Synthesis and characterization of poly(2,5‐furan dicarboxylate)s based on a variety of diols

Novel polyesters from renewable resources based on 2,5‐dicarboxylic acid and several diols were synthesized and characterized using different polycondensation techniques. The aliphatic diols were sufficiently volatile to allow the use of polytransesterifications, which gave high‐molecular weight semicrystalline materials with good thermal stability. In particular, the polyester based on ethylene glycol displayed properties comparable with those of its aromatic counterpart, poly(ethylene terephthalate), namely, the most important industrial polyester. The use of isosorbide gave rise to amorphous polymers with very stiff chains and hence a high glass transition temperature and an enhanced thermal stability. The interfacial polycondensation between the acid dichloride and hydroquinone produced a semicrystalline material with features similar to those of entirely aromatic polyesters, characterized essentially by the absence of melting and poor solubility, both associated with their remarkable chain rigidity. The replacement of hydroquinone with the corresponding benzylic diol was sufficient to provide a more tractable polyester. This study provided ample evidence in favor of the exploitation of furan monomers as renewable alternatives to fossil‐based aromatic homologs. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis and characterization of organo‐soluble polyamides containing triaryl imidazole pendant and ether linkage moieties: thermal,photophysical, and chemiluminescent properties

A new symmetrical diamine monomer containing a triaryl imidazole pendant group was successfully synthesized by the nucleophilic substitution of hydroquinone with the synthesized 2‐(2‐chloro‐5‐nitrophenyl)‐4, 5‐diphenyl‐1H‐imidazole (I). A series of novel polyamides were prepared from the diamine monomer and various aliphatic and aromatic dicarboxylic acids via phosphorylation polyamidation. These polyamides are readily soluble in many organic solvents; their inherent viscosities ranged from 0.68 to 0.89 dl/g and gave tough and flexible films by solution‐casting. They had useful levels of thermal stability associated with relatively high T_gs (186–278°C), 10% weight loss temperatures in the range of 355–482°C, and char yields at 600°C in air up to 67%. All the polyamides have fluorescence emission in dilute (0.2 g/dl) DMAc solution with maxima at 425–495 nm and with the quantum yields in the range 14–28%. The chemiluminescence activity of polyamides was also studied in the presence of peroxyoxalate. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis of a new organogelator based on block structures of co‐oligoamide‐6

A series of new bisurea derivatives having in common two co‐oligoamide arms have been synthesized and characterized by NMR, SEC, DSC, SEM, and optical microscopy. These compounds are only soluble at high temperature in aprotic polar solvent. By cooling the solutions, gelation occurs if the concentration of these bisurea derivatives is higher than 3% (w/w). Comparisons with derivatives devoid of oligoamide arms leading no gelation suggest that two kinds of interaction are necessary to get the self‐assembling, namely intermolecular hydrogen‐bonding between urea groups and between oligoamide arms. As these interactions induce interconnections in several directions, the possibility of building the long classical fibrous structures is limited. Accordingly, the ultrastructure of the gel consists only of short interconnected fibers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4122–4129, 2008     

Influence of monofunctional reactants on the physical properties of dimer acid‐based polyamides

Dimer acid‐based polyamides were synthesized by condensation polymerization in the absence and presence of monofunctional reactants. Acetic acid, oleic acid and propyl amine were used as monofunctional reactants. The influences of the equivalent percentage (E%) and type of monofunctional reactant on the physical properties of dimer acid‐based polyamides such as glass transition temperature (T_g), melting point (T_m), heat of fusion (ΔH), degree of polymerization (DP), number average molecular weight (M_n), and kinematic viscosity were investigated. The molecular weight and viscosity of dimer acid‐based polyamides decreased with the increase in equivalent percentage of monofunctional reactant. Differential scanning calorimetry (DSC) studies showed that acetic acid and propyl amine had higher effect on the thermal properties of polyamides than that of oleic acid. In the case of polyamides prepared in the presence of acetic acid, the values of T_g, T_m, and ΔH of the polyamides increased remarkably with the increase in acetic acid content. On the contrary, propyl amine had a decreasing effect on the values of T_g, T_m, and ΔH of the polyamides. Incorporation of oleic acid into the polymer structure had no significant effect on the values of T_g and T_m of the dimer acid‐based polyamides. Copyright © 2006 John Wiley & Sons, Ltd.     

