Synthesis and characterization of aromatic polyamides containing S-triazine rings in the main chain

Ten new aromatic polyamides containing s-triazine rings in the main chain were synthesized by the low temperature interfacial polycondensation technique involving the reactions of each of the two s-triazine containing diacylchlorides, viz., 2,4-bis (4-chlorocarbonylphenoxy)-6-methoxy-s-triazine and 2,4-bis(3-chlorocarbonylphenoxy)-6-methoxy-s-triazine, with five aromatic diamines namely, 4,4′-bis(4-aminophenoxy)diphenyl sulfone, 4,4′-bis(3-aminophenoxy)diphenyl sulfone, 2,2-bis[4(4-aminophenoxy) phenyl] propane, 1,4 bis (4-amino-phenoxy) benzene, and 1,3-bis (4-aminophenoxy)benzene. The resulting polyamides were characterized by viscosity measurements, IR and ¹H-NMR spectroscopy, solubility tests, x-ray diffraction, and thermogravimetry. The polyamides had inherent viscosities in the range of 0.16–1.06 dL/g in N,N-dimethylacetamide at 30°C. Most of the s-triazine containing polyamides dissolved readily at room temperature in polar solvents. Except for the polyamide PA-2, the polyamides did not lose weight below 350°C under a nitrogen atmosphere. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1077–1085, 1997     

Synthesis and characterization of organosoluble polyamides from quinoxaline based diamine

<正>Aromatic/aliphatic polyamides were synthesized from a diamine monomer,2,3-bis-p-aminophenylquinoxaline (Ⅳ),based on quinoxaline and various dicarboxylic acids of aliphatic,aromatic and heterocyclic.The diamine and polyamides were characterized by elemental analysis,FTIR and ~1H-NMR.The solubility of the polyamides was affected by the quinoxaline and heterocyclic groups in the polymer chain.They were all soluble in common organic solvents such as dimethylsulfoxide(DMSO),N,N-dimethylformamide(DMF) and N-methylpyrolidone(NMP).The polyamides showed inherent viscosity in the range of 0.25-0.3 dL/g in DMSO at 25℃and good thermal stability with the char yields in the range of 65%-82%at 600℃in nitrogen.     

Processable heat resistant polyamides containing tetraphenyl thiophene having pendant phenyl moiety with heterocyclic quinoxaline unit: Synthesis and characterization

A series of new polyamides containing tetraphenyl thiophene having pendant phenyl moiety with heterocyclic quinoxaline unit were synthesized by using the solution polycondensation method of novel diamine monomer V with isopthaloyl chloride (IPC) and terpthaloyl chloride (TPC) in various mole proportions. These novel polymers were characterized by FT-IR, solubility, inherent viscosity, thermal analysis and X-ray diffraction studies. Inherent viscosities of these polymers were in the range 0.66 to 1.44 dL/g indicating moderate to high molecular weight built-up. These polymers exhibited solubility in various solvents such as DMAc, NMP, pyridine, m-cresol etc. X-ray diffraction pattern of polymers showed that introduction of pendant phenyl moiety would disturb the chain regularity and packing, leading to amorphous nature. Thermal analysis by TGA and DSC showed excellent thermal stability of polymers. The structure -property correlation among these polyamides were studied, in view of these polymer's potential applications as processable high temperature resistance materials.     

Synthesis and characterization of tough polycyclic polyamides containing 4,9-Diamantyl moieties in the main chain

A series of new polyamides were synthesized by direct polycondensation of the 4,9-diamantane dicarboxylic acid ( I ) with various aromatic diamines in N-methyl-2-pyrrolidone (NMP) containing lithium chloride. The polyamides had inherent viscosities of 0.56–1.85 dL/g. Dynamic mechanical analysis revealed the polymers IIIa–IIId to have main melting transitions at 403, 431, 423, and 452°C, respectively. Moreover, these polymers were quite stable at high temperatures and maintained good mechanical properties (G′ = ca. 10⁸ Pa) up to temperatures close to the main transition well above 400°C. Although the polyamides contained rigid 4,9-diamantyl moieties in the main chain, the tensile properties of the polyamides showed toughness. Elongations of polyamides IIIa and IIIb reached 38.3 and 31.7%, respectively, before breaking. A glass transition was not observed. However, polyamide IIIc shows a melting transition with a sharp endothermic peak at 423°C by DSC measurement. Additionally, the introduction of 4,9-diamantyl units into the polyamide backbone resulted in polyamides with high thermal stability and good mechanical properties. © 1996 John Wiley & Sons, Inc.     

