Structure–thermomechanical property correlation of moisture cured poly(urethane-urea)/clay nanocomposite coatings

A series of poly(urethane-urea)/clay nanocomposite coatings were prepared by moisture curing of isophorone diisocyanate (IPDI) capped hydroxyl terminated polybutadiene (HTPB)/clay dispersions in a relative humidity (RH) of 50% at 25 °C. The curing progress was studied by periodic measurement of gel fraction of the coating samples. The studies revealed tortuosity effects of clay toward moisture diffusion, thus delaying the induction period of gelation, time for complete cure and rate of gel formation of the nanocomposite coatings. The clay platelets were found to be intercalated in the poly(urethane-urea) matrix, evidenced from wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Effects of nanoclay on state of the hard and soft segments were investigated by WAXD, differential scanning calorimetry (DSC), temperature modulated DSC (MDSC) and solid-state nuclear magnetic resonance spectroscopy (NMR). WAXD studies revealed unusually ordered hard segment morphology of the moisture cured poly(urethane-urea) and its nanocomposites. Slower soft segment dynamics upon clay addition was evident from concentration dependant broadening of the line widths of the NMR peaks, and decreasing reversible heat capacity changes at soft segment glass transition. The volume fraction of immobilized soft segments of the nanocomposites was determined from MDSC and was found to increase linearly with clay loading. The mechanical property analysis showed simultaneous reinforcement and toughening effect of nanoclay on the MCPU matrix. The increment in mechanical property of the nanocomposites varied proportionately with the volume fraction of immobilized soft segments.     

Copper removal during formation of corrosion resistant alkaline oxide coatings on Al–Cu–Mg alloys

The performance of corrosion resistant inorganic oxide coatings formed on Al–Cu–Mg alloys is often degraded by Cu enrichment that occurs during oxide formation. This is particularly true of coating processes conducted in basic solutions. A modification to an alkaline oxide coating process has been made that simultaneously eliminates Cu enrichment and forms a corrosion resistant coating. In this paper, the modified process is described and the resulting coating morphology, structure and composition are reported. Results from electrochemical and exposure corrosion tests show that useful gains in corrosion resistance are achieved. Cu removal during the modified process is rationalized using an argument based on the increase in Cu solubility that occurs in solutions with a pHgreater than the solubility minimum for Cu (9.8), and the effect of Cu complexing by carbonate.     

A crosslinked waterborne poly(urethane-urea) oligomer enables mechanically strong waterborne polyacrylate–poly(urethane-urea) hybrid films with superior film-forming ability

In this article, a crosslinked waterborne poly(urethane-urea) (WPUU) is synthesized based on the terminal aromatic amine polyether (DP-1000) and aliphatic isophorone diisocyanate. Then WPUU is compound with acrylate monomer by emulsion polymerization to produce waterborne polyacrylate–poly(urethane-urea) (WPUUA) hybrid emulsions. Compared with waterborne polyacrylate (WPA) film, the film-forming ability of WPUUA film is improved and the surface roughness R_a and R_q of WPUUA film decreases from 47.5 and 36.4 nm to 35.2 and 18.8 nm, respectively. Meanwhile, the mechanical properties of WPUUA films are significantly improved compared to WPA film. In addition, the performances of WPUUA hybrid films can be modified according to requirements by adjusting the molar ratio between DP-1000 and polyisocyanate. As a result, these WPUUA hybrid emulsions have great application potential in waterborne coatings and other fields.     

Corrosion resistant behaviour of PANI–metal bilayer coatings

The present work discusses on the corrosion resistant behaviour of polymer metal bilayer coatings, viz. polyaniline (PANI), polyaniline–nickel (PANI–Ni), nickel–polyaniline (Ni–PANI), polyaniline–zinc (PANI–Zn) and zinc–polyaniline (Zn–PANI). The coatings were synthesized by means of cyclic voltametric method. The coatings thus obtained were uniform in nature and highly adherent to the mild steel substrate. The effectiveness of the coatings in preventing corrosion was tested by electrochemical impedance studies (EIS) using Nyquist and Bode plots and potentiodynamic polarization studies as well. Among the various coatings synthesized, the PANI–Zn coating was found to offer the maximum protection, followed by PANI–Ni coatings. Metal–PANI coatings were found to offer the least resistance to corrosion. The coatings thus obtained were characterized by scanning electron microscopic (SEM) analysis and the results are discussed.     