Microwave‐enhanced rapid synthesis of organosoluble polyamides based on 5‐(3‐acetoxynaphthoylamino)‐isophthalic acid

A series of photoactive polyamides (PAs) containing acetoxynaphthalamide side chain with inherent viscosities of 0.27–0.56 dl g^?1 were prepared by the direct polycondensation reaction of the 5‐(3‐acetoxynaphthoylamino)isophthalic acid with various commercially available diamines by means of triphenyl phosphite (TPP) and pyridine (Py) in the presence of calcium chloride and N‐methyl‐2‐pyrrolidone (NMP) under microwave irradiation and conventional heating conditions. Most of the resulting PAs are soluble in strong polar solvents such as N,N‐dimethylformamide (DMF), N,N‐dimethylacetamide, and NMP. Thermo‐gravimetric analysis (TGA) showed that polymers are thermally stable, 10% weight loss temperatures in excess of 320 and 378°C, and char yields at 600°C in nitrogen higher than 60%. These macromolecules exhibited maximum UV‐Vis absorption at 265 and 300 nm in a DMF solution. Their photoluminescence in the DMF solution demonstrated fluorescence emission maxima around 361 and 427 nm for all of the PAs. Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis and characterization of aromatic polymers containing pendant silyl groups. II. Aromatic polyamides

In order to improve the solubility of aromatic polyamides without significant loss of thermal stability, synthesis of aromatic polyamides containing pendant silyl groups was carried out by direct polycondensation of silylated aromatic diacids such as 2-trimethylsilylterephthalic acid (TSTA), 2,5-bis (trimethylsilyl) terephthalic acid (BTSTA), 5-trimethylsilylisophthalic acid (TSIA), 5-dimethylphenylsilylisophthalic acid (DMSIA), and 5-triphenylsilylisophthalic acid (TPSIA) with various aromatic diamines. The resulting polyamides had inherent viscosities in the range of 0.18–1.10 dL/g and showed improved solubilities toward aprotic polar solvents such as NMP, DMF, DMSO, etc. The prepared aromatic polyamides exhibited fairly good thermal stabilities, which were almost comparable to those of corresponding nonsubstituted aromatic polyamides. That is, thermogravimetric analysis (TGA) data revealed 10% weight losses at 358–500°C and residual weights at 700°C were 46–67% under nitrogen atmosphere. © 1992 John Wiley & Sons, Inc.     

Synthesis,characterization, and properties of new sequenced poly(ether amide)s based on 2‐(4‐aminophenyl)‐5‐aminobenzimidazole and 2‐(3‐aminophenyl)‐5‐aminobenzimidazole

A set of new aromatic poly(ether amide)s containing benzimidazole groups and ethylene oxide sequences of different lengths were synthesized and characterized. The new polymers were prepared from two benzimidazole diamines, 2‐(4‐aminophenyl)‐5‐aminobenzimidazole and 2‐(3‐aminophenyl)‐5‐aminobenzimidazole, and various oligo(ethylene oxide)dibenzoyl chlorides. They exhibited good solubility in polar aprotic solvents and glass‐transition temperatures in the range of 125–300 °C (the longer the ethylene oxide spacer was, the lower the glass‐transition temperature was). The new polyamides were essentially amorphous, as observed by X‐ray diffraction measurements and confirmed by differential scanning calorimetry measurements, by means of which no melting endotherm was observed in any case. The decomposition temperatures, as revealed by thermogravimetric analysis in nitrogen, were about 400 °C for all of them, regardless of the length of the ethylene oxide content or the phenylene ring orientation (meta or para) of the diamine moiety. The number of ethylene oxide linkages per repeat unit also determined the water uptake. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1414–1423, 2006     

Polymers from a levopimaric acid–acrylonitrile Diels–Alder adduct: Synthesis and characterization

The Diels–Alder adduct of levopimaric acid with acrylonitrile was efficiently prepared from resin acids. Excellent addition reaction yields (ca. 95%) were obtained. The adduct was converted into polyamides by polycondensation with diamines. When the same adduct was subjected to a dehydrodecarboxylation reaction, a novel ketone dinitrile derivative was obtained. This trifunctional product was also converted into polyamides by polycondensation with diamines. When the ketone dinitrile was hydrolyzed in the presence of alkalies and the reaction product was chlorinated, a ketone diacid chloride was obtained. A polyester was synthesized by the polycondensation of the diacid chloride with a diol. The structures of the Diels–Alder adduct, ketone dinitrile derivative, ketone diacid chloride, and polymers were established by means of elemental analysis, IR and NMR spectroscopy, and molecular weight determinations. Both the polyamides and the polyester were low‐molecular‐weight polymers soluble in polar solvents. The thermal behavior of the monomers and polymers was evaluated by thermogravimetric analysis. The thermal studies showed that the polymers were fairly thermostable substances, except the polyester, which appeared to be a substance with good thermal stability. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6308–6322, 2005     

Synthesis and properties of soluble aromatic polyamides derived from 2,2′‐bis(4‐carboxyphenoxy)‐9,9′‐spirobifluorene

