Fluorinated polyamides and poly(amide imide)s based on 1,4‐bis(4‐amino‐2‐trifluromethylphenoxy)benzene,aromatic dicarboxylic acids,and various monotrimellitimides and bistrimellitimides: Syntheses and properties

A CF₃‐containing diamine, 1,4‐bis(4‐amino‐2‐trifluromethylphenoxy) benzene ( I ), was prepared from hydroquinone and 2‐chloro‐5‐nitrobenzotrifluoride. Imide‐containing diacids ( V _a–h and VI _a,b ) were prepared through the condensation reaction of amino acids, aromatic diamines, and trimellitic anhydride. Then, a series of soluble fluorinated polyamides ( VII _a–h ) and poly(amide imide)s ( VIII _a–h and X _a,b ) were synthesized from I with various aromatic diacids ( II _a–h ) and imide‐containing diacids ( V _a–h and VI _a,b ) via direct polycondensation with triphenyl phosphate and pyridine. The polyamides and poly(amide imide)s had inherent viscosities of 1.00–1.70 and 0.79–1.34 dL/g, respectively. All the synthesized polymers showed excellent solubility in amide‐type solvents such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, and N‐dimethylformamide and afforded transparent and tough films via solvent casting. Polymer films of VII _a–h , VIII _a–h , and X _a,b had tensile strengths of 91–113 MPa, elongations to break of 8–40%, and initial moduli of 2.1–2.8 GPa. The glass‐transition temperatures of the polyamides and poly(amide imide)s were 254–276 and 255–292 °C, respectively, and the imide‐containing poly(amide imide)s had better thermal stability than the polyamides. The polyamides showed higher transparency and were much lighter in color than the poly(amide imide)s, and their cutoff wave numbers were below 400 nm. In comparison with isomeric IX _{c – h} , poly(amide imide)s VIII _c–h exhibited less coloring and showed lower yellowness indices. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3116–3129, 2004     

Synthesis of Methyl—substituted Phthalazinone—based Aromatic Poly（amide imide）s

A series of novel aromatic poly (amide imide)s containing phthalazinone moietics were prepared from 2-(4-aminophenyl)-4-[3-methyl-4-(4-aminophenoxy)-2,3-phthalazinone-1], a novel diamine 1 with our diimide-dicarboxylic acids by Yamazaki phosphorylation method with the inherent viscosity of 0.36-0.65 dL/g. These polymers had high glass transition temperatures above 300℃ and they lost 10% weight between 426-475℃ in N2. The structure of diamine 1 and the polymers was confirmed by IR,^1H NMR and MS. The obtained polymers were readily soluble in polar solvents such as NMP,m-cresol etc. and easily cast into tough,flexible films. The X-ray indicated that they are all amorphous.     

Preparation,characterization and thermal degradation study of poly(amide imide)s based on tri-component mixture of PMDA/BTDA,diamines and acid chloride

A series of poly(amide imide)s (PAIs) having alternate (amide–amide) and (imide–imide) units (polymers 1–14 and 22–35), and random distribution of amide-imide linkages (polymers 15–21 and 36–42) were prepared by low temperature solution polymerization of benzene-1,2,4,5-tetracarboxylic dianhydride (PMDA)/benzophenone-3,3′,4,4′-tetracarboxylic dianhydride (BTDA), diamines (cyclic and aromatic) and acid chloride in dimethylforamide. All the polymers were readily soluble in polar aprotic solvents with inherent viscosities in the range of 0.134–0.878. The process of cycloimidization of poly(amide amic acid)s (PAAs) to PAIs was investigated by TGA and FT-IR techniques at four different temperatures i.e., 175, 200, 225, and 260 °C. The rate of cycloimidization was calculated by taking into account the theoretical weight loss (W_T), obtained from [n × M_w (H₂O)/M_w (R_U)] W, where M_w (H₂O) molecular weight of water, W weight of PAA taken for TGA, M_w (R_U) the molecular weight of repeat unit of PAA, n number of water molecules eliminated per repeat unit of PAA upon cycloimidization. For a particular diamine, the extent of percentage cycloimidization at the end of the isothermal heating was higher for PAAs containing trimellitic anhydride chloride (TMAc) unit, irrespective of the nature of the dianhydride and diamine. Thermal and thermooxidative degradation of PAIs was investigated by TGA in nitrogen and oxygen atmosphere. The initial decomposition temperatures (IDT) of polymers are above 260 °C, and vary widely (from 260 to 501 °C) depending upon the structure of the polymer backbone. PAIs containing TMAc exhibited higher thermal stability as compared to those polymers having diacid chloride units, in both N₂/O₂ atmospheres.     

