New types of heat-resistant,flame-retardant ferrocene-based polyamides with improved solubility

A novel ferrocenyl diamine (FDA) was prepared by the condensation reaction of 1,1′-ferrocenedicarbonyl chloride with 2 mol of 2,6-bis(4-aminophenoxy)pyridine. A series of ferrocene-based polyamides was prepared via polycondensation reaction of FDA with various diacid chlorides in N-methyl-2-pyrrolidone (NMP) using trimethylchlorosilane (TMSCl) as activating agent. The monomer and polyamides were characterized and inherent viscosity, solubility, thermal stability and behavior, flame-retardancy, and crystallinity of the polymers were studied. The polymers showed good heat-resistant, flame-retardancy, and also improved solubility in polar aprotic solvents.     

Polyimides based on furanic diamines and aromatic dianhydrides: synthesis,characterization and properties

Novel polyimides containing furan moieties were prepared from the resulting furanic diamine monomers with various aromatic dianhydrides including 1,2,4,5-benzene-tetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, and hexafluoroisopropylidene 2,2-bis(phthalic anhydride), via a two-step process. The resulting polyimides were characterized by solubility tests, viscosity measurements, FTIR, ¹H NMR spectroscopy, differential scanning calorimetric (DSC), and thermogravimetric analysis (TGA) analysis. The polyimides with inherent viscosities in the range of 0.048–0.095 L/g showed excellent solubility in aprotic amide and organic solvents, such as N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, dimethylformamide and acetone, chloroform, etc. DSC showed glass transition temperatures (T _g) in the range of 116–143 °C. These polymers showed excellent thermal stability up to 390 °C.     

Poly(ether-imide) and poly(ether-imide)-polydimethyl-siloxane containing isopropylidene groups

Summary A poly(ether-imide) was prepared by thermal imidization of poly(amic-acid) intermediate resulting from the solution polycondensation reaction of a bis(ether-anhydride), namely 2,2′-bis-[(3,4-dicarboxyphenoxy)phenyl]-1,4-phenylene-diisopropylidene dianhydride, with an aromatic diamine containing two isopropylidene groups, namely 4,4′-(1,4-phenylenediisopropylidene)bisaniline. A poly(ether-imide)-polydimethylsiloxane copolymer was prepared by polycondensation reaction of the same bis(ether-anhydride) with an equimolar quantity of the aromatic diamine having isopropylidene groups and a bis(aminopropyl)polydimethylsiloxane oligomer of controlled molecular weight. A solution imidization procedure was used to convert quantitatively the poly(amic-acid) intermediates to the corresponding polyimides. The polymers were easily soluble in polar organic solvents and showed good thermal stability with decomposition temperature being above 400 °C. Electrical insulating properties of poly(ether-imide)-polydimethylsiloxane copolymer film were evaluated on the basis of dielectric constant and dielectric loss and their variation with frequency and temperature.     

Poly(ether ether sulfone)s and sulfonated poly(ether ether sulfone)s derived from functionalized 1,1‐diphenylethylene derivatives

Symmetrically disubstituted 1,1‐diphenylethylene derivatives, 1,1‐bis[4‐(t‐butyldimethylsiloxy)phenyl]ethylene and 1,1‐bis(4‐hydroxyphenyl)ethylene, were prepared by new synthesis methods and employed as functionalized monomers in the preparation of new poly(ether ether sulfone) derivatives, with the introduction of the 1,1‐diphenylethylene unit along the polymer backbone. A series of parent 1,1‐diphenylethylene based poly(ether ether sulfone)s were prepared via (a) the cesium fluoride catalysed polycondensation reactions of dihalogenated diaryl sulfones with silylated bisphenols and (b) the base catalysed aromatic nucleophilic substitution polycondensation reaction between aromatic dihalogenated diaryl sulfones with bisphenols. The post‐polymerization sulfonation reaction via the thiol‐ene addition reaction of the poly(ether ether sulfone) precursor containing the 1,1‐diphenylethylene unit along the backbone, with sodium 3‐mercapto‐1‐propane sulfonate, afforded well‐defined sulfonated poly(ether ether sulfone), with the alkyl sulfonate group introduced pendant to the polymer backbone. The organic compounds and different polymer derivatives were characterized by standard chromatography, spectroscopy, spectrometry, thermal analyses, microscopy and X‐ray diffraction measurements. © 2016 Society of Chemical Industry     

