Wide-angle X-ray Diffractometer Research Articles

Polymerization of acrylonitrile in dimethyl carbonate: A kinetic and mechanistic study

For the first time, a new polymerization medium, dimethyl carbonate (DMC), was used for the polymerization of acrylonitrile (AN), and polyacrylonitrile (PAN) powder was obtained successfully. The effects of polymerization factors, including monomer concentrations, temperature and initiator concentrations on the structures and properties of PAN powders were investigated by nuclear magnetic resonance spectroscopy (NMR), total internal reflectance Fourier transform infrared spectrometer (FTIR), wide-angle X-ray diffractometer (WXRD) and thermal gravimetric analyzer (TGA). The polymerization kinetic and mechanistic study of PAN with DMC as the polymerization medium were discussed in details. There are three key achievements in this paper. First, the kinetic equation of PAN polymerization with DMC as a medium was established: Rp = K[ABVN]0.92[AN]6.78. This result shows that the Rp is highly dependent on the AN concentrations. Second, the chain transfer constant of DMC was measured to be 4.57 × 10−4 at 60 °C, and the chain transfer constant increases with polymerization temperature. Lastly, the structures and properties of PAN powders prepared with H2O, tetrahydrofuran (THF) and DMC as media were compared. The results showed that the PAN prepared with DMC as a medium by free radical polymerization had a higher conversion, molecular weight and better crystalline property compared to THF. These findings indicate that DMC is a promising medium for manufacturing high quality PAN powder by free radical polymerization.

Growth of CuO nanoparticles using one step chemical bath deposition under microwave heating and their characterizations

Abstract Varied morphologies of crystalline copper oxide nanoparticles were synthesized using one step chemical bath deposition under microwave heating of prepared growth solution at 1200 W microwave power for a very short duration of 2–8 min. The structure and crystallinity of the as grown copper oxide nanoparticles were studied by wide angle X-ray diffractometer analysis. The particle size values obtained from Scherrer’s relation and the Williamson–Hall plot methods are in the 16–18 nm range. The approximate size of as grown copper oxide nanoparticles evaluated from field emission scanning electron microscopic images are in the range of approximately 15–20 nm. The presence of copper and oxygen was verified by energy dispersive X-ray spectroscopy analysis. Their weight % and atomic % exhibits the rich amount of development of copper oxide nanoparticles in a 1:1 stoichiometric ratio. The optical properties of as grown copper oxide nanoparticles were examined by assessing absorption spectra of the sample in ultraviolet–visible range. The significant peak of absorption spectra is seen near 340 nm wavelength which explains the mono-dispersion behaviour of nanoparticles. Evaluation of Urbach energy of copper oxide nanoparticles reveals that the nanomaterial has microstructural lattice disorder. These characterizations of as synthesized copper oxide nanoparticles explain the feasibility and potential of such nanomaterial to be incorporated in a wide range of utilities.

The influence of calcium chloride concentration on the mechanical and barrier properties of high amylose corn starch film

In this study, high amylose corn starch (HACS) films were prepared using CaCl2 as cosolvent. The interaction between CaCl2 and HACS during the preparation was investigated. Differences in physicochemical properties between HACS films with and without CaCl2 were characterized using wide-angle X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), water vapor permeability (WVP), thermogravimetric analysis (TG) and atomic force microscopy (AFM). The tensile strength and elongation at break increased to 27.01 ± 1.13 MPa and 17.4 ± 1.9%, respectively, CaCl2 had plasticizing effect and provided mechanical reinforcement to the formed HACS films. The reinforcement was mainly due to (ⅰ) CaCl2 increased the content of free amylose chains in the aqueous phase, and (ⅱ) chelation between Ca2+ and starch chains enhanced the entanglement between HACS chains. The results of XRD and FTIR indicated the crystalline region and shot-range orderliness of films decreased, CaCl2 significantly increased the dispersion of starch chains and made the HACS films more homogeneous. CaCl2 improved the barrier properties and surface morphology. The surface roughness of the HACS films decreased fromRa = 189 nm, Rq = 242 nm toRa = 103 nm, Rq = 152 nm as the concentration of CaCl2 increased. However, high concentration of CaCl2 destroyed the inner and surface structure of the film to some extent.