DSC studies of poly(vinyl chloride)/poly(ε-caprolactone)/poly(ε-caprolactone)-b-poly(dimethylsiloxane) blends

Poly(vinyl chloride)/poly(ε-caprolactone)/poly(ε-caprolactone)-b-poly(dimethylsiloxane) [PVC/PCL/(PCL-b-PDMS)] blends were prepared by solvent casting from tetrahydrofuran. The content of PVC was kept constant (60 wt%); the PCL and PCL-b-PDMS contents were varied by replacing different amounts of PCL [0–20 wt% from the PVC/PCL (60/40) blend] with PCL-b-PDMS copolymer having different molecular weights of the PCL blocks. The thermal properties of prepared blends were investigated by differential scanning calorimetry in order to analyse miscibility (through glass transition temperature) and crystallinity. Differential scanning calorimetry analyses show that the PVC/PCL/PCL-b-PDMS blends are multi-phase materials which contain a PVC plasticized with PCL phase, a block copolymer PCL-b-PDMS phase (with crystalline and amorphous PCL and PDMS domains) and a PCL phase (preponderantly crystalline).     

Preparation of dendritic waterborne polyurethane-urea/Ni–Zn ferrite composite coatings and investigation of their microwave absorption properties

This study shows the preparation of microwave absorbing composite material by using Ni–Zn ferrite filler and dendritic waterborne polyurethane-urea (WPU) polymer as a matrix. Initially, waterborne polyurethane prepolymers were synthesized by using PEG1500 (WPU1) and PPG1000 (WPU2) polyols via prepolymer mixing process. Then, chain extended with water in the presence of hexamethylenetetramine (HMTA) as crosslinker. Then, 1/1 (w/w) amount of Ni–Zn ferrite was dispersed in the WPU polymer to be converted into a microwave absorbing composite coating (CWPU1 and CWPU2). Structural, mechanical and morphological properties were investigated. The microwave absorption measurements were performed by using transmission/reflection method via waveguide method in the frequency range of 8.2–12.4 GHz. Permittivity and permeability measurements were performed in the frequency range of 8.2–12.4 GHz. It has been found that CWPU1 which was prepared by using WPU1 polymer indicated broader microwave absorption between 9.4 and 11.7 GHz due to its dendritic structure. Besides, permittivity and permeability results indicated that CWPU1 and CWPU2 have distinctive magnetic properties.     

Preparation and properties of soapless poly(styrene–butyl acrylate–acrylic acid)/SiO2 composite emulsion

Soapless emulsion polymerization of styrene-butyl acrylate-acrylic acid was carried out using single or combined polymerizable emulsifiers, such as hydroxypropyl methacrylate sodium sulfate (HPMAS), sodium vinyl sulfate, and vinyl alkylphenol polyether sulfates (NRS-10), in the presence of colloidal nano-SiO₂ solution in order to obtain films with high degree of hardness and water-resistance. Monomer conversion, formation of coagulum, viscosity, particle size, size distribution, and surface tension of the emulsions, as well as the film properties, were determined and compared with those of an emulsion prepared with the conventional emulsifier sodium dodecyl sulfate and polyoxyethylene octylphenol ether. Emulsions prepared from a mixture of two polymerizable emulsifiers NRS-10 and HPMAS (1:1, weight ratio) have presented high monomer conversion, low coagulum, and small particle sizes. When the emulsifier level increased within a certain level, the monomer conversion increased but particles size decreased. Increased amounts of reactive emulsifiers led to low monomer conversion, large amount of coagulum and small particle sizes. With the increase of nano-SiO₂ the particle sizes and the viscosity of the emulsion also increased. The introduction of reactive emulsifiers improved the water-resistance of the resulting films, and the addition of nano-SiO₂ increased the hardness of the coatings. Under optimal conditions, the coatings made from emulsions produced from a combination of reactive emulsifiers such as NRS-10 and HPMAS (1:1, weight ratio) at 2?% level (based on monomer weight) exhibited remarkable hardness, adhesion force and water-resistance.     