Synthesis and characterization of aromatic polyamides containing alkylphthalimido pendent groups

A series of polyisophthalamides containing pendent phthalimido groups and flexible side spacers were prepared from four novel diacids and three commercial aromatic diamines. These polyamides were prepared in high yields and with high molecular weights by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. The weight‐average and number‐average molecular weights, measured by gel permeation chromatography, were 70,000–137,000 and 47,000–86,000 g/mol, respectively. The novel polyamides were amorphous and readily soluble and showed glass‐transition temperatures of 150–240 °C, as measured by differential scanning calorimetry. Thermogravimetric analysis showed that the 10% weight‐loss temperatures in nitrogen were 355–430 °C, a significant improvement in thermal stability having been observed with the increase in the side‐chain length. A theoretical quantum mechanical study was successfully carried out to explain these results. Flexible and tough films, cast from polymer solutions, showed tensile strengths of 50–125 MPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3711–3724, 2002     

Synthesis and characterization of polyamides containing s-triazine rings in the main chain

Polyamides were synthesized from diacids containing a s-triazine ring and two aromatic diamines, namely 4,4′-diaminodiphenyl ether (ODA) and 4,4′-diaminodiphenylmethane (MDA), by direct polycondensation using the phosphorylation reaction. Polymers thus obtained were characterized by viscosity measurement, IR spectroscopy, thermogravimetry, X-ray diffraction, and solubility tests. These polyamides had inherent viscosities in the range of 0.51–0.77 dL/g, and were amorphous in nature. All the polymers were readily soluble in various organic solvents and did not lose weight below 270°C in air.     

Synthesis and characterization of polyamides containing pendant pentadecyl chains

A new aromatic diacid monomer viz., 4-(4′-carboxyphenoxy)-2-pentadecylbenzoic acid was synthesized starting from cardanol and was characterized by FTIR, ¹H- and ¹³C NMR spectroscopy. A series of new aromatic polyamides containing ether linkages and pendant pentadecyl chains was prepared by phosphorylation polycondensation of 4-(4′-carboxyphenoxy)-2-pentadecylbenzoic acid with five commercially available aromatic diamines viz., 1,4-phenylenediamine, 4,4′-oxydianiline, 4,4′-methylenedianiline, 1,3-phenylenediamine, and 4,4′-(hexafluoroisopropylidene)dianiline. Inherent viscosities of the polyamides were in the range 0.45-0.66 dL/g in N,N-dimethylacetamide at 30 ± 0.1 °C. The introduction of ether linkages and pendant pentadecyl chains into polyamides led to an enhanced solubility in N,N-dimethylacetamide and 1-methyl-2-pyrrolidinone at room temperature or upon heating. The polyamides could be solution-cast into tough, flexible and transparent films from their N,N-dimethylacetamide solution. Wide angle X-ray diffraction patterns exhibited broad halo indicating that the polymers were essentially amorphous in nature. X-Ray diffractograms also displayed a diffuse to sharp reflection in the small-angle region (2θ = ∼2-5°) for the polyamides characteristics of formation of loosely to well-developed layered structure arising from packing of flexible pentadecyl chains. The glass transition temperature observed for the polyamides was in range 139-189 °C. The temperature at 10% weight loss (T₁₀), determined by TGA in nitrogen atmosphere, of the polyamides was in the range 425-453 °C indicating their good thermal stability.     