The effect of structure change from polymeric membrane to gel membrane on CO2 separation performance

Poly(ether-block-amide) (Pebax)/tricaproin (TCP) gel membranes were prepared for the first time with TCP content varying from 0 to 80 wt%. And the effect of structure change from Pebax polymeric membrane to Pebax/TCP gel membrane on CO2 separation was studied. Membrane morphology and crystallinity was characterized by scanning electron microscope (SEM) and wide-angle X-ray diffractometer (WAXRD). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC) were used to characterize the interaction and compatibility between Pebax and TCP. Thermal stability of the prepared membranes was conducted by thermal gravimetric analysis (TGA). With the increase of TCP content, the physical properties of Pebax/TCP gel membrane were approaching to liquid TCP. However, in comparison with liquid TCP, the weight loss temperature of TCP in Pebax/TCP gel membranes improved by almost 100 °C. Gas permeation test confirmed the monotonically increasing CO2 permeability with slight increase of CO2/H2 selectivity, and slight loss of CO2/N2 and CO2/CH4 selectivity from Pebax membrane to gel membrane with 80 wt% TCP. In addition, ascribing to the weakened diffusion control effect and higher solubility control effect, Pebax/TCP membranes showed a higher CH4 permeability than H2 permeability when the TCP content exceeded 40 wt%. Moreover, compared with Pebax membrane, Pebax/TCP gel membrane showed higher sensitivity to operating pressure. Under the testing condition of 35 °C and 6 KPa, Pebax/TCP 80 gel membrane showed CO2 permeability of 1673.2 Barrer with CO2/N2, CO2/CH4 and CO2/H2 selectivity of 15.3, 4.8 and 6.4, respectively.

Fast pyrolysis of silicones at low temperatures catalyzed by anatase titanium dioxide

Silicones are widely used in medical and engineering field for their remarkable properties. The resulting waste is an increasing economic and environmental problem. Pyrolysis can be a feasible way to recycle silicone waste. Since its high thermal stability, looking for an efficient catalyst becomes necessary. In this work, anatase titanium dioxide was found to be very efficient in catalyzing the pyrolysis of silicones even at extremely low temperatures. The pyrolysis rate, pyrolysis products, the catalytic mechanism of silicones and the reusability of catalyst were investigated in detail via thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), wide-angle X-ray diffractometer (wide angle XRD), thermogravimetric analysis-Fourier transform infrared spectroscopy (TG-FTIR), and pyrolysis-gas chromatography/mass spectroscopy (Py-GC/MS). During pyrolysis, polysiloxane chain undergoes catalyzed unzipping depolymerization. The catalytic mechanism is believed to be the nucleophilic attack of silicon in the main chain by the hydroxyl group on anatase titanium dioxide. This is the first report on pyrolysis of silicones catalyzed by anatase titanium dioxide. The blending of anatase titanium dioxide with polysiloxane may become a promising technology for inexpensive, high efficient and sustainable feature in feedstock recycling of silicones. In addition, this new discovery also offers guidance that fillers with such high active hydroxyl groups should be avoided in polysixoane composites.

Nickel Nanofibers Manufactured via Sol-Gel and Electrospinning Processes for Electrically Conductive Adhesive Applications

The electrospun fibers of poly(vinyl pyrrolidone) (PVP)-nickel acetate (Ni(CH3COO)2·4H2O) composite were successfully prepared by using sol-gel processing and electrospinning technique. Nickel oxide (NiO) nanofibers were obtained afterwards by high temperature calcinations of the precursor fibers, PVP/Ni acetate composite nanofibers, at 700 °C for 10 h. Following with the reduction of NiO nanofibers at 400 °C using hydrogen gas (H2) under inert atmosphere, the metallic nickel (Ni) nanofibers were subsequently produced. In addition, as-prepared Ni nanofibers were chemically coated with silver (Ag) nanoparticles to enhance their electrical property and prevent the surface oxidation. The characteristics of as-prepared fibers, such as surface morphology, fiber diameters, purity, the amount of NiO nanofibers, and metal crystallinity, were determined using a scanning electron microscope (SEM), a Fourier transform infrared spectrometer (FT-IR), a thermogravimetric analyzer (TGA), and a wide-angle x-ray diffractometer (WAXD). The volume resistivity of epoxy nanocomposite filled with Ag-coated short Ni nanofibers was lower than the one containing short Ni nanofibers with no coating due to the synergetic effect of Ag nanoparticles created during the coating process. We also demonstrated that the volume resistivity of epoxy nanocomposite filled with Ni nanofibers could be dramatically decreased by using Ni nanofibers in the non-woven mat form due to their small fiber diameter and high fiber aspect ratio, which yield a high specific surface area, and high interconnecting network.