The preparation and characteristics of poly(methyl methacrylate–methylacrylate acid)/nano-ZnO composite latex particles

In this work, poly(methyl methacrylate-co-methylacrylate acid)/ZnO (poly(MMA–MAA)/ZnO) composite latex particle was synthesized by three steps The first step was to synthesize poly(MMA–MAA) copolymer latex particles by soapless emulsion polymerization. Following the first step, the second step was to polymerize MMA, MAA and 3,3-(trimethoxysilyl) propyl methacrylate (MPS) in the presence of poly(MMA–MAA) seed latex particles to form the poly(MMA–MAA)/poly(MMA–MAA–MPS) core–shell latex particles. In the third step, the poly(MMA–MAA)/poly(MMA–MAA–MPS) latex particles reacted with ZnO nanoparticles, which were synthesized by a traditional sol gel method, to form the polymer/inorganic poly(MMA–MAA)/poly(MMA–MAA–MPS)/ZnO composite latex. In this study, MPS with silanol groups essentially was used as the coupling agent to couple with ZnO nanoparticles, while the results of the study showed that there was not covalent bond existed between ZnO particles and polymer latex. The ZnO particles were adsorbed on the surface of polymer latex by electrostatic interaction. Besides, the linear poly(MMA–MAA)/crosslinking poly(MMA–MAA–MPS) core–shell latex particles which were synthesized in the second step were heated in the presence of ammonia to form the hollow poly(MMA–MAA–MPS) latex particles. The factors of heating time and concentration of crosslinking agent significantly influenced the morphology of hollow poly(MMA–MAA–MPS) latex particles.     

Structure–property evolution of poly(ethylene terephthalate)/poly(trimethylene terephthalate) side-by-side self-crimp filament

To investigate the microstructure and mechanical properties of self-crimping two-component side-by-side bicomponent filament, this paper focuses on systematically investigating the structure–property evolution of poly(ethylene terephthalate) (PET)/poly(trimethylene terephthalate) (PTT) side-by-side bicomponent filament prepared via melt spinning with various component ratios, drawing and heating treatment. The investigation was operated upon the combination of morphology analysis, thermal analysis, crystallization, and orientation analysis. The variation of cross section and curl-morphology, crystallization, and microstructures mainly containing lamellar and microfibrillar crystals as well as their effects on the mechanical and self-crimping properties were discussed. As the draft ratio (DR) increases, the crystallinity, sonic orientation factor, tensile strength, and crimp-recovery rate of the filaments were increased. The sonic orientation factor in the crystalline region decreases from 0.923 to 0.777 but increases from 0.677 to 0.903 in the amorphous region. In contrast to the variation of the DR, heating temperature has a limited effect on the tensile strength of the PET/PTT hybrid filaments. Crimp-recovery rate, however, first increases to 11.8 and then decreases to 9.8 with an increasing heating temperature from 144 to 168°C. Most of these behaviors have been attributed to changes in the ratio of contractile stress for both PTT and PET components, originating from microstructural evolution in hybrid filaments, including crystal growth, breakage, deflection, and deformation of chains along the axial direction. As a summary, an interpretive diagrammatic sketch has been proposed to clarify the structure–property relationships of the commercial PET/PTT filaments.     

Preparation of clay–poly(glycidyl methacrylate) composite support for immobilization of cellulase

A composite material was synthesized by grafting of glycidyl methacrylate onto clay using surface initiation atom transfer radical polymerization (SI-ATRP) technique. Epoxy group of the grafted p(GMA) chains was reacted with hexamethylenediamine (HMDA). The composite material was characterized using scanning electron microscopy (SEM) and FTIR. Cellulase from Trichoderma reesei was immobilized on the aminated composite particles via adsorption and covalent binding methods. The amounts of adsorbed enzyme on the aminated composite particles were 43.4 mg/g. The recovered activities of the adsorbed and covalently immobilized cellulase were found to be 87.7% and 73.2% for the substrate, carboxymethyl cellulose (CMC, 1.0 g/L). The pH stabilities and thermo-stabilities, repeated use and storage stabilities of both immobilized cellulase preparations were evaluated. The immobilized cellulase preparations have better stabilities and higher retained activities with respect to pH, temperature and storage than those of the free enzyme. Operational stability of the covalently immobilized cellulase was tested in a continuous flow system, and the activity loss was about 4% at the end of 48 h operation period.     

