Reaction Of Pyromellitic Dianhydride Research Articles

Synthesis and characterization of heterocyclic, and optically active poly(amide-imide)s by phosphorylation polycondensation

N,N′-Pyromelliticdiimido-di-L-methionine (1), N,N′-Pyromelliticdiimido-di-L-alanine (2), N,N′-Pyromelliticdiimido-di-L-phenylalanine (3) , and N,N′-Pyromelliticdiimido-di-L-leucine (4) were prepared from the reaction of Pyromellitic dianhydride with corresponding L-amino acids in a mixture of glacial acetic acid and pyridine solution (3/2 ratio) under refluxing conditions. The phosphorylation polycondensation of the corresponding diimide-diacid monomers with 4-phenyl-2,6-bis(4-aminophenyl) pyridine (6) or 4-(p-methylthiophenyl)-2,6-bis(4-aminophenyl) pyridine (8) were carried out in N-methyl-2-pyrolidone (NMP). The resulting poly (amide-imide)s were obtained in quantitative yields, showed admirable inherent viscosities (0.20-0.97 dl g-1), were soluble in polar aprotic solvents, showed good thermal stability and high optical purity. The synthetic compounds were characterized by IR, MS, 1H NMR and 13C NMR spectroscopy, elemental analysis and specific rotation.

A simple method to prepare poly(amic acid)-modified biomass for enhancement of lead and cadmium adsorption

A modified biomass of baker's yeast was prepared by grafting poly(amic acid), which was obtained via reaction of pyromellitic dianhydride (PMDA) and thiourea, onto the biomass surface at 50 °C for 4 h. This method was simpler than other reported chemical grafting methods. The presence of poly(amic acid) on the biomass surface was verified by FTIR, X-ray photoelectron spectroscopy (XPS) and microscope analyses, and the amount of carboxylate and amide groups in the biomass surface were found to be 1.36 and 0.7 mmol g −1 through potentiometric titration. Compared with the pristine biomass, the adsorption capacity of the modified biomass increased 15- and 11-fold for Cd 2+ and Pb 2+, respectively. According to the Langmuir equation, the maximum uptake capacities ( q m) for lead and cadmium were 210.5 and 95.2 mg g −1, respectively. The kinetics for cadmium and lead adsorption followed the pseudo-second-order kinetics. FTIR and XPS demonstrated that carboxyl, amide, and hydroxyl groups were involved in the adsorption of lead and cadmium, and the adsorption mechanism for the two metal ions included ion exchange, electrostatic interaction and complexation.

Microstructure and Thermomechanical Properties of Polyimide‐Silica Nanocomposites

Novel polyimide‐silica nanocomposites with interphase chemical bonding have been prepared using the sol‐gel process. The morphology, thermal and mechanical properties were studied as a function of silica content and compared with the similar composites having no interphase interaction. The polyimide precursors, polyamic acids (PAAs) with or without pendant hydroxyl groups were prepared from the reaction of pyromellitic dianhydride with a mixture of oxydianiline and 1,3 phenylenediamine or 2,4‐diminophenol in dimethylacetamide. The PAA with pendant hydroxyl groups was reacted with isocyanatopropyltriethoxysilane to produce alkoxy groups on the chain. The reinforcement of PAA matrices with or without alkoxy groups on the chain was carried out by mixing appropriate amount of tetraethoxysilane (TEOS) and carrying out its hydrolysis and condensation in a sol‐gel process. Thin hybrid films were imidized by successive heating up to 300C∘. The presence of alkoxy groups on the polymer chain and their cocondensation with TEOS developed the silica network which was interconnected chemically with the polyimide matrix. SEM studies show a drastic decrease in the silica particle size in the chemically bonded system. Higher thermal stability and mechanical strength, improved transparency, and low values of thermal coefficient of expansion were observed in case of chemically bonded composites.