Poly(ether ketone azomethane)s and poly(ether ketone imide)s containing naphthylene moieties

A new diamine monomer, 1,5-bis[4-(4-aminophenoxy)]benzoyl-2,6-dimethoxynaphthalene, was synthesized via a Friedel–Crafts acylation reaction followed by an aromatic nucleophilic substitution reaction. Six ether–ketone linked polymers, named as poly(ether ketone azomethane)s and poly(ether ketone imide)s, were successfully prepared through the polycondensations of the diamine monomer with dialdehydes and dianhydrides, respectively. These naphthylated polymers exhibited high T _g values (142–288 °C), due to their bulky and rigid chemical structure. Meanwhile, they showed good thermal stability and improved solubility. Typically, some of them were casted into thin flexible film and showed high moduli.     

Heat stable and organosoluble polyimides containing laterally-attached phenoxy phenylene groups

In this research a diamine monomer containing two phenoxy phenylene lateral groups, 2,2′-bis[(p-phenoxy phenyl)]-4,4′-diaminodiphenyl ether (PPAPE) was used to prepare novel wholly aromatic polyimides by thermal or chemical two-step polycondensation reactions. Comonomers including pyromellitic dianhydride (PMDA), 4,4′-oxydiphthalic anhydride (ODPA), and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) were used for the polyimidization reactions. A reference polyimide was also prepared by the reaction of 4,4′-diaminodiphenyl ether (DADPE) with pyromellitic dianhydride (PMDA). The limited viscosity numbers as well as [`(M)]<sub>n</sub> \overline{M}_n and [`(M)]_w \overline{M}_w values of the resulting polymers were determined. All PPAPE-resulted polyimides had excellent organosolubility in common polar solvents. A low crystallinity extent was only observed using their wide-angle X-ray diffractograms (WAXD). The prepared hinged polyimides could also be cast into transparent and flexible films. The glass transition temperatures of the resulting polyimides were determined by differential scanning calorimetry (DSC) analyses. The thermograms obtained from thermogravimetric analyses (TGA) showed that the phenoxy phenylene lateral groups attached to the macromolecular backbones had no substantial diminishing effect on the thermal stability of these structurally-modified polyimides.     

Synthesis,characterization, and study of thermal properties of methyl-substituted arylene sulfone ether polyimides,polyamides, and poly(amide–imides)

A number of methyl-substituted bis[(phenyleneoxy) sulfone] dianilines were synthesized and reacted with pyromellitic dianhydride (PMDA), benzophenone tetracarboxylic acid dianhydride (BTDA), terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), and trimellitic anhydride acid chloride (TMAC) to prepare a series of polyimides, polyamides, and poly(amide–imides), respectively. Low temperature solution and interfacial polymerization techniques were utilized to prepare the above polymers. Most of the polymers prepared formed tough, transparent flexible films. The prepared polymers were characterized by solution viscosity, thermal gravimetric analysis (dynamic and isothermal), and differential scanning calorimetry. The effect of the number and the ring substitution of methyl groups on polymer properties is discussed.     

Preparation and properties of novel thermally stable pyridine‐based poly(amide imide amide)s

The 2,6‐bis(4‐nitrobenzamido)pyridine was prepared via reaction of 2,6‐diaminopyridine with two moles of 4‐nitrobenzoyl chloride in the presence of propylene oxide. Catalytic reduction of nitro groups of 2,6‐bis(4‐nitrobenzamido)pyridine with hydrazine yielded 2,6‐bis(4‐aminobenzamido)pyridine. Reaction of this diamine with two moles of trimellitic anhydride afforded a diacid with preformed amide and imide structures. Poly(amide imide amide)s were prepared by direct polycondensation reactions of the diacid with different diamines in the presence of triphenyl phosphite. All the precursors and polymers were fully characterized using common spectroscopic methods and elemental analysis and physical properties of the polymers including solution viscosity, thermal stability, thermal behavior, and solubility were studied. According to the obtained results the polymers showed high thermal stability and enhanced solubility. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of a new diamine and its effect on the residual stress of colorless polyimide