Synthesis and characterization of a novel amphiphilic poly (ethylene glycol)–poly (ε-caprolactone) graft copolymers

A series of amphiphilic graft copolymers PEO-g-PCL with different poly (ε-caprolactone) (PCL) molecular weight were successfully synthesized by a combination of anionic ring-opening polymerization (AROP) and coordination-insertion ring-opening polymerization. The linear PEO was produced by AROP of ethylene oxide (EO) and ethoxyethyl glycidyl ether initiated by 2-(2-methoxyethoxy) ethoxide potassium, and the hydroxyl groups on the backbone were deprotected after hydrolysis. The ring-opening polymerization of CL was initiated using the linear poly (ethylene oxide) (PEO) with hydroxyl group on repeated monomer as macroinitiator and Sn(Oct)₂ as catalyst, then amphiphilic graft copolymers PEO-g-PCL were obtained. By changing the ratio of monomer and macroinitiator, a series of PEO-g-PCL with well-defined structure, molecular weight control, and narrow molecular weight distribution were prepared. The expected intermediates and final products were confirmed by ¹H NMR and GPC analyzes. In addition, these amphiphilic graft copolymers could form spherical aggregates in aqueous solution by self-assemble, which were characterized by transmission electron microscopy, and the critical micelle concentration values of graft copolymers PEO-g-PCL were also examined in this article.     

Synthesis and characteristics of poly(methacrylic acid–co–N-isopropylacrylamide)/Nano ZnO thermosensitive composite hollow latex particles

In this work, the poly(methacrylic acid–co–N-isopropylacrylamide)/Nano ZnO thermosensitive composite hollow latex particles was synthesized by three processes. The first process was to synthesize the poly(methyl methacrylate-co- methacrylic acid) (poly(MMA–MAA)) copolymer latex particles by the method of soapless emulsion polymerization. The second process was to polymerize MAA, N-isopropylacrylamide (NIPAAm) and N,N′-Methylenebisacrylamide (MBA) in the presence of poly(MMA–MAA) latex particles to form the linear poly(MMA–MAA)/crosslinking poly(MAA-NIPAAm) core–shell latex particles, and then the core–shell latex particles were heated in the presence of ammonia solution to form the poly(MAA-NIPAAm) thermosensitive hollow latex particles. In the third process, the poly(MAA-NIPAAm) hollow latex particles reacted with ZnO nanoparticles to form the poly(MAA-NIPAAm)/ZnO thermosensitive composite hollow latex particles on which the ZnO nanoparticles were adsorbed. Besides, a novel process was used to synthesize the poly(MAA-NIPAAm)/ZnO composite latex particles in which the ZnO nanoparticles were encapsulated. The effects of various variables on the morphology of poly(MAA-NIPAAm)/ZnO composite hollow latex particle were studied.     

Application of artificial neural networks to predict corrosion behavior of Ni–SiC composite coatings deposited by ultrasonic electrodeposition

A feed-forward, multilayer perceptron artificial neural network (ANN) model with eight hidden layers and 12 neurons was used to predict the corrosion behavior of Ni–SiC composite coatings deposited by ultrasonic electrodeposition. The effect of process parameters, namely, ultrasonic power, SiC particle concentration, and current density, on the weight losses of Ni–SiC composite coatings was investigated. The grain sizes of Ni and SiC were determined by using X-ray diffraction (XRD) and scanning probe microscopy (SPM). Results indicate that ultrasonic power, SiC particle concentration, and current density have significant effects on the weight losses of Ni–SiC composite coatings. The ANN model, which has a mean square error of approximately 3.35%, can effectively predict the corrosion behavior of Ni–SiC composite coatings. The following optimum conditions for depositing Ni–SiC composite coatings were determined on the basis of the lowest weight loss of Ni–SiC deposits: ultrasonic power of 250 W, SiC particle concentration of 8 g/l, and current density of 4 A/dm². XRD and SPM results demonstrate that the average grain sizes of Ni and SiC in the Ni–SiC composite coating are 90 and 70 nm, respectively.     

Polyoligomeric silsesquioxane (POSS)–hydrogenated polybutadiene polyurethane coatings for corrosion inhibition of AA2024

A series of coatings were developed that help prevent corrosion of aluminum alloy 2024 (AA2024). The coatings were based on an aliphatic polyurethane–polyoligomeric silsesquioxane (PU–POSS) resin. The materials were selected to exhibit a high level of hydrophobicity, which is expected to increase the moisture barrier properties, and thereby improve corrosion prevention. In addition, corrosion inhibitors (free molecules or encapsulated) were introduced into the coatings to improve corrosion resistance. The performance of the coatings was quantified using electrochemical impedance spectroscopy (EIS) and salt fog testing. Results from various formulations show that the hardness of the coating can be controlled by adjusting the ratio of POSS to hydrogenated hydroxyl terminated polybutadiene in the formulation. The coatings also had remarkable barrier properties, fast curing, and very high adhesion to the treated AA2024 substrate, all of which are expected to improve the anti-corrosion properties of the coatings. The best corrosion protection of AA2024 was observed in a transparent 10 μm thick PU–POSS bilayer coating that contained a mixture of sodium-2-mercaptobenzothiazole (i.e., NACAP) and benzotriazole-laden hydrotalcite. It was found that only certain corrosion inhibitors (free molecules or encapsulated) improve the anti-corrosion properties of the coating, whereas other corrosion inhibitors may actually degrade the coating performance.     

