Modification of conducting arylidene copolymers by formation of inclusion complexes: synthesis, characterization, and applications as highly corrosion inhibitors for mild steel

Modifying the metal surface is one solution to the industry's growing corrosion problem. Thus, via threading approach and insertion of copolymers (CoP5-7) containing polyarylidenes through the internal cavity beta-cyclodextrin β-CD, novel pseudopolyrotaxanes copolymers (PC5-7) are developed, resulting in mild steel corrosion inhibition. Inhibitors of corrosion based on β-CD molecules adsorb strongly to metal surfaces because of their many polar groups, adsorption centers, many linkages of side chains, and benzene rings. The corrosion inhibition efficiencies IE % statistics have been revised via the Tafel polarization method and Spectroscopy based on the electrochemical impedance (EIS), with PC7 achieving the highest 99.93% in 1.0 M H₂SO₄; they are mixed-type inhibitors. The chemical composition of the resulting PCs is determined with Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) is utilized to examine the morphological structure of the produced polymers, and X-ray diffraction is employed to identify crystallinity. Encapsulating CoP5-7 with β-CD changes the morphological structures and increases the generated PCs' crystallinity. The thermal stability of PCs is studied, indicating the presence of these CoPs within the β-CD cavities enhances their thermal stability. This research will be a stepping stone for developing high-efficiency anti-corrosion coatings and various industrial applications.

Construction novel polybenzoxazine coatings exhibiting corrosion protection of mild steel at different concentrations in a seawater solution

In this work, a new and effective polymeric coating is used to improve mild steel's corrosion resistance. The coating incorporates a Schiff base moiety into a benzoxazine (BZ) precursor, resulting in improved protection against corrosion. The SF-Tol-BZ polymerization behavior and thermal properties were studied using differential scanning calorimetry (DSC) and thermalgravimetric analysis (TGA), respectively, at different curing temperatures. The poly(SF-Tol-BZ) cured at 240 °C had a Td10 value of 604 °C and a Tg of 225 °C. The efficacy of poly(SF-Tol-BZ) coatings in protecting mild steel (MS) from corrosion in a NaCl (3.5%) solution at room temperature was evaluated using various corrosion measurements, including open circuit potential (OCP), and electrochemical impedance spectroscopy (EIS). The results showed that increasing the poly(SF-Tol-BZ) concentration led to a corresponding increase in its protective efficiency, reaching a maximum of 92% at a concentration of 300 g/L. The coatings also exhibited a 24-fold increase in Rct values and a one-order-of-magnitude reduction in CPE compared to the bare mild steel. Finally, the poly(SF-Tol-BZ) precursors demonstrated a CO2 uptake of 23 mg g-1 (measured at 298 K).

Construction of novel polybenzoxazine coating precursor exhibiting excellent anti-corrosion performance through monomer design

In this study, we utilized salicylaldehyde (SA) and p-toluidine (Tol-NH₂) to synthesize 2-(Z)[(4-methylphenyl)imino]methylphenol (SA-Tol-SF), which was then reduced to 2-[(4-methylphenyl)amino]methylphenol, producing SA-Tol-NH. SA-Tol-NH was further reacted with formaldehyde to create SA-Tol-BZ monomer. Poly(SA-Tol-BZ) was produced by thermally curing it at 210 °C, after synthesizing it from SA-Tol-BZ. The chemical structure of SA-Tol-BZ was analyzed using various analytical techniques such as FT-IR, ¹H NMR spectroscopy, and ¹³C NMR spectroscopy TGA, SEM, DSC, and X-ray analyses. Afterward, we applied the obtained poly(SA-Tol-BZ) onto mild steel (MS) using thermal curing and spray coating techniques. To examine the anticorrosion attributes of MS coated with poly(SA-Tol-BZ), electrochemical characterization was employed. The study proved that poly(SA-Tol-BZ) coating had a high level of effectiveness in preventing corrosion on MS, with an efficacy of 96.52%, and also exhibited hydrophobic properties.