Convenient Method of Chain‐Growth Polycondensation for Well‐Defined Aromatic Polyamides

Summary: For the convenient synthesis of well‐defined poly(N‐octyl‐p‐benzamide)s with low polydispersities, the polycondensation of methyl 4‐octylaminobenzoate ( 1 ) was investigated. Methyl ester monomer 1 polymerized with lithium 1,1,1,3,3,3‐hexamethyldisilazide (LHMDS) in the presence of an initiator in tetrahydrofuran at −10 °C. The highly pure polyamide with a defined molecular weight and a low polydispersity is obtained after simple treatment of the reaction mixture with aqueous NaOH solution, followed by evaporation.

The chain‐growth polycondensation of 4‐octylaminobenzoic acid methyl ester ( 1 ) with lithium 1,1,1,3,3,3‐hexamethyldisilazide (LHMDS) to yield poly(N‐octyl‐p‐benzamide).     

Novel Flame‐Retardant and Thermally Stable Poly(Amide‐imide)s Based on Bicyclo[2,2,2]oct‐7‐Ene‐2,3,5,6‐Tetracarboxylic Diimide and Phosphine Oxide in the Main Chain: Synthesis and Characterization

Six novel poly(amide‐imide)s PAIs 5a‐f were synthesized through the direct polycondensation reaction of six chiral N,N′‐(bicyclo[2,2,2]oct‐7‐ene‐tetracarboxylic)‐bis‐L‐amino acids 3a‐f with bis(3‐amino phenyl) phenyl phosphine oxide 4 in a medium consisting of N‐methyl‐2‐pyrrolidone (NMP), triphenyl phosphite (TPP), calcium chloride (CaCl₂) and pyridine. The polymerization reaction produced a series of flame‐retardant and thermally stable poly(amide‐imide)s 5a‐f with high yield and good inherent viscosity of 0.39–0.83 dLg^?1. The resultant polymers were fully characterized by means of FTIR, ¹H NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation and solubility tests. Thermal properties and flame retardant behavior of the PAIs 5a‐f were investigated using thermal gravimetric analysis (TGA and DTG) and limited oxygen index (LOI). Data obtained by thermal analysis (TGA and DTG) revealed that these polymers show good thermal stability. Furthermore, high char yields in TGA and good LOI values indicated that resultant polymers exhibited good flame retardant properties. N,N′‐(bicyclo[2,2,2]oct‐7‐ene‐tetracarboxylic)‐bis‐L‐amino acids 3a‐f were prepared in quantitative yields by the condensation reaction of bicyclo[2,2,2]oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride 1 with L‐alanine 2a , L‐valine 2b , L‐leucine 2c , L‐isoleucine 2d , L‐phenyl alanine 2e and L‐2‐aminobutyric acid 2f in acetic acid solution. These polymers can be potentially utilized in flame retardant thermoplastic materials.     

MALDI-TOF质谱表征聚芳醚酮环状低聚物及其组分分布

应用介质辅助激光解吸离子化飞行时间质谱(MALDI-TOFMS),以二羟基苯甲酸为介质、N₂(337nm)为激光源,对两种聚芳醚酮环状低聚物的结构进行了确认,研究了环状低聚物不同聚合度组分的分布规律,并且与GPC质量分析法作了比较,实验结果表明,MALDI-TQF质谱是分析环状低聚物的准确、快速的工具之一.     