Effect of pH and carbon nanotube content on the corrosion behavior of electrophoretically deposited chitosan–hydroxyapatite–carbon nanotube composite coatings

In the first stage, chitosan (CH)–hydroxyapatite (HA)-multiwalled carbon nanotube (MWCNT) composite coatings were synthesized by electrophoretic deposition technique (EPD) on 316L stainless steel substrates at different levels of pH and characterized by X-ray diffraction (XRD), Raman spectroscopy, FTIR and field emission scanning electron microscopy (FESEM). A smooth distribution of HA and MWCNT particles in a chitosan matrix with strong interfacial bonding was obtained. In the next stage, effects of pH and MWCNT content of the suspension on the corrosion behavior and deposition mechanism were studied. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) curves revealed that increasing pH level of the suspension increases the corrosion protection properties of the deposited composite coating in simulated body fluid (SBF). Furthermore, Nyquist plots showed that increasing MWCNT content of the suspension resulted in higher amounts of R_p, but because of the capillary properties of MWCNTs and degradability of the chitosan matrix, corrosion protection level of the coatings containing HA–CH–MWCNT was lower than those of coatings containing solely HA–CH. Amperometric curves in different pH levels of the suspension revealed that the system is diffusion controlled at elevated pH values.     

Multilayered polypyrrole–SiO2 composite coatings for functionalization of stainless steel: Characterization and corrosion protection behavior

Two different multilayered composite polypyrrole/SiO₂ coatings were synthesized on 304 stainless steel. Electrochemical and electrophoretic depositions were used to grow polypyrrole and SiO₂ layers, respectively. Coatings were characterized by glow discharge optical emission spectroscopy to observe repartition of elements within different layers, by scanning electron microscopy to observe surface morphology and by electrochemistry to investigate corrosion protection behavior. The electrophoretic approach enables good incorporation of SiO₂ particles. This incorporation was more extensive and more homogeneous than for coatings obtained with the mixing method related in previous works. Moreover, incorporation and repartition of SiO₂ particles are greatly enhanced when the silica layer is grown directly on the steel surface. Corrosion protection of the stainless steel substrate was improved when multilayered composite polypyrrole/SiO₂ coatings were used.     

Enhanced calcium–magnesium–aluminosilicate (CMAS) resistance of GdAlO3 (GAP) for composite thermal barrier coatings

The impact of calcium–magnesium–alumino-silicate (CMAS) degradation is a critical factor for development of new thermal and environmental barrier coatings. Several methods of preventing damage have been explored in the literature, with formation of an infiltration inhibiting reaction layer generally given the most attention. Gd₂Zr₂O₇ (GZO) exemplifies this reaction with the rapid precipitation of apatite when in contact with CMAS. The present study compares the CMAS behavior of GZO to an alternative thermal barrier coating (TBC) material, GdAlO₃ (GAP), which possesses high temperature phase stability through its melting point as well as a significantly higher toughness compared with GZO. The UCSB laboratory CMAS (35CaO–10MgO–7Al₂O₃–48SiO₂) was utilized to explore equilibrium behavior with 50:50 mol% TBC:CMAS ratios at 1200, 1300, and 1400°C for various times. In addition, 8 and 35 mg/cm² CMAS surface exposures were performed at 1425°C on dense pellets of each material to evaluate the infiltration and reaction in a more dynamic test. In the equilibrium tests, it was found that GAP appears to dissolve slower than GZO while producing an equivalent or higher amount of pore blocking apatite. In addition, GAP induces the intrinsic crystallization of the CMAS into a gehlenite phase, due in part to the participation of the Al₂O₃ from GAP. In surface exposures, GAP experienced a substantially thinner reaction zone compared with GZO after 10 h (87 ± 10 vs. 138 ± 4 μm) and a lack of strong sensitivity to CMAS loading when tested at 35 mg/cm² after 10 h (85 ± 13 versus 246 ± 10 μm). The smaller reaction zone, loading agnostic behavior, and intrinsic crystallization of the glass suggest this material warrants further evaluation as a potential CMAS barrier and inclusion into composite TBCs.     