A new diamine was designed and synthesized to improve the flexibility of colorless polyimides by reducing residual stress. Four variations of colorless polyimides with the same dianhydride (4,4′-(hexafluoroisopropylidene)-diphthalic) and four different diamines (bis[4-(3-aminophenoxy)-phenyl] sulfone, bis(3-aminophenyl) sulfone, 2,2′-bis(trifluoromethyl)benzidine, and 2,2-bis(4-aminophenyl)-hexafluoropropane) were used. A series of colorless polyimides were prepared by adding the new diamine. The carbon and ether bonds between the benzene rings of the new diamine affected the flexibility and optical properties of colorless polyimide. The synthesis of the new diamine was confirmed by NMR measurements. Furthermore, the decrease in residual stress at room temperature and the glass transition temperature was confirmed. The effect of the new diamine was most evident for polyimide with a bulky and rigid structure. Though a slight yellow color appears because of the broken charge transfer complex balance, controlling the content of the new diamine will allow application of polyimides in flexible display.     

Synthesis of soluble and thermally stable poly[arylene ether amide (N‐arylenebenzimidazole)]s

Poly(arylene ether)s containing N‐arylenebenzimidazole and amide groups were prepared using an aromatic nucleophilic displacement reaction that replaced the N‐H sites from four different bis(benzimidazolyl) derivatives with activated aromatic difluorides containing ether and amide groups in sulfolane. The reaction was carried out at 210 °C in the presence of anhydrous potassium carbonate. The structures of the polymers were characterized by means of Fourier transform infrared, ¹H NMR spectroscopy and elemental analysis, and the results were largely consistent with the proposed structure. All resulting polymers showed an essentially amorphous nature. This was consistent with the calculated results. Differential scanning calorimetry and thermogravimetric measurements showed that the polymers had high glass transition temperatures (>190 °C), good thermostability and high decomposition temperatures (>400 °C). These novel polymers also showed easy solubility. Copyright © 2012 Society of Chemical Industry     

Synthesis,characterization, and thermal stability of novel wholly para-oriented aromatic poly(ether-amide-hydrazide)s bearing pendant groups and their corresponding poly(ether-amide-1,3,4-oxadiazole)s

Four novel wholly para-oriented aromatic poly(ether-amide-hydrazide)s containing various pendant groups on their aromatic rings were synthesized from p-aminosalicylic acid hydrazide (PASH) with an equimolar amount of either 4,4′-(1,4-phenylenedioxy)dibenzoyl chloride (1a), 4,4′-(2,5-tolylenedioxy)dibenzoyl chloride (1b), 4,4′-(2-tert-butyl-1,4-phenylenedioxy)dibenzoyl chloride (1c), or 4,4′-(2,5-biphenylenedioxy)dibenzoyl chloride (1d) via a low temperature solution polycondensation reaction. A polyamide-hydrazide without the ether and pendant groups, poly[4-(terephthaloylamino)salicylic acid hydrazide, PTASH, is also investigated for comparison. It was synthesized from PASH and terephthaloyl chloride by the same synthetic route. The polymer intrinsic viscosities ranged from 4.5 to 2.47 dlg⁻¹ in N,N-dimethyl acetamide (DMAc) at 30 °C and decreased with the introduction of the ether and pendant groups into the polymer. All the polymers were soluble in DMAc, N,N-dimethyl formamide (DMF), and N-methyl-2-pyrrolidone (NMP) and their solutions could be cast into flexible films with good mechanical strengths. Further, they exhibited a great affinity to water sorption. Their solubility and hydrophilicity increased with introduction of the ether and pendant groups into the polymer. The prepared polymers could be thermally cyclodehydrated under nitrogen atmosphere into the corresponding poly(ether-amide-1,3,4-oxadiazole)s approximately in the region of 300–450 °C. The introduction of the flexibilizing ether linkages and the pendant groups into the polymer improves the solubility of the resulting poly(ether-amide-1,3,4-oxadiazole)s compared to poly(amide-1,3,4-oxadiazole) free from these groups.     

