Random multiblock poly(ester amide)s containing poly(L‐lactide) and cycloaliphatic amide segments: Synthesis and biodegradation studies

Novel multiblock poly(ester amide)s containing poly(L ‐lactide) and cycloaliphatic amide segments were synthesized from telechelic oligomer of α,ω‐hydroxyl terminated poly(L ‐lactide), 1,3‐cyclohexylbis(methylamine), and sebacoylchloride by the “two‐step” interfacial polycondensation method. The blocky nature of PEAs was established by FTIR and ¹H NMR spectroscopies. The effect of relative content of ester and amide segments on the crystallization nature of PEAs was investigated by WAXD and DSC analyses. PEAs having lower content of PLLA, PEA 1 and PEA 2, showed a crystallization pattern analogous to polyamides, whereas PEA 3, having higher content of PLLA, showed two crystalline phases characterized by polyester and polyamide segments. Random nature of PEAs was observed from single T_g values. Biodegradation studies using the enzyme lipase from Candida Cylindracea showed higher degradation rate for PEA 3 than that for PEA 1 and PEA 2. FTIR, ¹H NMR, and DSC analyses of the degraded products indicated the involvement of ester linkages in the degradation process. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3250–3260, 2006     

Synthesis and properties of new polyamides derived from 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene and aromatic dicarboxylic acids

The diamine 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene, containing symmetric, bulky di-tert-butyl substituents and a flexible ether unit, was synthesized and used to prepare a series of polyamides by the direct polycondensation with various aromatic dicarboxylic acids in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. All the polymers were obtained in quantitative yields with inherent viscosities of 0.32–1.27 dL g⁻¹. Most of these polyamides, except II _a , II _d , and II _e , showed an amorphous nature and dissolved in polar solvents and less polar solvents. Polyamides derived from 4,4′-sulfonyldibenzoic acid, 4,4′-(hexafluoro-isopropylidene)dibenzoic acid, and 5-nitroisophthalic acid were even soluble in a common organic solvent such as THF. Most polyamide films could be obtained by casting from their N,N-dimethylacetamide (DMAc) solutions. The polyamide films had a tensile strength range of 49–78 MPa, an elongation range at break of 3–5%, and a tensile modulus range of 1.57–2.01 GPa. These polyamides had glass transition temperatures ranging between 253 and 276°C, and 10% mass loss temperatures were recorded in the range 402–466°C in nitrogen atmosphere. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1069–1074, 1998     

Synthesis and characterization of optically active polyamides derived from carbohydrate-based monomers

The synthesis of three new stereoregular AB-type polyamides based on D -ribono-1,4-lactone, L -arabinose, and D -xylose has been carried out by the active ester polycondensation method. These polyamides were characterized by elemental analysis, IR and NMR spectroscopies, and powder X-ray diffraction. They displayed optical activity and had a pronounced affinity to water, although they were not soluble in this solvent. The polyamide obtained from D -ribono-1,4-lactone was highly crystalline and yielded films with spherulitic texture. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3645–3653, 1997     

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     

Novel thermally stable triarylamine‐containing aromatic polyamides bearing anthrylamine chromophores for highly efficient green‐light‐emitting materials

A series of novel polyamides with pendent anthrylamine units were prepared via the direct phosphorylation polycondensation from various diamines and the anthrylamine‐based aromatic dicarboxylic acid, 9‐[N,N‐di(4‐carboxyphenyl)amino]anthracene (4). The aromatic polyamides had useful levels of thermal stability associated with relatively high softening temperatures (T_s) (290–300 °C), 10% weight‐loss temperatures (T_d¹⁰) nearly in excess of 550 °C, and char yields at 800 °C in nitrogen higher than 60%. These aromatic polyamides I exhibited highly photoluminescence quantum yield in NMP solution ranges from 55% for Ia to 74% for Ie due to the introduction of anthrylamine chromophores. Cyclic voltammograms of the polyamide films cast onto an indium‐tin oxide (ITO)‐coated glass substrate exhibited one oxidation and reduction couples (E_onset) around 1.10 and ?1.50 V versus Ag/AgCl in acetonitrile (CH₃CN) and DMF solutions, respectively. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7354–7368, 2008     