Synthesis,characterization and corrosion inhibitive properties of new thiazole based polyamides containing diarylidenecyclohexanone moiety

The present work aimed to synthesize a new interesting series of thiazole based polyamides containing diarylidenecyclohexanone moiety 5a-5f using low temperature solution polycondensation technique. The new polymers were synthesized by the reaction of thiazole based monomer namely, bis(2-aminothiazol-4-ylbenzylidene)cyclohexanone 3 with different aliphatic and aromatic diacid chlorides using NMP, and in the presence of anhydrous Li Cl as catalyst. Adipoyl, sebacoyl, oxaloyl, terephthaloyl, isophthaloyl dichlorides and biphenyl dicarbonyl dichloride were used as diacid chlorides. The structure of the model compound 4 as well as the new polymers was confirmed by correct elemental and spectral analyses. The thermal properties of those polymers were evaluated by TGA and DTG measurements and correlated to their structural units, beside X-ray diffraction analysis, solubility and viscometry measurements. The inherent viscosities for the synthesized polymers were in the range 0.6–1.03 d L/g. On the other hand the corrosion inhibitive properties of monomer 3 as well as polyamides 5d and 5f as selected examples were carried out on carbon-steel in 0.5 mol/L H2SO4 at 40 °C. The calculated inhibition efficiency(IE%) for polymer 5d was in the range(82 ± 6)% in all selected concentrations. The best value of IE% was obtained at 1 mg/L to reach 98.24% for polymer 5d and at 0.5 mg/L to reach 87.75% for polymer 5f.     

Synthesis and characterization of new polyamides containing adamantyl and diamantyl moieties in the main chain

This work synthesized a series of new polyamides by direct polycondensation of 1,3-bis[4-(4-carboxyphenoxy)phenyl]adamantane ( I ) with various diamines. The diacid I was synthesized from 1,3-bis(4-hydroxyphenyl)adamantane in two steps. Polyamides III were soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), and pyridine. The polyamides had medium inherent viscosities of 0.30–0.55 dL/g and number-average molecular weights (M_n) of 22,000–36,000. The polyamides III _a and III _b had tensile strengths of 59.8 and 77.5 MPa, elongation to breakage values of 5.8 and 7.6%, and initial moduli of 1.9 and 1.8 GPa, respectively. Their glass transition temperatures were found to be 219–295°C by means of differential scanning calorimetry (DSC). Dynamic mechanical analysis (DMA) reveals that the incorporation of rigid and bulky diamantane into polyamides III _a and III _b leads to high glass transition temperatures (T_gs), at 299 and 286°C, respectively. The decomposition temperatures of polyamides III at a 5% weight loss ranged from 388 to 416°C in air and from 408 to 435°C in N₂ atmosphere. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 785–792, 1998     

Synthesis and characterization of Schiff-base-containing polyamides

A series of new Schiff base polyamides（PAs） were synthesized by polycondensation of benzilbisthiosemicarbazone diamine（LH₆） with different commercially available aliphatic and aromatic diacid chlorides. The monomer and all the PAs were characterized by FTIR,¹H-NMR,and elemental analysis.The prepared polyamides showed inherent viscosities in the range of 0.30-0.36 dL/g in DMF at 25℃,indicating their moderate molecular weight.The PAs were completely soluble in aprotic polar solvents such as dimethylformamide（DMF）,N-methylpyrolidone（NMP）, tetrachloroethane（TCE）,dimthylsulfoxide（DMSO） and also in H₂SO₄ and partially soluble in THF,acetone and chloroform at room temperature.Thermal analysis showed that these PAs were practically amorphous and exhibited 10%weight loss above 220℃.     

Synthesis and characterization of processable heat resistant co-poly(ester-amide)s containing cyclopentylidene moiety

New cyclopentylidene ring-containing diamino-diesters, 1,1-bis(3-aminobenzoyloxy phenyl) cyclopentane, was prepared through reaction of cyclopentanone with two moles of phenol to yield 1,1-bis (4-hydroxy phenyl) cyclopentane (BHPP) (I), the resulting diol (I) on reaction with 3-nitrobenzoyl chloride in N,N-dimethyl acetamide (DMAc) and triethyl amine yield 1,1-bis(3-nitrobenzoyloxy phenyl) cyclopentane (II) which on finally reduced by catalytic hydrogenation in presence of 10% Pd/C in DMAc and stirred at room temperature under a 4 kg/cm² hydrogen pressure yields 1,1-bis(3-aminobenzoyloxy phenyl) cyclopentane (III) (m-BABPP). The structure of novel m-diester-diamine was confirmed by FT-IR, ¹H-NMR and ¹³C-NMR. A series of new m-poly (ester-amide)s and co-poly(ester-amide)s were synthesized by using the solution polycondensation method of novel diamine (III) with IPC and TPC in various mole proportion. These novel polymers were characterized by FTIR spectroscopy, solubility, inherent viscosity and thermal analysis and XRD studies. Inherent viscosities of these polymers were in the range 0.30 to 0.46 dL/g indicating moderate molecular weight built-up. These polymers exhibited excellent solubility in various polar aprotic solvents such as NMP, Pyridine. These polymers were partially soluble in DMSO, DMAc, DMF etc.