Aromatic polybenzoxazoles containing ether–sulfone linkages

A series of poly(o‐hydroxy amide)s having both ether and sulfone linkages in the main chain were synthesized via the low‐temperature solution polycondensation of 4,4′‐[sulfonylbis(1,4‐phenylene)dioxy]dibenzoyl chloride and 4,4′‐[sulfonylbis(2,6‐dimethyl‐1,4‐phenylene)dioxy]dibenzoyl chloride with three bis(o‐aminophenol)s including 4,4′‐diamino‐3,3′‐dihydroxybiphenyl, 3,3′‐diamino‐4,4′‐dihydroxybiphenyl, and 2,2‐bis(3‐diamino‐4‐hydroxyphenyl)hexafluoropropane. Subsequent thermal cyclodehydration of the poly(o‐hydroxy amide)s afforded polyethersulfone benzoxazoles. Most of the poly(o‐hydroxy amide)s were soluble in polar organic solvents such as N‐methyl‐2‐pyrrolidone; however, the polybenzoxazoles without the hexafluoroisopropylidene group were organic‐insoluble. The polybenzoxazoles exhibited glass‐transition temperatures (T_g) in the range of 219–282 °C by DSC and softening temperatures (T_s) of 242–320 °C by thermomechanical analysis. Thermogravimetric analyses indicated that most polybenzoxazoles were stable up to 450 °C in air or nitrogen. The 10% weight loss temperatures were recorded in the ranges of 474–593 °C in air and 478–643 °C in nitrogen. The methyl‐substituted polybenzoxazoles had higher T_g's but lower T_s's and initial decomposition temperatures compared with the corresponding unsubstituted polybenzoxazoles. For a comparative purpose, the synthesis and characterization of a series of sulfonyl polybenzoxazoles without the ether group that derived from 4,4′‐sulfonyldibenzoyl chloride and bis(o‐aminophenol)s were also reported. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2262–2270, 2001     

Synthesis and characterization of novel heat resistant poly(amide imide)s

A series of new poly(amide imide)s was prepared from new diacid containing sulfone, ether, amide and imide groups with various aromatic diamines. The diacid was synthesized via four steps, starting from reaction of 4-aminophenol with 4-nitrobenzoyl chloride in the presence of propylene oxide afforded N-(4-hydroxy phenyl)-4-nitrobenzamide. In the second step, reduction of nitro group resulted in preparation of 4-amino-N-(4-hydroxy phenyl) benzamide. In the next step for the preparation of diamine, the reaction of 4-amino-N-(4-hydroxy phenyl) benzamide with bis-(4-chlorophenyl) sulfone in the presence of K₂CO₃ was achieved. The prepared sulfone ether amide diamine was reacted with two moles of trimellitic anhydride to synthesize related sulfone ether amide imide diacid. The precursors and final monomer were characterized by FT-IR, H-NMR and elemental analysis. Direct polycondensation reaction of the sulfone ether amide imide diacid with different diamines in the presence of triphenyl phosphite afforded five different poly (sulfone ether amide imide amide)s. The obtained polymers were fully characterized and their physical properties including thermal behavior, thermal stability, solubility, and inherent viscosity were studied.     

Syntheses and properties of fluorinated polyamides and poly(amide imide)s based on 9,9-bis[4-(4-amino-2-trifluromethylphenoxy)phenyl]fluroene, aromatic dicarboxylic acids, and various monotrimellitimides and bistrimellitimides