New electroactive and electrochromic aromatic polyamides with ether‐linked bis(triphenylamine) units

A new class of electroactive polyamides with ether‐linked bis(triphenylamine) [O(TPA)₂] units were prepared through the direct phosphorylation polycondensation from N,N‐di(4‐aminophenyl)‐N′,N′‐diphenyl‐4,4′‐oxydianiline and aromatic dicarboxylic acids. These polyamides were amorphous with good solubility in many organic solvents, such as NMP and DMAc, and could be solution‐cast into strong and flexible polymer films. Their decomposition temperatures (T_d) at a 10% weight‐loss in nitrogen and air were recorded at 556–568 °C and 537–555 °C, respectively. The glass‐transition temperatures (T_g) of all the polyamides were observed in the range of 218?253 °C by DSC. Cyclic voltammograms of the polyamide films cast onto an indium‐tin oxide (ITO)‐coated glass substrate exhibited two reversible oxidation redox couples at 0.80–0.82 V and 0.96–0.98 V versus Ag/AgCl in an electrolyte containing acetonitrile solution. The polyamide films showed excellent electrochemical and electrochromic stability, with a color change from a colorless or pale yellowish neutral form to green and purple oxidized forms at applied potentials ranging from 0 to 1.2 V. These polymers can also be used to fabricate electrochromic devices, and they showed high coloration efficiency, high redox stability, and fast response time. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 496–510     

Synthesis and characterization of polyamides obtained from tartaric acid and L-lysine

Two sets of AA · BB-type polyamides (PLyTA) were synthesized from natural compounds L-lysine and D- or L-tartaric acid via the active ester polycondensation method. The carboxyl and hydroxyl side groups were orthogonally protected as methyl ester and methyl ether, respectively. Direct reaction of methyl L-lysinate dihydrochloride with bis(pentachlorophenyl) di-O-methyl tartaric acid led to the aregic polyamide ar-PLyTA, whereas isoregic (ir-PLyTA) and syndioregic (sr-PLyTA) polyamides were obtained by polycondensation of specifically designed amide–aminoacid and amide–diamine monomeric precursors, respectively. These polyamides have intrinsic viscosities in the 0.50–0.76 dl g⁻¹ range, display optical activity, and are readily soluble in chloroform. They start to decompose well above 200 °C and display glass-transition temperatures at 100–105 °C. DSC and X-ray diffraction results indicated that these polyamides are not crystalline but they seem to adopt a partially ordered phase. No differences in properties other than optical rotation were observed between PLyTA made of D- and L-tartaric acid.     

Structure and properties of poly(2,5-dimethylterephthalamides)

Six methyl-substituted wholly aromatic polyamides were synthesized from the reaction of 2,5-dimethylterephthaloyl chloride with p-phenylenediamine, its 2,5-dimethyl and 2-methyl derivatives, m-phenylenediamine, or its 2-methyl and 4-methyl derivatives by solution polycondensation at low temperature. The x-ray diffraction diagrams of the polyamides obtained exhibit crystal patterns. Density values range from 1.26 to 1.37 g/cm³. NMR spectra determined in concentrated H₂SO₄ solution are reported. Poly(2,5-dimethylterephthalamides) have lower thermal stability than the corresponding polyterephthalamides. The increase in solubility of polyamide by the introduction of the 2,5-dimethylterephthaloyl linkage is accompanied by a decrease in thermal stability. The effect of methyl substituents on thermal properties and solubility is discussed in terms of the packing of polymeric molecules and the extent of hydrogen bonding of the amide groups.     