The synthesis of a new bis(ether carboxylic acid), 2,2′‐bis(4‐carboxyphenoxy)‐9,9′‐spirobifluorene, in which two orthogonally arranged carboxyphenoxyfluorene entities are connected through an sp³ carbon atom (the spiro center), is reported. The direct phosphorylation polycondensation of this diacid monomer with various aromatic diamines yields aromatic polyamides containing 9,9′‐spirobifluorene moieties in the main chain. The presence of the spiro segment restricts the close packing of the polymer chains and decreases interchain interactions, resulting in amorphous polyamides with enhanced solubility, and high glass‐transition temperatures and good thermal stability are maintained through controlled segmental mobility. The glass‐transition temperatures of these polyamides are in the range of 234–306 °C, with 10% weight losses occurring at temperatures above 530 °C. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1160–1166, 2003     

Synthesis and characterization of new soluble aromatic polyamides derived from 1,4‐Bis(4‐carboxyphenoxy)‐2, 5‐di‐tert‐butylbenzene

Aromatic polyamides based on a novel bis(ether‐carboxylic acid) were synthesized by the direct phosphorylation condensation method. 1,4‐Bis(4‐carboxyphenoxy)‐2,5‐di‐tert‐butylbenzene was combined with various diamines containing flexible linkages and side substituents to render a set of eight novel aromatic polyamides. The polymers were produced with high yields and moderate to high inherent viscosities (0.49–1.32 dL/g) that corresponded to weight‐average and number‐average molecular weights (by gel permeation chromatography) of 31,000–80,000 and 19,000–50,000, respectively. Except for a single example, the polyamides were essentially amorphous and soluble in a variety of common solvents such as cyclohexanone, dioxane, and tetrahydrofuran. They showed glass‐transition temperatures of 250–295 °C (by differential scanning calorimetry) and 10% weight loss temperatures above 460 °C, as revealed by thermogravimetric analysis in nitrogen. Polymer films, obtained by casting from N,N‐dimethylacetamide solutions, exhibited good mechanical properties, with tensile strengths of 83–111 MPa and tensile moduli of 2.0–2.2 GPa. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 475–485, 2001     

Synthesis and characterization of new polyamides based on Diphenylaminoisosorbide

New aromatic polyamides were synthesized by the microwave‐assisted polycondensation of an optically active isosorbide‐derived diamine with different diacyl chlorides in the presence of a small amount of N‐methylpyrrolidinone. Polymers with inherent viscosities between 0.22 and 0.73 dL/g were obtained corresponding to molecular weights up to 140,000 g/mol. With interfacial polymerization or the Higashi method, lower molecular weight polymers were obtained with inherent viscosities in the range of 0.04–0.36 dL/g. Differential scanning calorimetry measurements clearly demonstrated the high thermal stability of these polymers (mp = 180–300 °C) and the absence of decomposition. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6480–6491, 2005     

Synthesis and properties of aromatic polyamides based on a benzonorbornane bis(ether carboxylic acid)

A set of new aromatic polyamides containing ether and benzonorbornane units were synthesized by the direct phosphorylation polycondensation of 3,6‐bis(4‐carboxyphenoxy)benzonorbornane with various aromatic diamines. The polymers were produced in high yields and moderate to high inherent viscosities (0.64–1.70 dL/g). The polyamides derived from rigid diamines such as p‐phenylenediamine and benzidine were semicrystalline and insoluble in organic solvents. The other polyamides were amorphous and organosoluble and afforded flexible and tough films via solution casting. These films exhibited good mechanical properties, with tensile strengths of 95–101 MPa, elongations at break of 13–25%, and initial moduli of 1.97–2.33 GPa. The amorphous polyamides showed glass‐transition temperatures between 176 and 212 °C (by differential scanning calorimetry) and softening temperatures between 194 and 213 °C (by thermomechanical analysis). Most of the polymers did not show significant weight loss before 450 °C in nitrogen or in air. Some properties of these polyamides were also compared with those of homologous counterparts without the pendent norbornane groups. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 947–957, 2002     

Synthesis and characterization of novel soluble triphenylamine‐containing aromatic polyamides based on N,N′‐bis(4‐aminophenyl)‐N,N′‐diphenyl‐1,4‐phenylenediamine

A new triphenylamine‐containing aromatic diamine, N, N′‐bis(4‐aminophenyl)‐N, N′‐diphenyl‐1,4‐phenylenediamine, was prepared by the condensation of N,N′‐diphenyl‐1,4‐phenylenediamine with 4‐fluoronitrobenzene, followed by catalytic reduction. A series of novel aromatic polyamides with triphenylamine units were prepared from the diamine and various aromatic dicarboxylic acids or their diacid chlorides via the direct phosphorylation polycondensation or low‐temperature solution polycondensation. All the polyamides were amorphous and readily soluble in many organic solvents such as N, N‐dimethylacetamide and N‐methyl‐2‐pyrrolidone. These polymers could be solution cast into transparent, tough, and flexible films with good mechanical properties. They had useful levels of thermal stability associated with relatively high glass‐transition temperatures (257–287 °C), 10% weight‐loss temperatures in excess of 550 °C, and char yields at 800 °C in nitrogen higher than 72%. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2810–2818, 2002     