Synthesis and properties of novel polyamides containing sulfone‐ether linkages and xanthene cardo groups

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     

Synthesis and characterization of new polyamides and polyimides containing dioxypyrimidine moiety in the main chain with bulky imidazole pendent group: solubility, thermal and photophysical properties

A new symmetrical diamine monomer containing dioxypyrimidine and two diaryl imidazole bulky pendent group was synthesized by the nucleophilic substitution reaction of 4,6 dihydroxy pyrimidine with the synthesized 2-(2-chloro-5-nitrophenyl)-4,5-diphenyl-1H-imidazole (I). A series of novel fluorescent imidazole-containing polyamides (PAs) with inherent viscosities of 0.52–0.78 dL/g was prepared by direct polycondensation of the diamine with various dicarboxylic acids. These PAs were readily soluble in many organic solvents and could be solution-cast into tough and flexible films. The PAs exhibited glass transition temperatures (T_g)s between 202 and 260 °C, and 10% weight loss temperatures in the range of 345–470 °C in air. In addition, three novel polyimides (PIs) with inherent viscosities of 0.38–0.56 dL/g were prepared by addition reaction of the diamine with commercially available tetracarboxylic dianhydrides and subsequent chemical imidization. The PIs exhibited good solubility in polar solvents such as NMP. These polymers exhibited T_gs in the range of 237–285 °C and their 10% weight-loss temperatures varied from 440 to 520 °C.     

Synthesis and characterization of polyimides and co-polyimides having pendant benzoic acid moiety

A novel diamine monomer, 2,4-diamino-4′-carboxy diphenyl ether had been synthesized. Several polyimides were prepared by reacting this diamine with commercially available dianhydrides, such as benzophenone tetracarboxylic acid dianhydride (BTDA), 4,4′-bis{hexafluoroisopropylidene bis (phthalic anhydride)}(6-FDA), oxydiphthalic anhydride (ODPA) and 3,3′,4,4′-biphenyltetracarboxylic acid dianhydride (BPDA). Furthermore, copolymers from the resulting diamine and oxydianiline (ODA) with 6 FDA were also synthesized. The inherent viscosities of the polymers were 0.42-0.67 dl g⁻¹. The polymers have good solubility in polar aprotic solvents, high thermal stability up to 410 °C in nitrogen and high glass transition temperatures (T_g) ranging from 260-330 °C. These polymers formed tough flexible films by solution casting.     

Synthesis and characterization of poly(amide imides) containing benzimidazole-rings

New poly(amide imides) were prepared from benzimidazole-ring containing diamine via one-pot synthetic method. The diamine monomer, 6,4′-diamino-2-phenylbenzimidazole, was prepared from 4-nitrobenzoyl chloride and 4-nitro-1,2-phenylenediamine with 3 steps. It was found that the degree of imidization of the poly(amide imides) containing benzimidazole-ring can be controlled by monomer composition and solution imidization conditions. All partially imidized poly(amide imides) were soluble in polar aprotic solvent, but became insoluble in any organic solvents after thermal curing. The thermal stability of the poly(amide imides) increased as the polymers contain more benzimidazole units. Received: 6 March 1997/Accepted 2 April 1997     

Synthesis and properties of fluorinated polyimides and fluorinated poly(imide amide)s containing pendent cyano groups

A series of fluorinated polyimides and fluorinated poly(imide amide)s containing pendent cyano groups were prepared and investigated to determine their dielectric constants as a function of relative humidity and thermal characteristics. The fluorinated polymides and fluorinated poly(imide amide)s containing pendent cyano groups were prepared by reaction of bis(4-aminophenoxy) benzonitriles with a fluorinated dianhydride and with a fluorinated di(acid chloride) containing preformed imide rings. The properties of the fluorinated polyimides and fluorinated poly(imide amide)s containing pendent cyano groups were compared with those of fluorinated polyimides and fluorinated poly(imide amide)s prepared from 1,3-bis(4-aminophenoxy)benzene. The introduction of the pendent cyano groups caused an increase in the dielectric constant and an increase in the glass transition temperature of the polymers compared with the polymers prepared without pendent cyano groups.     

Synthesis and properties of novel poly(aryl ether ketone)s containing imide linkages in the main chains

A new monomer containing imide linkages, bis[4-(p-phenoxybenzoyl)-1,2-benzenedioyl]-N,N,N′,N′-4,4′-diaminodiphenyl ether (BPBDADPE), was prepared by the Friedel–Crafts reaction of bis(4-chloroformyl-1,2-benzenedioyl)-N,N,N′,N′-4,4′-diaminodiphenyl ether (BCBDADPE) with diphenyl ether (DPE). Novel poly(aryl ether ketone)s containing imide linkages in the main chains (PEK-I) were synthesized by electrophilic Friedel–Crafts solution copolycondensation of terephthaloyl chloride (TPC) with a mixture of DPE and BPBDADPE. The polymers were characterized by different physico-chemical techniques. The polymers with 10–40 mol% BPBDADPE are semicrystalline and had increased T _gs over commercially available poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK) (70/30) due to the incorporation of imide linkages in the main chains. The polymers IV and V with 30–40 mol% BPBDADPE had not only high T _gs of 182–183 °C, but also moderate T _ms of 341–343 °C, having good potential for melt processing and exhibited high thermal stability and good resistance to common organic solvents.     