Synthesis, characterization and protective efficiency of novel polybenzoxazine precursor as an anticorrosive coating for mild steel

In this study, 2-[(E)-(hexylimino)methyl] phenol (SA-Hex-SF) was synthesized by adding salicylaldehyde (SA) and n-hexylamine (Hex-NH₂), which was subsequently reduced by sodium borohydride to produce 2-[(hexylamino)methyl] phenol (SA-Hex-NH). Finally, the SA-Hex-NH reacted with formaldehyde to give a benzoxazine monomer (SA-Hex-BZ). Then, the monomer was thermally polymerized at 210 °C to produce the poly(SA-Hex-BZ). The chemical composition of SA-Hex-BZ was examined using FT-IR, ¹H, and ¹³C NMR spectroscopy. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray Diffraction (XRD), respectively, were used to examine the thermal behavior, surface morphology, and crystallinity of the SA-Hex-BZ and its PBZ polymer. Mild steel (MS) was coated by poly(SA-Hex-BZ) which was quickly prepared using spray coating and thermal curing techniques (MS). Finally, the electrochemical tests were used to evaluate the poly(SA-Hex-BZ)-coating on MS as anti-corrosion capabilities. According to this study, the poly(SA-Hex-BZ) coating was hydrophobic, and corrosion efficiency reached 91.7%.

Synthesis, characterization and application of high adsorption performance of novel 1,4-polyketone

This study aims to develop an alternating polyketone containing cationic groups in one and four alternating positions for increased functionality. A novel polyarylidene ketone was synthesized using simple condensation polymerization of terephthaldehyde and 2,5-hexane dione (PAK) The physicochemical properties of the resulting polymer were evaluated using Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, UV-Visible absorbance, fluorescence, and SEM investigations. The findings show that the polymer is amorphous, has good thermal stability, and emits red light. It can also be used as a dye adsorbent in aqueous solutions, with high selectivity for the cationic dye methylene blue (MB). The adsorbent efficiency of PAK was measured as a function of pH, dosage, and initial dye concentration; the greatest dye removal of 96 % was obtained at pH 10, 50 mg dosage, and initial dye concentration of 20 ppm. Kinetics and isotherms were studied, showing that the pseudo-second-order model described kinetic data better than Freundlich and Langmuir and revealed a satisfactory chemisorption process. This study suggests that PAK can purify MB dyeing wastewater, remove Zn²⁺, Cu²⁺, Ni²⁺, Co²⁺, Cd²⁺, Fe³⁺ metal ions well, and is selective for Fe³⁺ and Cu²⁺; ion adsorption is chelating-based.

El-Bery3. High adsorption performance of novel 1,4-polyketone: synthesis, characterization, and removal of pollutants.. [DOI: 10.21203/rs.3.rs-1757708/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

This research aims to create an alternating polyketone with the advantage of having its cationic groups in one and four alternating places for increased functionality. Simple condensation polymerization between terephthaldehyde and 2,5-hexane dione yielded a new polyarylidene ketone (PAK). Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction, UV-Visible absorbance, fluorescence, and SEM studies were used to assess the physicochemical properties of the resultant polymer. The results demonstrate that the polymer is amorphous, has good thermal stability, and emits a red color. It can also be utilized as a dye adsorbent in an aqueous solution, with remarkable adsorption selectivity for the cationic dye methylene blue (MB). The effectiveness of PAK as an adsorbent was calculated as a function of pH, dosage, and initial dye concentration; the highest dye removal percentage of 96% was achieved at pH 10, 50 mg dosage and initial dye concentration of 20 ppm. The study of kinetics and isotherms was also carried out. The pseudo-second-order model was more adapted to the kinetic data, while the Freundlich and Langmuir models were better suited to the PAK equilibrium data. According to the kinetics and isotherms analyses, the adsorption behavior was a favorable chemisorption process. The findings of this study suggest that PAK could be used as an adsorption filter for MB dyeing wastewater decolorization. It also has excellent metal ion removal capabilities with various metals (Zn2+, Cu2+, Ni2+, Co2+, Cd2+, and Fe3+). PAK is selective for Fe (III) and Cu (II); the polymers' ion adsorption is not based on ion exchange but on chelating process.