A diamine, 9,9-bis[4-(4-amino-2-trifluromethylphenoxy)phenyl]fluroene (I) containing the CF₃ group, was prepared from 9,9-bis(4-hydroxyphenyl)fluorene and 2-chloro-5-nitrobenzotrifluoride. The imide-containing diacids (V _a-j and VI _a,b) were prepared by condensation reaction of amino acids, aromatic diamines, and trimellitic anhydride. Then, a series of soluble fluorinated polyamides (VII _a-e) and poly(amide imide)s (VIII _a-j and X _a,b) were synthesized from diamine (I) with various aromatic diacids II _a-h and the imide-containing diacids (V _a-j and VI _a,b) via direct polycondensation with triphenyl phosphate and pyridine. All polymers showed excellent solubility in amide-type solvents such as N-dimethylforamide and can also be dissolved in pyridine, m-cresol, and tetrahydrofuran. Polymers afford transparent and tough films by solvent casting. The glass transition temperature of these polymers were in the range of 278–366°C, and the poly(amide imide)s had better thermal stability than polyamides. In comparison with the isomeric IX _a-d, VIII _a-d showed a lighter color with lower b* (yellowness index) values than the corresponding IX series.     

Cyclic poly(lactide)s via the ROPPOC method catalyzed by alkyl‐ or aryltin chlorides

A comparison of tributyltin chloride, dibutyltin dichloride, and butyltin trichloride as catalysts of ring‐opening polymerizations (ROPs) of l‐lactides at 160 °C in bulk reveals increasing reactivity in the above order, but only the least reactive catalysts, Bu₃SnCl, yield a uniform reaction product, namely cyclic poly(L‐lactide)s with weight average molecular weights (M_w's) in the range of 40,000–80,000. A comparison of dimethyltin , dibutyltin , and diphenyltin dichlorides resulted in the following order of reactivity: Me₂SnCl₂ < Bu₂SnCl₂ < <Ph₂SnCl₂. In this series also, the most reactive catalyst yields cyclic polylactides, but the extent of cyclization varies with the molecular weight. The formation of cyclic polylactides is explained by ROP combined with simultaneous polycondensation involving end‐to‐end cyclization (ROPPOC method). ROP of meso‐lactide at 80 or 60 °C yields even‐numbered linear chains as main products, a result supporting the ROPPOC mechanism. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 952–960     

Synthesis of novel poly(hydroxyether terephthalate) via polyaddition of 2,5-difluoroterephthalic acid with aromatic bis(epoxide)s

A novel and more reliable synthetic route to 2,5-difluoroterephthalic acid was developed. A series of new poly(hydroxyether terephthalate) were prepared by the polyaddition of 2,5-difluoroterephthalic acid with various aromatic bis(epoxide)s catalyzed by tetrabutyl ammonium bromide.     

Aromatic polyamides derived from unsymmetrical diamines containing the phthalazinone moiety

Two unsymmetrical and kink non‐coplanar heterocyclic diamines, 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)phenyl](2H)phthalazin‐1‐one and 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)‐3,5‐dimethylphenyl](2H) phthalazin‐1‐one, were successfully synthesized by readily available heterocyclic bisphenol‐like monomers through two steps in high yields. A series of novel poly(arylene ether amides)s containing the phthalazinone moiety with inherent viscosities of 1.16–1.67 dL/g were prepared by the direct polymerization of novel diamines and aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents. The polymers were readily soluble in a variety of solvents such as N,N‐dimethylformamide, N,N‐dimethylacctamide, dimethyl sulfoxide, N‐methyl‐2‐pyrrolidone, and even in pyridine, chloroform and m‐cresol. The glass‐transition temperatures were in the range of 291–329 °C, and the temperatures for 5% weight loss in nitrogen were above 490 °C. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3489–3496, 2002     

Poly(ester amide)s derived from L‐tartaric acid and amino alcohols. II. Aregic polymers