The Thermal Behavior of γ-PA1010: Evolution of Structure and Morphology in the Simultaneous Thermal Stretched Films.

In this work, polyamide 1010 (PA1010) films were prepared by melt-quenching. A wide-angle X-ray diffractometer (WAXD) with a thermal stretching stage was used to investigate the structure transformation, crystallinity and degree of orientation in the course of simultaneous thermally stretched PA1010. The crystallinity increased along with the increase of draw ratio and then decreased as the draw ratio was over 2.00 times—which the maximum value reached when the draw ratio was about 2.00 times. The degree of orientation of γ-PA1010 was much greater at higher temperature than room temperature (RT); the difference gradually became weaker with the increase of draw ratio. There was a linear relationship between the draw ratios and tensile force at higher temperatures, and the tensile force increased with the increase of draw ratios. The tensile force may induce crystallization and promote orientation in the course of simultaneous thermally stretched PA1010. These phenomena are beneficial to understand the structure-processing-performance relationship and provide some theoretical basis for the processing and production.

Crystal Structure and Mechanical Properties of Uniaxially Stretched PA612/SiO2 Films.

Stretching has a significant effect on the microstructure and ultimate performance of semi-crystalline polymers. To investigate the effect of stretching on structure and mechanical properties of uniaxial stretched PA612/SiO2, PA612 and PA612/SiO2 films were prepared at four temperatures close to the glass transition temperature at various strain. The samples were characterized by a transmission electron microscope (TEM), wide-angle X-ray diffractometer (WAXD), Two-dimensional wide-angle X-ray Scattering (2D-WAXS), differential scanning calorimeter (DSC), dynamic mechanical analyzer (DMA), and stretching tests. The results showed that the α phase was the dominant phase in PA612 casting film, no obvious γ phase was observed, while both stretching and the presence of SiO2 can induce the generation of α phase and improve the crystallinity of PA612. Crystals were oriented along the stretching direction and the b axis was parallel to the equatorial direction after stretching. The interplanar spacing of (010/110) decreased with the increasing stretching temperature and expanded with the increasing strain, while stretching temperature and strain present negligible effect on the interplanar spacing of (100). The grain size increased with the stretching temperature while decreased with strain. The presence of SiO2 led to reduce the yield stress and the stress drop beyond yielding of the composite. Uniaxial stretching gave rise to a significant improvement in the fracture stress and the glass transition temperature.

Temperature and deformation dependence of structural evolution in polyamide 1010

Polyamide 1010 (PA1010) is a representative of long-chain polyamides, used in applications requiring good mechanical, thermal and chemical properties. It has a lower melting point and slightly higher flexible properties compared to nylon 66. Very few reports have been focused on the structures and properties of long-chain polyamides, which brings some troubles on their processing and applications. For the purpose of understanding mechanical changes within different temperature interval, dynamic structure transition of PA1010 was investigated by wide-angle X-ray diffractometer (WAXD) equipped with a hot stretching stage. During the process of the simultaneous thermal stretched, in addition to the Brill transition phenomenon, it was also accompanied by changes in crystallinity, orientation and tensile force. Both annealing and stretching can promote crystallization, in addition, stretching can also induce and destroy crystallization. With stretch ratios increasing, the crystallinity increases firstly, reaches the maximum when stretch ratio is 2.25 times and then decreases. The degree of orientation increase firstly but increase poorly after 2.50 times. The stretch force increase gradually too. The stretch force has a stronger ability than temperature to induce the PA1010 undergo the Brill transition. The presented results show that Brill transition is completed and the α-crystal structure completely transformed into γ-crystal structure when the stretch ratio is 2.50 times.

Phytofabrication of iron nanoparticles and their catalytic activity

Metallic nanoparticles that have photocatalytic activity can be synthesized using aqueous plant extracts. The aim of this study was to synthesize iron nanoparticles using Lantana trifolia extracts and to evaluate their ability to degrade Congo red dye. The nanoparticles were characterized using UV–Vis spectrophotometer (UV–Vis), Fourier transform infra-red spectrophotometer, wide angle X-ray diffractometer, dynamic light scattering, transmission electron microscopy (TEM), and thermal gravimetric analyzer to determine the functional groups, thermal properties, crystalline phases and diameter distribution of the particles. Cyclic voltammetry was used to evaluate the redox potential of the extracts while photocatalytic activity of the nanoparticles was evaluated using a UV–Vis spectrophotometer. Functional groups analysis revealed presence of secondary metabolites having OH and C=C groups while a redox potential of + 0.3 V was an indication that the extracts can reduce iron. The presence of sharp peaks at 2θ values of 19.87°, 20.22°, 22.88°, 28.81°, 32.73°, 35.32°, 38.45°, 40.23° and 41.08° correspond to cubic crystal system of iron nanoparticles while particle aggregation was observed on TEM micrographs which also indicated that they were less than 200 nm. In the presence of H2O2, the nanoparticles catalyzed degradation of Congo red dye in a first order reaction that was temperature dependent. In conclusion, secondary metabolites in L. trifolia can reduce metallic ion to iron nanoparticles which can degrade Congo red dye.