Thermally stable hybrid polyarylidene(azomethine-ether)s polymers (PAAP): an ultrasensitive arsenic(III) sensor approach

A new category of thermally stable hybrid polyarylidene(azomethine-ether)s and copolyarylidene(azomethine-ether)s (PAAP) based on diarylidenecycloalkanones has been synthesized using solution polycondensation method. For potential cationic sensor development, a thin layer of PAAP onto a flat glassy carbon electrode (GCE, surface area: 0.0316 cm²) was prepared with conducting nafion (5%) coating agent to fabricate a sensitive and selective arsenic (III) [As³⁺] ion in short response time in neutral buffer system. The fabricated cationic sensor was measured the analytical performances such as higher sensitivity, linear dynamic range, detection limit, reproducibility, and long-term stability towards As³⁺ ions. The sensitivity and detection limit were calculated as 2.714 μAμM^-1cm^-2 and 6.8 ± 0.1 nM (SNR of 3; 3N/S) respectively from the calibration curve. This novel approach can be initiated a well-organized route of an efficient development of heavy selective arsenic sensor for hazardous pollutants in biological, environmental, and health care fields. Real sample analysis for various environmental sample was performed with PAAP-modified-GCE.

New polymer syntheses II--linear unsaturated polyesters containing azo groups*

Linear unsaturated polyesters, characterized by the presence along the polymer chain of azo groups between aromatic rings, have been prepared by reacting 3,5-bis(p-hydroxybenzylidene)isopropyl piperidinone (BHIP, I) or 3,5-divanillylidene isopropylpiperidinone (DVIP, It) with 4,4'-azodibenzoyl chloride (III) and 3,3'-azodibenzoyl chloride (IV) using the interfacial polycondensation method. The polymers were characterized by elemental analyses. IR spectroscopy, solubility and viscomnetry. The thermal properties of the polymers were evaluated by thermogravimetric analysis (TGA) and correlated to their structural units. Al] the polymers dissolved readily in concentrated H2S04 or o-cresol. X-ray analysis of the polymers showed some degree of crystallinity in polymers VI and VII. Moreover, the UV-visible spectra of certain polymers were measured in NMP or in dimethyl suiphoxide (DMSO)solutions and showed characteristic absorption bands at 412 and 432 nrn due to n-7r* transition.

New Polymer Synthesis VI: Synthesis, Characterization and Morphology of New Polyoxaloylesters Derived from Diarylidenecycloalkanones

New polyoxaloylesters have been synthesized via interfacial polycondensation of oxaloyl chloride with 2,5-bis( p-hydroxybenzylidene)cyclopentanone I, 2,5-divanillylidenecyclopentanone II, 2,6-bis( p-hydroxybenzylidene)cyclohexanone III, 2,6-divanillylidenecyclohexanone IV, and 2,7-bis( p-hydroxybenzylidene)cycloheptanone V at ambient temperature. These polyoxaloylesters were characterized by elemental analysis, IR spectra, 1H NMR, solubility measurements, viscometry, DSC and thermogravimetric analyses. The crystallinity of the polymers was examined by x-ray analysis. The morphology of a high-performance polyoxaloylester, namely poly[oxyoxaloyloxy- p-phenylenemethylidyne (2-oxo-1,3-cyclohexanediylidene)methylidyne- p-phenylene], has been investigated by scanning electron microscopy. Electrical conductivity is in the range 10−11 -10−13Ω−1 cm−1.

New Polymer Syntheses IV. Synthesis and Characterization of New Polyamides Containing Bis-Benzthiazolyl Sulphone Units in the Main Chain

Bis(2-aminobenzthiazolyl) sulphone (BABS) was used as a new starting material for preparing polyamides. These polyamides were prepared by reacting BABS with adipoyl, sebacoyl, isophthaloyl and terephthaloyl dichlorides, and also with 4,4′-azodibenzoyl chloride or 3,3′-azodibenzoyl chloride, utilizing the solution polycondensation technique at low temperature. In addition, the model compound was synthesized by condensing the BABS with benzoyl chloride. Characterization of the monomer, model compound and the polyamides was accomplished by 1H NMR, IR and elemental analyses. The polyamides had reduced viscosities of 0.25–0.63 dI/g in DMF or DMSO at 25 °C. All the polymers dissolved readily at room temperature in polar aprotic solvents. The thermal stability of the polymers was evaluated by TGA and DSC measurements.