A series of aregic poly(ester amide)s (a‐PEAT6) with ester/amide ratios (a : b) varying from 1 : 19 to 1 : 2 were prepared with L ‐tartaric acid, 6‐aminohexanol, and 1,6 hexanediamine as the starting materials. Polycondensation in a solution of the diamine with mixtures of pentachlorophenyl‐activated di‐O‐methyl‐L ‐tartaric and 6‐aminohexyl‐di‐O‐methyl‐L ‐tartaric acids led to a‐PEAT6(a : b), with the a : b ratio determined by the composition of the feed. The newly synthesized poly(ester amide)s were characterized by elemental analysis, size exclusion chromatography, and IR and NMR spectroscopy. They had number‐average molecular weights between 25,000 and 45,000 and were highly crystalline, showing melting temperatures ranging from 100 to 230 °C and glass‐transition temperatures oscillating between 50 and 100 °C. The thermal degradation of a‐PEAT6(a : b) began above 200 °C and concluded with a final weight loss between 60 and 90% of the initial mass. The process evolved with the formation of cyclic tartarimide units and extensive main‐chain scissions. The degradation mechanism is discussed in relation to the chemical composition and microstructure of the polymers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2687–2696, 2000     

Preparation and Properties of Novel Aromatic Polyamides from Diamines Containing 4,5-Imidazolediyl Structure

Novel aromatic polyamides were prepared from aromatic diamine containing 4,5-imidazolediyl unit, either by low temperature solution polycondensation or by direct polycondensation. Used diamines were 4,5-bis(4-aminophenyl)-2-phenylimidazole 1, 4,5-bis[4-(4-aminophenyl)]-2-(4-methylphenyl)imidazole 2 and 4,5-bis[4-(4-aminophenoxy)phenyl]-2-phenylimidazole 3. The obtained aromatic polyamides were produced with moderate to high inherent viscosity and soluble in polar aprotic solvents such as N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Thermogravimetric analysis showed those polymers were stable up to 422°C in nitrogen atmosphere. The glass transition temperature (T _g)s of the polymers derived from diamine 3 were in the range between 243 and 275°C, and these values were approximately 120–160°C lower than those analogue polyamide I series containing no phenoxy units. The properties of polyamide I series are also compared with those of analogue polymers that order of aromatic nuclei and amide linkage is reversible.     

Syntheses and properties of polyamides from ether diacid having the spirobichroman unit

A novel hexamethylspirobichroman (HMSBC) unit-containing dicarboxylic acid, 6,6′-bis(4-carboxyphenoxy)-4,4,4′,4′,7,7′-hexamethyl-2,2′-spirobichroman ( 3 ), was derived from nucleophilic substitution of p-fluorobenzonitrile with the phenolate ion of 6,6′-dihydroxy-4,4,4′,4′,7,7′-hexamethyl-2,2′-spirobichroman ( 1 ), followed by alkaline hydrolysis of the intermediate bis(ether nitrile). Using TPP and pyridine as condensing agents, a series of polyamides with inherent viscosities in the range of 0.82–1.14 dL/g were prepared by the direct polycondensation of dicarboxylic acid 3 with various aromatic diamines. All the obtained polymers were noncrystalline and soluble in various organic solvents such as N,N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP). Except for the polymer derived from benzidine, the other polyamides could be solution cast into transparent and tough films, and their tensile strengths, elongations at break, and tensile moduli were in the range of 56–76 MPa, 4–59%, and 1.6–2.0 GPa, respectively. These polyamides had glass transition temperatures in the range of 183–200°C with 10% weight loss above 420°C. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1479–1486, 1997     

Gas transport properties of soluble poly(amide imide)s

The influence of the molecular structure of five soluble poly(amide imide)s (PAI)s on their gas transport properties for carbon dioxide, oxygen, nitrogen, and methane has been studied. Permeabilities, diffusivities, and solubilities were determined by time lag measurements and correlated to chain packing and mobility as well as to polymer gas interaction. The PAIs were characterized by small‐ and wide‐angle X‐ray scattering. Molar masses and polymerization degrees were measured by light scattering. Additionally, glass transition temperatures, densities, and persistence lengths were determined. Pressure‐ and temperature‐dependent gas transport measurements have been done. It was found that the permeability is increasing with the diffusion coefficient which can be related to the fractional free volume. PAIs containing cardo diamines show higher diffusivities and permeabilities than poly(amide imide)s containing linear aromatic diamines due to higher fractional free volumes. The solubilities for PAIs containing the same imide compound correlate with the molar cohesive energy density. The exchange of hydrogen to fluorine atoms at one aromatic ring of the diamine increases the fractional free volume and cohesive energy density and, in consequence, the diffusion and solubility coefficient. Arrhenius behavior was observed for temperature dependence and decreasing permeability with increasing pressure. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2183–2193, 1999     