Mixed‐valence class I transition and electrochemistry of bis(triphenylamine)‐based aramids containing isolated ether‐linkage

A series of solution‐processable electrochromic (EC) aromatic polyamides with bis(triphenylamine)ether (TPAO) units in the backbone were prepared by the phosphorylation polyamidation from a newly synthesized diamine monomer, bis(N‐4‐aminophenyl‐N‐4‐methoxyphenyl‐4‐aminophenyl)ether, and various dicarboxylic acids. These polymers were highly soluble in many organic solvents and showed useful levels of thermal stability associated with high glass‐transition temperatures and high char yields (higher than 50 at 800 °C in nitrogen). The polymer films showed reversible electrochemical oxidation and electrochromism with high contrast ratio in the visible range, which also exhibited moderate coloration efficiency (CE), low switching time, and good stability. Especially, the polyamides with two electroactive nitrogen centers only showed one‐stage oxidative coloring (no intervalence charge‐transfer [IV‐CT] band was detected), implying the two electrons are simultaneously removed from the TPAO units on account of the ether‐linkage definitely isolated the two redox centers. The mixed‐valence (MV) Class I/II/III transition and electrochemistry of the synthesized model compounds were investigated for the bridged triarylamine system with various N? N distances and intramolecular electron transfer (ET) capability. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Blue‐light‐emitting and anodically electrochromic materials of new wholly aromatic polyamides derived from the high‐efficiency chromophore 4,4′‐dicarboxy‐4″‐methyltriphenylamine

A series of organosoluble, aromatic polyamides were synthesized from a 4‐methyl‐substituted, triphenylamine‐containing, aromatic diacid monomer, 4,4′‐dicarboxy‐4″‐methyltriphenylamine, which is a blue‐light (454‐nm) emitter with a fluorescence quantum efficiency of 46%. These triphenylamine‐based, high‐performance polymers had strong fluorescence emissions in the blue region with high quantum yields up to 64% and one reversible oxidation redox couple around 1.20 V versus Ag/AgCl in acetonitrile solutions. They exhibited good thermal stability, with 10% weight loss temperatures above 480 °C under a nitrogen atmosphere and with relatively high glass‐transition temperatures (252–309 °C). All the polyamides revealed excellent stability of electrochromic characteristics, changing color from the original pale yellow to blue. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4095–4107, 2006     

Biodegradable polymers based on renewable resources. II. Synthesis and biodegradability of polyesters containing furan rings

A series of polyesters were synthesized by the bulk polycondensations of the respective combinations of two difuranic diesters, i.e., bis(5-(methoxycarbonyl)-2-furyl)methane ( 4a ) and 1,1-bis(5-(methoxycarbonyl)-2-furyl)ethane ( 4b ), with two 1,4 : 3,6-dianhydrohexitols [1,4 : 3,6-dianhydro-D -glucitol ( 1 ) and 1,4 : 3,6-dianhydro-D -mannitol ( 2 )], four aliphatic diols, and three oligo(ethylene glycol)s. The polycondensations were carried out at 220–230°C in the presence of titanium isopropoxide as a catalyst, giving polyesters having number average molecular weight up to 2.4 × 10⁴. These polyesters are soluble in a variety of solvents including chlorinated hydrocarbons, 1,4-dioxane, dimethyl sulfoxide, dimethylformamide, and sulfolane. Soil-burial tests along with enzymatic degradation experiments showed that these polyesters are potentially biodegradable. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2729–2737, 1997     

Synthesis and properties of new halogen‐substituted polyamides from 5‐halo‐m‐phenylenediamines and both aliphatic and aromatic dicarboxylic acids

New halogen‐substituted aromatic–aliphatic and wholly aromatic polyamides with high inherent viscosities were synthesized by the direct polycondensation of 5‐halo‐m‐phenylenediamines, where the halogens were Cl, Br, and I, with both aliphatic and aromatic dicarboxylic acids in N‐methyl‐2‐pyrrolidone with a mixture of triphenyl phosphite and pyridine as a condensing agent. The solubility of the halogen‐substituted polyamides was much higher than that of the parent polyamides derived from m‐phenylenediamine. The glass‐transition temperatures of the substituted aromatic–aliphatic polyamides increased in the order Cl < Br < I, whereas the temperatures of 10% weight loss in air decreased in the reverse order. The limiting oxygen index values, as an indication of flammability, increased for the substituted aromatic–aliphatic polyamides in the order Cl < Br < I. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3911–3918, 2000