Synthesis and characterization of novel optically active poly(amide–imide)s via direct amidation

N, N′-Pyromelliticdiimido-di- l-methionine ( 3) was prepared from the reaction of pyromellitic dianhydride ( 1) with l-methionine ( 2) in glacial acetic acid and pyridine solution at refluxing temperature. The direct polycondensation reaction of the monomer diimide–diacid ( 3) with 1,3-phenylenediamine ( 4a), 1,4-phenylenediamine ( 4b), 2,6-diaminopyridine ( 4c), 3,5-diaminopyridine ( 4d), 4,4′-diaminodiphenylether ( 4e) and 4,4′-diaminodiphenylsulfone ( 4f) was carried out in a medium consisting of triphenyl phosphate, N-methyl-2-pyrolidone, pyridine and calcium chloride. The resulting poly(amide–imide)s having inherent viscosities 0.45–0.53 dl g −1 were obtained in high yields and are optically active and thermally stable. All of the above compounds were fully characterized by IR spectroscopy, elemental analyses and specific rotation. Some structural characterization and physical properties of these new optically active poly(amide–imide)s are reported.

Thermoplastic poly(ester‐imide)s derived from anhydride‐terminated polyester prepolymer and diisocyanate

AbstractThe phase‐separation behavior of thermoplastic poly(ester‐imide) [P(E‐I)] multiblock copolymers, (A‐B)n, was investigated by a stepwise variation of the imide content. All the multiblock copolymers were synthesized by solution polycondensation with dimethylformamide as a solvent. P(E‐I)s were prepared with anhydride‐terminated polyester prepolymer and diisocyanates. Polyester prepolymers were prepared by the reaction of pyromellitic dianhydride and two different polyols [poly(tetramethylene oxide glycol) (PTMG) and polycaprolactone diol (PCL)]. Structural determination was done with Fourier transform infrared spectroscopy and Fourier transform NMR, and the molecular weight was determined by gel permeation chromatography. The effect of the imide content on the thermal properties of the synthesized P(E‐I)s was investigated by thermogravimetric analysis and differential scanning calorimetry. The polymers were also characterized for static and dynamic mechanical properties. Thermal analysis data indicated that the polymers based on PTMG were stable up to 330 °C in nitrogen atmosphere and exhibited phase‐separated morphology. Polymers based on PCL showed multistage decomposition, and the films derived from them were too fragile to be characterized for static and dynamic mechanical properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 341–350, 2004

Synthesis and Characteristics of Poly[N,N‘-diphenyl-N,N‘-bis(4-aminobiphenyl)-(1,1‘-biphenyl)-4,4‘-diamine pyromellitimide] as a Hole Injecting and Transporting Layer for Hybrid Organic Light-Emitting Device

A novel hole injecting and transporting polymer, poly[N,N‘-diphenyl-N,N‘-bis(4-aminobiphenyl)-(1,1‘-biphenyl)-4,4‘-diamine pyromellitimide] (PMDA-DBABBD PI), was obtained by thermal imidization from its poly(amic acid) (PAA) made by the reaction of pyromellitic dianhydride with the DBABBD that was chemically reduced from N,N‘-diphenyl-N,N‘-bis(4-nitrobiphenyl)-(1,1‘-biphenyl)-4,4‘-diamine synthesized through the palladium-catalyzed amination. The materials were characterized by using 1H NMR, 13C NMR, FT-IR, HR GC-MS, EA, and DSC. The characteristics of the PAA or PI thin films were investigated with XPS and an impedance spectroscopy. The hybrid light-emitting devices (HOLEDs) with the PAA and PI thin films were fabricated to examine the performance of the polymeric thin films as a hole injecting and transporting layer. The PI thin film having the glass transition temperature of 200 °C showed stable characteristics in the application for the HOLED whereas the PAA thin film seemed to be unstable. The power ...

Novel 3D Network: From the Reaction of Polyamine with Pyromellitic Dianhydride

Under mild condition, the reaction of pyromellitic dianhydride with polyamine in methanol solution results in ammonium carboxylate salts rather than amide polymer. X-ray analysis indicates a manifestation of 3D network linked by N-H + > O m > H-N + hydrogen bonding for the three ammonium salts, in which the porous spaces are filled with water molecules.