Synthesis and characterization of dialdehyde cellulose nanofibers from O. sativa husks

Periodate oxidation of cellulose breaks the C2–C3 bond of the glucose repeating units forming two vicinal aldehyde groups that are amenable to further reactions. In this article, effects of reaction conditions during the oxidation such as reaction time, oxidant concentration, and temperature on the aldehyde content were investigated and an optimized reaction condition identified. The synthesis of 2,3-dialdehyde cellulose (DAC) was confirmed by scanning electron microscopy, transmission electron microscopy (TEM), Fourier-transform infra-red spectroscopy (FT-IR), differential scanning calorimetry, thermal gravimetric analysis and wide-angle X-ray diffractometer (WXRD). Formation of dialdehyde cellulose (DAC) was confirmed by the appearance of carbonyl peak in FT-IR spectra while a decrease in crystallinity of the fibers as a result of oxidation was confirmed by WXRD. Morphological changes during oxidation were observed using SEM while the size of the fibers was confirmed by TEM, which showed the average length of the fibers decreased after oxidation as compared to native cellulose. Thermal degradation studies revealed that oxidation of cellulose decreased the thermal stability of the polymer as compared to native cellulose and was dependent on the aldehyde content. In conclusion, oxidation of native cellulose to dialdehyde cellulose had a profound effect on the thermal stability, degree of crystallinity, size and morphology of the polymer.

Influences of octamethylenedicarboxylic dibenzoylhydrazide on crystallization, melting behaviors, and properties of isotactic polypropylene

In this work, octamethylenedicarboxylic dibenzoylhydrazide (TMC-300) was used as a highly efficient α-phase nucleating agent for isotactic polypropylene (iPP) for the first time. The influences of TMC-300 on crystallization and melting behaviors as well as mechanical and thermal properties of iPP were analyzed by differential scanning calorimeter, polarizing optical microscope, wide-angle X-ray diffractometer, and universal mechanical tests. The results reflected that TMC-300 had excellent nucleation effect and that 0.20 wt% was the optimal addition concentration for iPP. Compared to those of neat iPP, the crystallization temperature, the bending modulus, and the heat distortion temperature of nucleated iPP was increased by 7.10 °C, 14.3% and 18.30 °C, respectively, at 0.2 wt% addition amount of TMC-300. In addition, the spherulite size of iPP after addition of TMC-300 was also reduced obviously.

Effect of Carboxylic Acid Nucleating Agent on Crystallization and Mechanical Properties of PLA/PBS Blends

Poly(lactic acid) (PLA)/poly(butylene succinate) (PBS) blends were prepared using a carboxylic acid salt as nucleating agent (NA). The effect of NA on the crystallization kinetics of PLA and PLA/PBS blend was investigated using a differential scanning calorimeter, a polarized optical microscope and a wideangle X-ray diffractometer. The crystallization rate of PLA component in PLA/PBS blends is increased effectively by NA through fast nucleation and growth rate of PLA α'-form crystal, which is confirmed by isothermal crystallization behavior of PLA/PBA/NA composites. The isothermal crystallization results also show that the incorporation of NA induces heterogeneous nucleation mechanism in PLA component. The increased number of crystal nuclei hinders the increase of average grain size of PLA component in composites but contributes to a higher crystallinity of both PLA and PBS components in PLA/PBS blends. Finally, the mechanical properties and dynamic mechanical properties of PLA/PBS/NA composites are improved because of the increased crystallinity, which are superior to that of PLA/PBS blend.