Synthesis and characterization of organosoluble and transparent polyimides derived from trans‐1,2‐bis(3,4‐dicarboxyphenoxy)cyclohexane dianhydride

A novel dianhydride, trans‐1,2‐bis(3,4‐dicarboxyphenoxy)cyclohexane dianhydride (1,2‐CHDPA), was prepared through aromatic nucleophilic substitution reaction of 4‐nitrophthalonitrile with trans‐cyclohexane‐1,2‐diol followed by hydrolysis and dehydration. A series of polyimides (PIs) were synthesized from one‐step polycondensation of 1,2‐CHDPA with several aromatic diamines, such as 2,2′‐bis(trifluoromethyl)biphenyl‐4,4′‐diamine (TFDB), bis(4‐amino‐2‐trifluoromethylphenyl)ether (TFODA), 4,4′‐diaminodiphenyl ether (ODA), 1,4‐bis(4‐aminophenoxy)benzene (TPEQ), 4,4′‐(1,3‐phenylenedioxy)dianiline (TPER), 2,2′‐bis[4‐(3‐aminodiphenoxy)phenyl]sulfone (m‐BAPS), and 2,2′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]sulfone (6F‐BAPS). The glass transition temperatures (T_gs) of the polymers were higher than 198°C, and the 5% weight loss temperatures (T_d5%s) were in the range of 424–445°C in nitrogen and 415–430°C in air, respectively. All the PIs were endowed with high solubility in common organic solvents and could be cast into tough and flexible films, which exhibited good mechanical properties with tensile strengths of 76–105 MPa, elongations at break of 4.7–7.6%, and tensile moduli of 1.9–2.6 GPa. In particular, the PI films showed excellent optical transparency in the visible region with the cut‐off wavelengths of 369–375 nm owing to the introduction of trans‐1,2‐cyclohexane moiety into the main chain. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42317.     

Preparation and Properties of Soluble,Thermally Stable Poly(Silyl ether amide)s and Related Silica Nanocomposites

Soluble poly(silyl ether amide)s and related nanocomposites with improved thermally stability was prepared. For this, a diamine was prepared through reaction of para-aminophenol with dichlorodiphenylsilane. Structure of diamine was confirmed with conventional spectroscopic methods. Poly(silyl ether amide)s was synthesized through polycondensation of diamine with different diacid chlorides. Properties of poly(silyl ether amide)s comprising thermal behavior, thermal stability, solubility, solution viscosity, and morphology were studied. Polymers showed high thermal stability and good solubility in organic solvents due to their unique structures. Related nanocomposites with different contents of silica nanoparticles (10–40?wt%) were prepared and their properties compared with pristine polyamides.     

Organosoluble,low‐dielectric‐constant fluorinated polyimides based on 2,6‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene

A novel fluorinated bis(ether amine) monomer, 2,6‐bis(4‐amino‐2‐trifluoromethylphenoxy) naphthalene, was prepared through the nucleophilic aromatic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and 2,6‐dihydroxynaphthalene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of novel trifluoromethylated polyimides were synthesized from the diamine with various commercially available aromatic tetracarboxylic dianhydrides using a two‐stage process with thermal imidization of poly(amic acid) films. Most of the resulting polyimides were highly soluble in a variety of organic solvents and could afford transparent and tough films via solution casting. These polyimides exhibited moderately high glass transition temperatures (T_gs) of 249–311 °C, high thermal stability and good mechanical properties. Low moisture (0.19–0.85 %), low dielectric constants (2.49–3.59 at 10 kHz), and low color intensity were also observed. For a comparative study, a series of analogous polyimides based on 2,6‐bis(4‐aminophenoxy)naphthalene were also prepared and characterized. Copyright © 2005 Society of Chemical Industry