Synthesis and liquid crystal properties of bipyridine-containing aromatic polyamides

A series of novel aromatic polyamides containing 2,2′-bipyridine moiety were synthesized by polycondensation of 2,2′-bipyridine-5,5′-dicarboxylic acid ( 2 ) with various aromatic diamines in hexamethylphosphoramide (HMPA) containing lithium chloride. The resulting polyamide solutions in 98% sulfuric acid and in HMPA-LiCl exhibited lyotropic liquid crystal phases. The phase transition behaviors were studied by polarizing microscopy and X-ray diffraction. The polyamides also formed metal complexes with cis-dichlorobis(bipyridine)ruthenium dihydrate [cis-Ru(bpy)₂Cl₂ · 2H₂O] which was supported by changes in electronic spectra.     

Synthesis and characterization of new soluble polyamides derived from 3,3′,5,5′-tetramethyl-2,2-bis[4-(4-carboxyphenoxy)phenyl]propane

A series of new soluble polyamides having isopropylidene and methyl-substituted arylene ether moieties in the polymer chain were prepared by the direct polycondensation of 3,3′,5,5′-tetramethyl-2,2-bis[4-(4-carboxyphenoxy)phenyl]propane and various diamines in N-methyl-2-pyrrolidinone (NMP) containing CaCl₂ using triphenyl phosphite and pyridine as condensing agents. Polymers were produced with moderate to high inherent viscosities of 0.85–1.47 dL g⁻¹ while the weight-average molecular weight and number-average molecular weight were in the range of 86,700–259,000 and 43,300–119,000, respectively. All the polymers were readily dissolved in polar aprotic solvents such as NMP, N,N-dimethylacetamide, and N,N-dimethylformamide, as well as less polar solvents such as m-cresol and pyridine, and even soluble in tetrahydrofuran. These polymers were solution-cast into transparent, flexible and tough films. All of the polymers were amorphous and the polyamide films had a tensile strength range of 82–122 MPa, an elongation at break range of 6–18%, and a tensile modulus range of 2.0–2.8 GPa. These polyamides had glass transition temperatures between 233–260°C and 10% weight loss temperatures in the range of 450–489 and 459–493°C in nitrogen and air atmosphere, respectively. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1997–2003, 1999     

Synthesis and properties of new soluble N-phenyl–substituted aromatic-aliphatic and all aromatic polyamides derived from 4,4′-dianilinobiphenyl

New N-phenylated aromatic-aliphatic and all aromatic polyamides were prepared by the high-temperature solution polycondensation of 4,4′-dianilinobiphenyl with both aliphatic (methylene chain lengths of 6–11) and aromatic dicarboxylic acid chlorides. All of the aromatic-aliphatic polyamides and the wholly aromatic polyamides exhibited an amorphous nature and good solubility in amide-type and chlorinated hydrocarbon solvents, except for those aromatic polyamides containing p-oriented phenylene or biphenylylene linkages in the backbone; the latter were crystalline and insoluble in organic solvents except m-cresol. The N-phenylated aromatic-aliphatic polyamides and aromatic polyamides had glass transition temperatures in the range of 79–116°C and 207–255°C, respectively, and all the polymers were thermally stable with decomposition temperatures above 400°C in air. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2193–2200, 1998     

Synthesis and properties of polyamides derived from 1, 4-bis(4-aminophenoxy)-2-tert-butylbenzene

1, 4-Bis(4-aminophenoxy)-2-tert-butylbenzene was synthesized and used as a monomer to prepare a series of polyamides by the direct polycondensation with various aromatic dicarboxylic acids in N-methyl-2-pyrrolidone using triphenyl phosphite and pyridine as condensing agents. All the polymers were obtained in quantitative yields with inherent viscosities of 0.75–1.75 dL g⁻¹. All the polyamides showed amorphous nature and most of them were soluble in polar solvents. Polyamides derived from 4, 4'-sulfonyldibenzoic acid and 4, 4'-hexafluoroisopropylidenedibenzoic acid were even soluble in common organic solvent such as THF. All polyamide films could be obtained by casting from their DMAc or NMP solutions. The polyamide films had a tensile strength range of 35–84 MPa, an elongation range at break of 3–7%, and a tensile modulus range of 1.2–2.5 GPa. These polyamides had glass transition temperatures between 203–268°C and 10% mass loss temperatures were recorded in the range of 456–472°C in nitrogen and 453–470°C in air atmosphere.     