Development of an ionic polymer–metal composite stepper motor using a novel actuator model

A novel ionic polymer–metal composite (IPMC) actuated stepper motor was developed in order to demonstrate an innovative design process for complete IPMC systems. The motor was developed by utilizing a novel model for IPMC actuators integrated with the complete mechanical model of the motor. The dynamic, nonlinear IPMC model can accurately predict the displacement and force actuation in air for a large range of input voltages as well as accounting for interactions with mechanical systems and external loads. By integrating this geometrically scalable IPMC model with a mechanical model of the motor mechanism an appropriate size IPMC strip has been chosen to achieve the required motor specifications. The entire integrated system has been simulated and its performance verified. The system has been built and the experimental results validated to show that the motor works as simulated and can indeed achieve continuous 360° rotation, similar to conventional motors. This has proven that the model is an indispensable design tool for integrated IPMC actuators into real systems. This newly developed system has demonstrated the complete design process for smart material actuator systems, representing a large step forward and aiding in the progression of IPMCs towards wide acceptance as replacements for traditional actuators.     

A novel foam-like silane modified alumina scaffold coated with nano-hydroxyapatite–poly(ε-caprolactone fumarate) composite layer

Although alumina scaffolds with biodegradable polymer coating can overcome the limitations of conventional ceramic bone substitutes, the bioactivity potential of these scaffolds needs to be enhanced. In this study, the macroporous alumina scaffolds with the defined pore-channel interconnectivity were successfully prepared by the foam replication method. The average pore size of the scaffolds was in the range 200–900 μm with around 82% porosity. The average Young's modulus of alumina scaffolds was 2.8 GPa. Coating of nano-hydroxyapatite (nano-HA) in poly(ε-caprolactone fumarate) (PCLF) as a carrier on the surface of alumina scaffold was performed. The nano-HA powder was synthesized successfully by the sol–gel method. The crystallite and particle sizes of HA powders were in nano range and confirmed by the Scherrer equation from X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The PCLF was synthesized and characterized by fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). In order to make a chemical link between the alumina scaffolds and the coating, a silane coupling agent was used. The results showed that using of 1 g Methacryloxypropyl trimethoxysilane in 100 g solvent is sufficient for making a thin interface layer between the scaffold and the polymer. The coating process was performed by immersion of scaffolds in the solutions with different percents of nano-HA. The morphology and chemical structure of the coated scaffolds were investigated by SEM and FTIR. SEM images demonstrated that the scaffolds were constituted of interconnected and homogeneously distributed pores. Also, HA distribution and agglomerates on the surface of scaffolds were enhanced by increasing the nano-HA percent in the coating solutions.     

A facile and green method for the production of novel and potentially biocompatible poly(amide-imide)/ZrO2–poly(vinyl alcohol) nanocomposites containing trimellitylimido-l-leucine linkages

We have reported the synthesis of nanocomposites (NCs) based on chiral poly(amide-imide) (PAI) and modified zirconium nanoparticles (ZrO₂ NPs) with poly(vinyl alcohol) (PVA). The optically active PAI was prepared under the green condition via the direct polycondensation of biocompatible trimellitylimido-l-leucine diacid and 4,4′-diaminediphenylsulfone in the presence of tetrabutylammonium bromide and triphenyl phosphite as the green solvent and the activating agents. NPs, due to a high surface to volume ratio, have a great tendency to agglomerate in the polymer matrix. So, at first, the surface of ZrO₂ NPs was modified with the PVA as the biodegradable and biocompatible polymer. Afterward, the modified NPs were added into the PAI matrix in the ethanol solution under ultrasonic irradiations. The obtained PAI/ZrO₂–PVA NCs (PZ–PNC)s were characterized by various techniques. The Fourier transform infrared proved the formation of PZ–PNCs. Field emission-scanning electron microscopy exhibited that ZrO₂ NPs had good dispersion in the PAI matrix, and transmission electron microscopy indicated that ZrO₂ NPs were coated by a nanometer-thick layer of PVA that was about 10 nm. X-ray diffraction analysis showed that the ZrO₂ NPs retained their crystalline structure after they were added in the PAI matrix. Thermogravimetric analysis illustrated that the prepared PZ–PNCs had a better thermal stability than the neat PAI.