Novel 3-D Network: From the Reaction of Polyamine with Pyromellitic Dianhydride

Under mild condition the reaction of pyromellitic dianhydride with polyamine in methanol solution results in ammonium carboxylate salts rather than amide polymer. X-ray analysis indicates a manifestation of 3-D network linked by N─H+…O− H─N+ hydrogen bonding for the three ammonium salts, in which the porous spaces are filled with water molecules.

Novel method for preparation of poly(benzoxazinone-imide)

A novel method was developed to prepare poly(benzoxazinone-imide) by the dealcoholization of poly(amide-imide), having pendent ethoxycarbonyl groups, which was prepared from poly(amide acid). The poly(amide acid) was prepared from the reaction of pyromellitic dianhydride and 4,4'-diamino-6-ethoxycarbonyl benzanilide. The curing behavior of the poly(amide acid) was monitored by DSC, which indicated the presence of two broad endotherms, one with maximum at 153 °C due to imide-ring formation and the other with maximum at 359 °C due to benzoxazinone-ring formation. The poly(amide acid) was thermally treated at 300 °C/1 h to get poly(amide-imide) with pendent ester groups, then at 350 °C/2 h to convert into poly(benzoxazinone-imide) by dealcoholization. Viscoelastic measurements of the poly(amide-imide) showed that the storage modulus dropped at about 280 °C with glass-transition temperature (T g ) at about 340 °C. The storage modulus of poly(benzoxazinone-imide), however, was almost constant up to 400 °C and no T g was detected below 400 °C. Also, the tensile modulus and tensile strength of the poly(benzoxazinone-imide was much higher than that of the poly(amide-imide). The 5% decomposition of poly(benzoxazinone-imide) film was at 535 °C, which reflects its excellent thermal stability. Also, poly(benzoxazinone-imide) showed more hydrolytic stability against alkali in comparison to polyimides.

High resolution electron energy loss spectroscopy study of vapor deposited pyromellitic dianhydride and oxydianiline films on Cu(110)

The reaction of pyromellitic dianhydride (PMDA) and oxydianiline (ODA) on Cu(110) was studied using high resolution electron energy loss spectroscopy (HREELS). The interaction of the individual monomers with Cu(110) was also studied. PMDA dissociated on Cu(110) at 300 K forming a carboxylate link to the surface, releasing CO into the gas phase. ODA was also found to adsorb dissociatively on Cu(110) at 300 K via cleavage of one of the amine NH bonds. Vapor-deposited PMDA/ODA films on Cu(110) reacted at 300 K to form polyamic acid. Heating a polyamic acid film to 450 K was sufficient to induce imidization and form polyimide. HREELS results indicated that the resulting polyimide chains were both bonded to the surface and terminated with PMDA monomer units. The polyimide film was stable up to 500 K, consistent with the thermal stability of PMDA on Cu(110).

Synthesis and characterization of alternating copolyimides containing two different diimide units

AbstractSoluble and stable precursors of aromatic imidodiamines were prepared and employed in polymerization reactions with aromatic dianhydrides to yield poly(amic acid ester)s. Thermal imidization of the polymers produced strictly aromatic copolyimides. The reaction of pyromellitic dianhydride (PMDA, 1c), 3,3′,4,4′‐ biphenylteracarboxylic dianhydride (BPDA, 1a), or 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA, 1b) with isopropyl alcohol produced a mixture of isomeric esters. These isomer mixtures were employed in amidation reactions without further separation. Direct amidation with ethyl chloroformate was employed. The acids were reacted with ethyl chloroformate in tetrahydrofuran and the resulting solutions were added slowly to solution of excess 1,4‐ or 1,3‐phenylendediamine in tetrahydrofuran. The reaction of diamines 5a–f with dianhydrides yielded poly(amic acid ester)s. The poly(amic acid ester)s were more stable against depolymerization during storage in solution compared with the corresponding poly(amic acid)s. Alternating copolyimides 6–11 had two different diimide units derived from PMDA (1c), BPDA (1a), or BTDA (1b). In differential scanning calorimetry (DSC) analyses, alternating copolyimides 7,9 and 11 containing 1,3‐phenylenediamine units exhibited distinct and reproducible glass transition temperatures, which were a little lower than the average values of corresponding homopolyimides and those of random copolyimides. But alternating copolyimides 6, 8, and 10, which contain 1,4‐phenylenediamine units, showed very weak glass transitions.