X-Ray diffraction pattern of polymers showed that introduction of cardo moiety containing ester linkage would disturb the chain regularity and packing, leading to amorphous nature. Thermal analysis by TGA showed excellent thermal stability of polymers. The structure -property correlation among these poly(ester-amide)s were studied, in view of these polymer's potential applications as processable high temperature resistance materials.     

Synthesis,characterization, and comparison of properties of new fluorinated poly(arylene ether)s containing phthalimidine moiety in the main chain

Four new poly(arylene ether)s have been prepared by the reaction of N‐phenyl‐3,3‐bis(4‐hydroxyphenyl)phthalimidine (PA) with four different perfluoroalkylated monomers namely 1,3‐bis(4′‐fluoro‐3′‐trifluoromethyl benzyl) benzene, 4,4′‐bis(4′‐fluoro‐3′‐trifluoromethyl benzyl) biphenyl, 2,6‐bis(4′‐fluoro‐3′‐trifluoromethyl benzyl) pyridine, and 2,5‐bis(4′‐fluoro‐3′‐trifluoromethyl benzyl) thiophene. The poly(arylene ether)s were characterized by different spectroscopic, thermal, mechanical, and electrical techniques. The poly(arylene ether) containing quadriphenyl unit in the main chain showed very high glass transition temperature of 291°C and outstanding thermal stability upto 556°C for 10% weight loss under a 4:1 nitrogen:oxygen mixture. The polymers were soluble in a wide range of organic solvents. Transparent thin films of these polymers exhibited tensile strengths upto 75 MPa and elongation at break upto 32%. The films of these polymers showed low water absorption of 0.26%. Copyright © 2009 John Wiley & Sons, Ltd.     

Optically transparent,organosoluble poly(ether-amide)s bearing triptycene unit; synthesis and characterization

Abstract

Aromatic polyamides are famous high performance polymeric materials for their excellent thermal, mechanical, electrical properties, which now a days became a dominant platform for modern polymer chemistry area. Triptycene unit like structures in polymer directly affects the physiochemical properties of polymer, thus polyamides especially with triptycene unit in their backbone with aryl ether linkage imparts combination of properties such as better solubility, melts processing characteristics, and better thermal stability in contrast with those of polymers without an aryl-ether linkageNew triptycene-containing bis(ether amine), 1,4-bis(4-aminophenoxy), 2, 3-benzotriptycene (4a) was synthesized from nucleophilic displacement reactions of P-fluoronitrobenzene with 1,4-dihydroxytriptycene, followed by reduction, and elucidated by FTIR, ^1?H, ^13?C NMR spectroscopy and HRMS. A series of new polyamides containing pendant triptycene group and flexibilizing ether linkages was synthesized by polycondensation of diamine with commercially available aromatic diacischlorides viz., terephthalylchloride (TPC), isophthalylchloride (IPC) and varying molar mixture of TPC and IPC accordingly. Synthesized Poly(ether-amide)s were found soluble in common organic solvents such as chloroform, dichloromethane, tetrahydrofuran, DMF, DMAc, DMSO also could be cast into excellent transperent thin films. Inherent viscosities of polyamides were in the range 0.44–0.57 dL/g. Polyamides exhibited initial decomposition temperature (T_i), glass transition temperatures (T_g) and temperature at 10% wt loss (t₁₀), which was determined by TGA were noted in the range 212?°C–305?°C, 295?°C –309?°C and 587?°C–631?°C respectively with 24%–54% char yeild at 900?°C under nitrogen atmosphere, indicating its better thermal stability and moderate glass transition temperature.     