Synthesis and properties of polyamides with [60]fullerene in the main chain

A novel series of polyamides having [60]fullerene moieties in the main chain were synthesized by a direct polycondensation of [60]fullerenobis(acetic acid) or [60]fullerenobis(acetic acid)/isophthalic acid mixture with a diamine in the presence of triphenyl phosphite and pyridine. Various properties of the polyamides were characterized by means of IR, GPC, TGA, DSC, UV–visible, and photoluminescence. The molecular weight M_w of the [60]fullerene-containing polyamides was observed in the range from about 300,000 to 3,000; upon the changing of the ratio of [60]fullerenobis(acetic acid)/isophthalic acid in the starting mixture, the resulting M_w decreased with increasing the ratio. Most of the thermal and optical properties gradually changed as the ratio changed; the major optical absorption band in visible range exhibited a significant tailing, which shifted toward a longer wavelength, while the photoluminescence spectrum red-shifted with increasing [60]fullerene content. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3139–3146, 1998     

High α transitions of new polyamides based on diamantane

A series of new polyamides were synthesized by direct polycondensation of the 1,6-bis(4-aminophenyl)diamantane with various dicarboxylic acids. The soluble polyamides had high inherent viscosities, ranging from 0.73 to 1.21 dL/g. Polyamides derived from 5-tert-butylisophthalic acid and (±)-1,3-cyclohexanedicarboxylic acid were soluble in N-methyl-2-pyrrolidone (NMP) and pyridine. When NMP and N-dimethylacetamide (DMAc) were added with 3% (w/v) LiCl, the solubilities of polyamides derived from 4,4′-oxybis(benzoic acid) and cis-1,4-cyclohexanedicarboxylic acid were markedly enhanced. Polyamides had tensile strengths of up to 87.8 MPa, elongation to breakage values of up to 19.3%, and initial moduli of up to 2.1 GPa. Dynamic mechanical analysis (DMA) reveals that the polyamides have three relaxations. Their α relaxations occurred at high temperatures, ranging from 380 to 462°C. Three of polyamides exhibited good retention of storage modulus (above 10⁸ Pa) at a temperature exceeding 410°C. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1257–1263, 1998     

Synthesis and characterization of aromatic polymers derived from 5‐perfluoroalkylisophthalic acid

A series of polyisophthalamides and polyisophthalates having perfluorinated side chains were prepared from 5‐perfluoroalkylisophthaloyl dichlorides. The aromatic polyamides and polyarylates synthesized by conventional low temperature solution polycondensation and interfacial polycondensation, respectively, had inherent viscosities of 0.19 to 1.28 dL g⁻¹ in yields of 65 to 100%. Solubilies of the resulting polymers were improved by incorporating nonafluorobutyl groups but not improved by incorporating heptadecafluorooctyl groups. Although the effect on the glass transition temperature (T_g) of incorporating perfluoroalkyl groups into the aromatic polyamides or polyarylate backbone is great, the incorporation maintained the thermal stability of the polymers. In spite of the rigid nature of perfluoroalkyl groups, T_gs were decreased by incorporating perfluoroalkyl groups. The value of the contact angle of water on the aromatic polyamides films gradually increased with incorporation of the perfluoroalkyl groups. On the other hand, the value of the contact angle remarkably increased when perfluoroalkyl groups were incorporated into polyarylates. The Owens γs were also calculated for some aromatic polyamides by measuring contact angles of diiodomethane on the polymer films. The γs were estimated at 23‐37 mN m⁻¹ and about 10% of them were contributed by hydrogen bonding. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1135–1141, 1999     

Preparation and properties of polyhedral oligosilsequioxane tethered aromatic polyamide nanocomposites through Michael addition between maleimide‐containing polyamides and an amino‐functionalized polyhedral oligosilsequioxane