A facile route for the preparation of proton exchange membranes using sulfonated side chain graphite oxides and crosslinked sodium alginate for fuel cell

Functionalized graphite oxide was prepared and subjected to sulfonation via a simple procedure in the presence of 1,4-butane sultone (BS) and sodium dodecylbenzenesulfonate (SDBS). The resulting sulfonated graphite oxides were incorporated into polystyrene sulfonicacid-co-maleic acid (PSSA-MA) crosslinked sodium alginate in different mass% to enhance the water uptake, mechanical stability and proton conductivity of the membranes. The physico-chemical changes in the resulting proton exchange membranes were investigated using Fourier transform infrared spectrometer (FT-IR), wide-angle X-ray diffractometer (WAXD), scanning electron microscope (SEM), differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA). The proton conductivity of the synthesized composite membranes was measured using a high precession impedance analyzer. Among the developed proton exchange membranes (PEMs), membranes containing 16 mass% of graphite oxide sulfonated with BS and SDBS respectively exhibited the highest proton conductivity of 0.133 and 0.145 S/cm at 80 °C. The ion exchange capacity (IEC) of these membranes was found to be 1.40 and 1.52 meq/g, respectively. The performance of the membranes was evaluated using fuel cell workstation at 80 °C. Among the membranes developed, 16 mass% of BS-GO and SDBS-GO incorporated membranes demonstrated the power density of 0.39 and 0.42 W/cm2, respectively. These properties are superior to the commercially available Nafion® 117 membrane. Thus, these proton exchange membranes developed here could be employed for fuel cell applications.

The relationship between side chain isomerism of aliphatic C4 substituted 1,3,5-benzenetricarboxylamides and nucleation effects in isotactic polypropylene

the relationship between side chain isomerism of aliphatic C4 substituted 1,3,5-benzenetricarboxylamides (BTA-Rs, 1,3,5-benzenetricarboxylic acid tris(tert-butylamide) (BTA-TB), 1,3,5-benzenetricarboxylic acid tris(iso-butylamide) (BTA-IB) and 1,3,5-benzenetricarboxylic acid tris(n-butylamide) (BTA-NB)) and nucleation effects in iPP were investigated by differential scanning calorimeter (DSC), polarizing optical microscope (POM) and wide-angle X-ray diffractometer (WXRD). The results showed BTA-TB, BTA-NB and BTA-IB were efficient nucleating agents for iPP, and all of them induced formation of α-form spherulites and increased the crystallization peak temperature of iPP dramatically. However, BTA-NB had dual nucleation abilities for both α- and β-form crystals and induced iPP to form β-form spherulites at high content. The optimum contents of BTA-TB, BTA-NB and BTA-IB in iPP were 0.25wt%, 0.3wt% and 0.15wt%, respectively. Under the optimum content the crystallization peak temperature of iPP nucleated with BTA-TB, BTA-NB and BTA-IB increased from 122.5°C of neat iPP to 130.4°C, 132.1°C and 130.1°C, respectively.

Effects of molecular architecture on the rheological and physical properties of polycaprolactone

The molecular modification of polycaprolactone (PCL) is of great importance for producing optimum physical properties for a given application. Linear polycaprolactone (L-PCL) and 4-arm star polycaprolactone (4-PCL) with similar molecular weights were prepared, and their rheological, thermal, and morphological properties were investigated in relation to their molecular architecture. In dilute solutions, L-PCL exhibited a higher intrinsic viscosity than 4-PCL. In the molten state, the former displayed a higher viscosity and greater temperature dependence of molecular relaxation time than the latter. DSC thermograms showed that molecular architecture had little effect on the melting/crystallization temperature and crystallinity. Thermogravimetric analysis indicated that the introduction of a branched structure deteriorated the thermal stability of PCL, which might be associated with the increased number of hydroxyl end groups in the polymer chains. In isothermal crystallization under shear at two different temperatures, 4-PCL exhibited longer crystallization times than L-PCL. A more notable difference in dynamic crystallization behavior caused by the chemical architecture was observed at 40°C than at 45°C. Examination with a wide angle X-ray diffractometer revealed that shear and temperature applied during isothermal crystallization, as well as chemical architecture, had little effect on the crystal structure.