Thermally stable and organo-soluble polyamides containing triazine rings and ether linkages in the main chain: Synthesis and characterization

In order to synthesize new polyamide(PA) 5 and copolyamides(Co PA) 7a-7d, a new-type of dicarboxylic acid containing triazine ring was successfully synthesized from 2,4-dichloro-6-methoxy-s-triazine 1 and 4-aminobenzoic acid. New polyamide 5 containing triazine moiety was prepared from 4,4'-(6-methoxy-1,3,5-triazine-2,4-diyl)bis(azanediyl)dibenzoic acid 3 and 4,4′-diaminodiphenylether by direct polycondensation reaction. Then new series thermally stable copolyamides 7a-7d with high solubility in common organic solvents were synthesized from the direct polycondensation reaction of diacid 3 as a first monomer, aliphatic-aromatic diacids 6a-6d as second diacids and 4,4′-diaminodiphenylether. All of the above polymers were fully characterized by 1H-NMR and FTIR spectroscopy, elemental analysis(CHN), inherent viscosity, solubility tests, gel permeation chromatography(GPC), differential scanning calorimetry(DSC) and thermogravimetric analysis(TGA). The resulted Co PAs 7a-7d have shown good inherent viscosities, solubility and thermal properties.     

Synthesis and characterization of novel aromatic polyamides derived from two heterocyclic diamines

Two diamines were synthesized as new aromatic monomers. A series of novel aromatic polyamides (aramids) were also synthesized by direct and indirect polycondensation of these diamines with various aromatic dicarboxylic acids. These aramids have inherent viscosities of 0.43-0.84 dl/g and were obtained in quantitative yield.     

Synthesis and some properties of a polyamide containing trans-2,5-linked tetrahydropyran rings in the main chain

A novel polyamide containing trans-2,5-linked tetrahydropyran rings in the main chain, poly(trans-tetrahydropyran-2,5-diyliminocarbonyl) (trans-polyamide 6 ), was synthesized by the two-stage polycondensation of ethyl or 2,2,2-trifluoroethyl trans-5-aminotetrahydropyran-2-carboxylate ( 5b or 5c ). The polycondensation was carried out first in m-cresol at 180°C. The isolated polymer of a relatively low molecular weight was then allowed to react further in a solid state at different temperatures between 180 and 230°C under vacuum. The trans-polyamide 6 thus obtained was soluble only in protic solvents such as m-cresol, 2,2,2-trifluoroethanol, 1,1,1,3,3,3-hexafluoro-2-isopropanol, and trifluoroacetic acid. The viscosity numbers of 6 were up to 0.46 dL/g in m-cresol at 25°C. DSC and TGA analyses of 6 showed that the thermal decomposition occurred at about 350°C in nitrogen, whereas a rapid weight decrease due to the thermooxidative decomposition started at about 300°C in air. The moisture sorption isotherm was determined on coarsely ground samples of 6 at 25°C and compared with those for the structurally-related polyamides 2 and 4 . © 1993 John Wiley & Sons, Inc.     

Synthesis and characterization of new soluble polyamides containing phthalimide pendent group

A dicarboxylic acid monomer, 5-phthalimidoisophthalic acid, containing a phthalimide pendent group was prepared by the condensation of 5-aminoisophthalic acid and phthalic anhydride in glacial acetic anhydride. The monomer was reacted with various aromatic diamines to produce polyamides using triphenyl phosphite and pyridine as condensing agents. These polyamides were produced with inherent viscosities of 0.64–1.14 dL · g⁻¹. All the polymers, characterized by wide-angle X-ray diffraction, revealed an amorphous nature resulting from the presence of the bulky pendent group. These polyamides exhibited excellent solubility in a variety of solvents such as N- methyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, dimethyl sulfoxide, pyridine, and cyclohexanone. These polyamides showed glass-transition temperatures (T_g's) between 247 and 273 °C (by DSC) and 248 and 337 °C (by a dynamic mechanical analyzer). The thermogravimetric analytic measurement revealed the decomposition temperature at 10% weight-loss temperatures (Td₁₀) ranging from 442 to 530 °C in nitrogen. The polyamides containing phthalimide groups exhibited higher T_g and Td₁₀ values than those having no phthalimide groups. Transparent, tough, and flexible films of these polyamides could be cast from the DMAc solutions. These casting films had tensile strengths ranging from 81 to 126 MPa, elongations at break ranging from 7 to 13%, and tensile moduli ranging from 2.0 to 2.9 GPa. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1557–1563, 2001