Polyhedral oligosilsequioxane (POSS) tethered aromatic polyamide nanocomposites with various POSS fractions were prepared through Michael addition between maleimide‐containing polyamides and amino‐functionalized POSS. The chemical structures of the polyamide–POSS nanocomposites were characterized with Fourier transform infrared and ¹H NMR. The polyamide–POSS nanocomposites exhibited good homogeneity in scanning electron microscopy and transmission electron microscopy observations. POSS modification increased the storage modulus and Young's modulus of the polyamides, slightly decreased their glass‐transition temperatures from 312 to 305 °C, and significantly lowered their dielectric constants from 4.45 to 3.35. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4632–4643, 2006     

Preparation of polyamides derived from 1,6-diamantane dicarboxylic chloride by solution polycondensation and interfacial polycondensation

1,6-Diamantane dicarboxvlic acyl chloride ( I ) was used as a monomer with various aromatic diamines to synthesize polyamides by interfacial polycondensation and solution polycon-densation. The polyamides prepared by interfacial polycondensation had inherent viscosities between 0.38 and 0.15 dL/g. The polyamides prepared by solution polycondensation had inherent viscosities between 0.62 and 0.25 dL/g. The polyamides IIIa prepared by solution polycondensation showed the main melting transition at 380°C by dynamic mechanical analysis. In addition, it was quite temperature-stable and maintained good mechanical properties (G′?10⁸ Pa) up to high temperatures close to the main transition well above 350°C. The polyamide IIIA had a tensile strength of 35 MPa, elongations to break of 10%, and initial modulus of 0.8 GPa. Some of the polyamides were soluble in NMP, DMAc, and DMSO, depending on soft segment moiety of diamine ( II ). The polyamides prepared by interfacial polycondensation have a greater tendency to form crystal than those prepared by solution polycondensation, as evidenced by x-ray diffraction studies. These polyamides had glass transition temperatures in the 270–300°C range, and 5% weight loss temperatures up to 435°C in nitrogen. © 1995 John Wiley & Sons, Inc.     

Synthesis and characterization of new organosoluble polyamides derived from bis[4‐(4‐carboxyphenoxy) phenyl]diphenylmethane

A new dicarboxylic acid containing a diphenylmethylene linkage, bis[4‐(4‐carboxyphenoxy)phenyl]diphenylmethane (BCAPD), was prepared from bis(4‐hydroxphenyl)diphenylmethane and p‐fluorobenzonitrile via an aromatic nucleophilic substitution reaction followed by hydrolysis. A series of novel polyamides were prepared by the direct polycondensation of BCAPD and various aromatic diamines. The polymers were produced with moderate to high inherent viscosities of 0.80–0.85 dL g^?1. Nearly all the polymers were readily soluble in polar solvents such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, N,N‐dimethylformamide, and dimethyl sulfoxide, in less polar solvents such as pyridine and cyclohexanone, and in tetrahydrofuran. All the polymers were amorphous, and the polyamide films had a tensile strength and a tensile modulus greater than 80 MPa and 2.0 GPa, respectively. These polyamides had glass‐transition temperatures between 249 and 274 °C, and their temperatures at a 10% weight loss were 477–538 and 483–540 °C in nitrogen and air atmospheres, respectively. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1156–1161, 2001     

Dendritic aromatic polyamides and polyimides

The syntheses and properties of dendritic and hyperbranched aromatic polyamides and polyimides are reviewed. In addition to conventional stepwise reactions for dendrimer synthesis, an orthogonal/double‐stage convergent approach and dendrimer syntheses with unprotected building blocks are described as new synthetic strategies for dendritic polyamides. Hyperbranched polyamides and polyimides composed of various repeating units are presented. Besides the self‐polycondensation of AB₂‐type monomers, new polymerization systems with AB₄, AB₈, A₂ + B₃, and A₂ + BB′₂ monomers have been developed for hyperbranched polyamides and polyimides. The copolymerization of AB₂ and AB monomers is discussed separately with respect to the effects of branching units on the properties. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1293–1309, 2004     

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.