Preparation and characterization of negative photosensitive polysiloxaneimide

AbstractA photosensitive polysiloxaneimide precursor was synthesized from oxydianiline, bis(p‐aminophenoxy)dimethylsilane, and a diacid chloride. This diacid chloride was prepared by the reaction of thionyl chloride with a diacid, which resulted from the reaction of pyromellitic dianhydride with hydroxyethylacrylate in N‐methylpyrrolidone (NMP). The adhesion properties between polyimide and substrates such as SiO2 wafer were improved with introduction of siloxane moiety into the polyimide chain. The dielectric constant decreased with increasing siloxane moiety content. The photocrosslinking reaction results show that an 88–90% gel fraction was reached under the irradiation of a high‐pressure mercury lamp. © 1995 John Wiley & Sons, Inc.

X-ray photoemission studies on vapour-phase-deposited polyamide films

In this article we describe the preparation of thick polyamide (PA) films of poly(4,4′-oxy-bis( p-phenylene)terephthalamide) by co-deposition of terephthalolyldichloride (TDC) and 4,4′-oxydianiline (ODA) under high vacuum conditions. The molecules react in the condensed phase with elimination of hydrochloric acid to form polyamide. Chlorine-containing molecules are entrapped in the polymer matrix and are released only by annealing to temperatures of 523K. X-ray photoelectron spectroscopy (XPS) and infrared absorption (FTIR) measurements show that the reaction between TDC and ODA is essentially complete at room temperature, and that only small changes in the overall stoichiometry take place by annealing to higher temperatures. Attempts to produce PA by co-condensation of dimethylterephthalate (DMT) and ODA were not successful, presumably due to the high activation barrier for the reaction between the ester and the diamine in the absence of a catalyst. The experiments and XPS results will be compared to those of polyimide formed by the reaction of pyromellitic dianhydride (PMDA) and ODA. The apparent deficit in O1s and C1s carbonyl intensity for polyamide and polyimide cannot be accounted for by deviations from stoichiometry and are explained by final state effects in the photoemission process.

Preparation of negative photoreactive polyimide and its characterization

AbstractIn this article, a polyimide precursor was synthesized from oxydianiline and a diacid chloride. This diacid chloride was prepared by the reaction of thionyl chloride with a diacid, which resulted from the reaction of pyromellitic dianhydride with cinnamyl alcohol in N‐methylpyrrolidone (NMP). The photoresist, made from the above polyimide precursor, was spincoated onto silicon wafers, prebaked, and then exposed to UV light with a high pressure Hg lamp. The pattern generation process was also investigated. The appropriate conditions of the photolithographic procedures, involving photoresist compounding, spin coating, prebaking, exposure, development, rinse, postbaking, etc., were determined. The experimental results show that the photoresist exhibited excellent thermal stability and adequate photosensitivity.

The reaction of pyromellitic dianhydride with 4,4′‐diaminodiphenylmethane

AbstractThe homogeneous polyaddition reaction of pyromellitic dianhydride with 4,4′‐diaminodiphenylmethane was investigated. The dependence of the number average molecular weights on time has a maximum; low equilibrium values of M̄n are caused by a disturbed equimolarity of functional groups due to the hydrolysis of dianhydride with water present in the solvent. In the course of establishment of the equilibrium M̄n value, the molecular weight distribution changes to the most probable value.

Synthesis and structural studies of new copolyimides 2. Influence of pyromellitimide rings on copolymer structure

AbstractThe reaction of pyromellitic dianhydride (1,2 : 4,5‐benzenetetracarboxylic dianhydride) (1) with L‐ and D‐alanine (2L) and (2D) leads to new monomers which were used to synthesize new copolymers. These copolymers were obtained as a product of the condensation of optical isomers of bis[N‐(1‐chloroformylethyl)]pyromellitimides (CFEP) with poly(ethylene glycol) PEG‐2000 (5). The effect of monomer structure on the structure and thermal properties of the polymers was studied using X‐ray diffraction, differential scanning calorimetry and thermogravimetry. The copolymers were compared with similar copolyimides obtained previously from bis(N‐chloroformylmethyl)pyromellitimide and poly(ethylene glycol), PEG 2000. The dominating effect of poly(ethylene glycol) comonomer on the crystallinity, structure and thermal stability of these new copolymers is proven.