Enzymatic degradation of poly(butylene succinate) by cutinase cloned from Fusarium solani

A gene encoding cutinase from Fusarium solani was cloned and overexpressed in Pichia pastoris. The recombinant cutinase with a molecular weight of 24 kDa was then purified to homogeneity. The enzyme presents degradation capacity for poly(butylene succinate) (PBS) and exhibits the optimum pH and temperature of 8.0 and 50 °C, respectively. Enzyme activity is enhanced by K+ and Na+ and inhibited by Zn2+, Fe2+, Mn2+, and Co2+. The inhibitions of different chemicals on recombinant enzyme activity were examined. EDTA and β-mercaptoethanol exert significant inhibitory effect. The degradation of PBS films in the presence of the recombinant enzyme was further studied. Results showed that enzymatic degradation is a rapid process, and the PBS films were degraded completely after approximately 6 h. The characteristics of PBS films after degradation were analyzed. With the extension of degradation time, the surfaces of PBS films became rougher and holes appeared with a gradually increasing trend. Differential scanning calorimetry and scanning electron microscopy analyses revealed that both amorphous and crystalline regions of PBS were degraded by the recombinant enzyme. Wide-angle X-ray diffractometer also indicated the crystallinity of PBS has a gradual downward trend with the extension of degradation time. Gel permeation chromatography showed the molecular weight of PBS has no obvious change before and after degradation.

Surface Chemical Treatments of Jute Fiber for High Value Composite Uses

In order to confer hydrophobicity, higher mechanical and thermal properties, jute fiber has been chemically modified by means of NaClO2 bleaching, acrylonitrile (AN) grafting and diphenylmethanediisocyanate (DPMIC) treatment. The extent of modification reaction is evaluated by FTIR measurement. Morphologies and crystalline index of jute fibers are investigated using scanning electron microscopy (SEM) and wide angle X-ray diffractometer (WAXD). A significant variation in fibre surface occurred by chemical treatments is clearly observed in SEM images. It has been found that tensile properties (tensile strength, extension at break and Young's modulus) are substantial improved by AN-grafting and DPMIC treatment. Based on findings of hydrophobicity, the DPMIC treated fiber has been showed better properties than other fibers. Chemical treatment also increases the thermal stability. The TG and DTA curves show two-stages of decomposition for all the fibres; first below 100°C indicating the moisture loss and the second between 320°C and 360°C due to major degradation of fibre.

Thermotropic liquid crystalline polyesters derived from bis-(4-hydroxybenzoyloxy)-2-methyl-1,4-benzene and aliphatic dicarboxylic acid chlorides

A series of thermotropic liquid crystalline polyesters derived from bis-(4-hydroxybenzoyloxy)-2- methyl-1,4-benzene (BHBOMB) and aliphatic dicarboxylic acid chlorides were investigated. All these polyesters were synthesized by interfacial polycondensation method and characterized by differential scanning calorimetry and wide-angle X-ray diffractometer. These polyesters consist of BHBOMB as a mesogenic diol and aliphatic diacid chlorides were used as flexible spacers. The length of oligomethylene units in polymer was varied from the trimethylene to the dodecamethylene groups. The transition temperatures and thermodynamic properties were studied for all these polymers. All these polyesters were soluble in chlorinated solvents such as chloroform, dichloromethane, dichloroethane, etc. More importantly, all these polyesters exhibited very large mesophase stability.

Synthesis and Characterization of Novel Processable and Flexible Polyimides Containing 3,6-Di(4-carboxyphenyl)pyromellitic Dianhydride

A series of six novel polyimides containing 3,6-di(4-carboxyphenyl)pyromellitic dianhydride were synthesized via two steps condensation method. Aromatic diamines monomers, 4-(4-aminophenoxy)-N-(4-(4-aminophenoxy)benzylidene)-3-chloroaniline (DA1), 4-(4-amino-3-methylphenoxy)-N-(4-(4-amino-3-methylphenoxy)benzylidene)-3-chloroaniline (DA2), 4-(4-amino-2-methylphenoxy)-N-(4-(4-amino-2-methylphenoxy)benzylidene)-3-chloroaniline (DA3) 4-(4-aminophenoxy)-N-(4-(4-aminophenoxy)benzylidene)-2-methylaniline (DA4), 4-(4-amino-3-methylphenoxy)-N-(4-(4-amino-3-methylphenoxy)benzylidene)-2-methylaniline (DA5), and 4-(4-amino-2-methylphenoxy)-N-(4-(4-amino-2-methylphenoxy)benzylidene)-2-methylaniline (DA6) were prepared and used to synthesize new polyimides by reaction with resynthesized 3,6-di(4-carboxyphenyl)pyromellitic dianhydride by using two-step condensation method. The inherent viscosities of polyimides range from 0.68–1.04 dL gm−1 and were soluble in polar solvents. Polyimides have excellent thermal stability by showing 10% weight loss temperature was above 450°C. Their glass transition temperatures lie in the range of 250–335°C. Wide-angle X-ray diffractometer investigations revealed the amorphous nature of polyimides. Therefore, these polymers can be a potential candidate as processable high performance polymeric materials.