarboxylic acid monomers, namely 3,5‐bis(trifluoromethyl)‐4′,4″‐diaminotriphenylamine and 3,5‐bis(trifluoromethyl)‐4′,4″‐dicarboxytriphenylamine, were synthesized and polymerized with commercially available aromatic dicarboxylic acids and diamines, respectively, leading to two series of aromatic polyamides, 5a–h and 7a–e . Most of the polyamides were amorphous and readily soluble in many common organic solvents and could be solution‐cast into transparent, flexible and strong films with good mechanical properties. The polyamides had useful levels of thermal stability associated with high glass transition temperatures of 273–305 °C and 10% weight‐loss temperatures in excess of 500 °C. Cyclic voltammograms of films of polymers 5a–h on indium–tin oxide‐coated glass substrates exhibited reversible oxidation redox couples with E1/2 around 1.15 V versus Ag/AgCl in tetrabutylammonium perchlorate/acetonitrile solution, accompanied by a color change from colorless neutral state to reddish brown oxidized state. The 7 series polymers displayed a higher oxidation potential and less electrochemical stability as compared to the 5 series analogues. © 2017 Society of Chemical Industry  相似文献   

20.
A series of novel aromatic polyamides containing both fluorene or xanthene cardo moieties and fluorinated phenoxy pendant groups were synthesized from two fluorinated isophthaloyl chlorides and four diamines containing cardo groups by the low‐temperature solution polycondensation in N,N‐dimethylacetamide (DMAc). The obtained polymers were characterized by different physicochemical techniques. All the polymers were amorphous and readily soluble in many organic solvents such as DMAc, N‐methyl‐2‐pyrrolidinone, N,N‐dimethylformamide, dimethyl sulfoxide, pyridine, and tetrahydrofuran at room temperature. The new fluorinated polyamides had high thermal stability with the glass transition temperatures of 237–259°C, the temperatures at 5% weight loss of 437–476°C in nitrogen. All the polymers formed transparent, strong, and flexible films with tensile strengths of 70.6–87.5 MPa, tensile moduli of 2.23–2.78 GPa, and elongations at break of 5.8–8.7%. These polyamide films had high optical transparency with an ultraviolet–visible absorption cutoff wavelength of 352–368 nm, low dielectric constants of 3.24–3.45 (1 MHz), and lower water absorptions of 1.06–1.43%. POLYM. ENG. SCI., 57:1234–1241, 2017. © 2017 Society of Plastics Engineers  相似文献   

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