Curing of polyimides

AbstractThe imidization of films of the polyamic acid obtained from reaction of pyromellitic dianhydride (PMDA) with oxydianiline (ODA) was studied by dynamic mechanical thermal analysis (with the Polymer Labs DMTA), Two process regions are observed. The first process is characterized by decomplexation of the NMP/polyamic acid complex, plasticization, and imidization. The heating rate determines the character of the first process. At high temperatures (above 300°C) the second process becomes apparent. It is connected to the increase in chain mobility at these temperatures which allow molecular packing processes (densification, ordering) to occur. The ordering leads to an increase of the storage modulus. The particular transition temperature increases with annealing time.

Polyimide materials based on pyromellitic dianhydride for the separation of carbon dioxide and methane gas mixtures

The sorption and transport of carbon dioxide and methane in a series of dense polyimide films were examined to evaluate these materials for gas separation applications. The polyimides described in this study are based on the reaction of pyromellitic dianhydride (PMDA) with oxydianiline (ODA), methylene dianiline (MDA), or isopropylidene dianiline (IPDA). The carbon dioxide permeabilities for this series of compounds increased in the order: PMDA-ODA < PMDAMDA<PMDA-IPDA, while the permselectivity increased in the opposite order: PMDA-IPDA < PMDA-MDA < PMDA-ODA. Sorption studies coupled with mixed gas permeability measurements demonstrated that the trends in permeabilities and permselectivities were due primarily to differences in the mobilities of the gases in the various films. The trends observed for permeabilities and selectivities were correlated with trends in the macroscopic densities and average intersegmental distance for each film as measured by wide angle X-ray diffraction. These results indicated that in addition to intrachain motions, interchain spacing differences are contributing, if not dominating, factors in understanding differences in the transport behavior of gas through these polyimide films.

Effects of various factors on the formation of high molecular weight polyamic acid

AbstractThe reaction of pyromellitic dianhydride (PMDA) and aromatic diamine in an aprotic solvent such as dimethylacetamide (DMAc) gives a solution of poly(amic acid). The effects of certain variables on the polymerization and some additives on the stability and imidization of the poly(amic acid)s were studied. It was found that the addition of PMDA portionwise to the solution of diamine always keeps the excess diamine in solution and enables one to obtain the highest molecular weight of poly(amic acid). When the addition process was reversed, either by the change or dehydration of solvent, a high molecular weight was not attained. The inevitable water in the solvent or the reaction medium is the major factor, and the more the water content in the solvent or the reaction medium, the larger is the probability of destruction of PMDA during the reaction and hence low molecular weight is obtained. If very pure monomers were used in the polymerization, the 1:1 of molar ratio is the optimum value. Excess diamine or dianhydride results in the exchange reaction with poly(amic acid) and causes a rapid degradation of polymer chain. This exchange reaction was proved by NMR measurements. The presence of electrophilic agents or the nucleophilic agents containing active protons in the poly(amic acid) solution promotes the decomposition of polymer and causes the brittleness of polyimide film in the curing process. Using acetic anhydride (A) to convert the poly(amic acid) to polyimide, pyridine (P) can protect the polymer chain from the nucleophilic attack by the anhydride. The mixture with proper ratio of A/P (1/1–15/1) can be used as good dehydrating agents.Meanwhile, according to the results to the results of experiments, we suggested the probable reaction mechanisms about how the water, amine, and anhydride destroy the polyamic acid chains.

Preparation of silicon‐containing polymers. I. Polyimides from dianhydrides and organosilicon diisocyanates

AbstractNew silicon‐containing polyimides have been prepared by the reaction of pyromellitic dianhydride (PMDA) and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) with organosilicon diisocyanates having the following general structure: magnified image where R1 = R2 = CH3 and C6H5. Thermal properties of these polyimides were studied were by TG, DTA, and DTG.