Synthesis and characterization of poly(aryl amide imide)s derived from diphenyltrimellitic anhydride

The synthesis and characterization of a series of novel poly(aryl amide imide)s based on diphenyltrimellitic anhydride are described. The poly(aryl amide imide)s, having inherent viscosities of 0.39–1.43 dL/g in N-methyl-2-pyrrolidinone at 30°C, were prepared by polymerization with aromatic diamines in N,N-dimethylacetamide and subsequent chemical imidization. All the polymers were amorphous, readily soluble in aprotic polar solvents such as DMAC, NMP, dimethylsulfoxide, N,N-dimethylformamide, and m-cresol, and could be cast to form flexible and tough films. The glass transition temperatures were in the range of 284–366°C, and the temperatures for 5% weight loss in nitrogen were above 468°C. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4541–4545, 1999     

Synthesis and characterization of new optically active poly(amide‐imide)s containing epiclon and L‐methionine moieties in the main chain

Epiclon [3a,4,5,7a‐tetrahydro‐7‐methyl‐5‐(tetrahydro‐2,5‐dioxo‐3‐furanyl)‐1,3‐isobenzofurandione] (1) was reacted with L ‐methionine (2) in acetic acid and the resulting imide‐acid 3 was obtained in high yield. The diacid chloride 4 was prepared from diacid derivative 3 by reaction with thionyl chloride. Thermostable poly(amide‐imide)s containing epiclon structure were synthesized by reacting of diacid chloride 4 with various aromatic diamines. Polymerization reaction was performed by two conventional methods: low temperature solution polycondensation and short period reflux conditions. In order to compare conventional solution polycondensation reaction methods with microwave‐assisted polycondensation, the reactions were also carried out under microwave conditions with a small amount of o‐cresol that acts as a primary microwave absorber. The reaction mixture was irradiated for 6 min with 100% radiation power. Several new optically active poly(amide‐imide)s with inherent viscosity ranging from 0.15 to 0.36 dl/g were obtained with high yield. All of the above polymers were fully characterized by ¹H‐NMR, FT‐IR, elemental analyses and specific rotation techniques. Some structural characterizations and physical properties of these new optically active poly(amide‐imide)s are reported. Copyright © 2005 John Wiley & Sons, Ltd.     

Preparation and properties of new poly(amide‐imide)s based on 1,4‐bis(4‐trimellitimidophenoxy)naphthalene and aromatic diamines

A diimide dicarboxylic acid, 1,4‐bis(4‐trimellitimidophenoxy)naphthalene (1,4‐BTMPN), was prepared by condensation of 1,4‐bis(4‐aminophenoxy)naphthalene and trimellitic anhydride at a 1 : 2 molar ratio. A series of novel poly(amide‐imide)s (IIa–k) with inherent viscosities of 0.72 to 1.59 dL/g were prepared by triphenyl phosphite‐activated polycondensation from the diimide‐diacid 1,4‐BTMPN with various aromatic diamines (Ia–k) in a medium consisting of N‐methyl‐2‐pyrrolidinone (NMP), pyridine, and calcium chloride. The poly(amide‐imide)s showed good solubility in NMP, N,N‐dimethylacetamide, and N,N‐dimethylformamide. The thermal properties of the obtained poly(amide‐imide)s were examined with differential scanning calorimetry and thermogravimetry analysis. The synthesized poly(amide‐imide)s possessed glass‐transition temperatures in the range of 215 to 263°C. The poly(amide‐imide)s exhibited excellent thermal stabilities and had 10% weight losses at temperatures in the range of 538 to 569°C under a nitrogen atmosphere. A comparative study of some corresponding poly(amide‐imide)s also is presented. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1–8, 2000