Liquid Crystalline Polymers: 2. Synthesis and Thermotropic Studies of Poly(Arylidene-Ether)s Containing a Cyclopentanone Moiety in the Main Chain

A novel series of poly(arylidene-ether)s containing cyclopentanone was synthesized by polycondensation of 4, 4′-diformyl-α, ω-diphenoxyalkane and 4, 4′-diformyl-2, 2′-dimethoxy-α, ω-diphenoxyalkane with cyclopentanone. The polymers were characterized by elemental and spectral analyses, inherent viscosity, solubility and thermal analyses. Their thermotropic liquid crystalline properties were examined by DSC, optical polarizing microscopy using a heated stage and thermogravimetric analyses. Almost all the polymers exhibited thermotropic liquid crystalline properties. In most cases the mesophase extends up to 358°C, where thermal decomposition prevents further observations. In addition, the crystallinity of some polymers was examined by x-ray analysis; all showed some degree of crystallinity. The morphology of one polymer was examined by scanning electron microscopy (SEM).

New Polymer Syntheses-I. Synthesis of Linear Unsaturated Polyesters

3,5-Bis(p-hydroxybenylidene)-isopropylpiperidinone (BHIP) and 3,5-divanillylidene-isopropylpiperidinone (DVIP) were used as new starting materials for preparing new unsaturated polyesters. The polyesters were prepared by reacting BHIP or DVIP with adipoyl, sebacoyl, isophthaloyl or terephthaloyl dichlorides utilizing the interfacial polycondensation technique. In addition, the model compounds were synthesized by reacting BHIP or DVIP with benzoyl chloride. The model compounds were characterized by 'H-NMR, IR, and elemental analyses. The polyester samples have been characterized by elemental and spectral analyses. All the synthesized polymers readily dissolved at room temperature in dimethylsulphoxide or concentrated sulphuric acid. The thermal properties of the polymers were evaluated and correlated to their structural units by TGA measurements. X-ray analysis of the polymers showed that all the polyesters are amorphous.

Arylidene Polymers VII. Synthesis and Characterization of New Polyesters of Diarylidenecycloalkanones Containing an Azo Group in the Main Chain

A new interesting class of linear, unsaturated polyesters based on diarylidenecycloalkanones containing an azo linkage in the polymer main chain have been synthesized by interfacial polycondensation of 4,4′-azodibenzoyl chloride or 3,3′-azodibenzoyl chloride with 2,5-bis(p-hydroxybenzylidene)cyclopentanone, 2,5-divanillylidenecyclopentanone, 2,6-bis(p-hydroxybenzylidene)cyclohexanone and 2,6-divanillylidenecyclohexanone at ambient temperature. The resulting polyesters were characterized by elemental analyses, IR spectroscopy, solubility and viscometry measurements. The thermal properties of the polymers were evaluated by TGA and DSC measurements and correlated to their structural units. X-ray analysis of the polymers showed that polyesters based on the meta azo linkage were totally amorphous whereas, polyesters with the para azo linkage had some degree of crystallinity. The UV-visible spectra of certain polymers were measured in m-cresol solution and showed a characteristic absorption band at 438-465 nm due to n-π* transition. In addition, the electrical properties of all polyesters were measured.

New polymer syntheses III. Synthesis and characterization of new unsaturated polycarbonates

A new interesting class of linear unsaturated polycarbonates based on 3,5-bis(p-hydroxybenzylidene)-isopropylpiperidinone (T), 3,5-divanillylidene isopropylpiperidinone (IT), or 3,5-bis(m-hydroxybenzylidene)-isopropylpiperidinone (III) have been synthesized. An interfacial phosgenation technique carried out at ambient temperature was used for the synthesis of the polycarbonates. The resulting polycarbonates were characterized by elemental analyses, infrared spectroscopy, 1H nuclear magnetic resonance spectral analysis, solubility and viscometry. The thermal behaviour of the synthesized polymers was evaluated by thermal gravimetric analysis and correlated with their structures. The crystallinity of all polymers was examined by x-ray diffraction analysis.

Arylidene Polymers XIII—Synthesis, Characterization and Morphology of New Unsaturated Polycarbonates via Phosgenation of Diarylidenecycloalkanones

A new interesting class of linear unsaturated polycarbonates based on 2,5-bis(p-hydroxybenzylidene) cyclopentanone I, 2,5-divanillylidenecyclopentanone II, 2,6-bis(p-hydroxybenzylidene) cyclohexanone III, 2,6-divanillylidenecyclohexanone IV and 2,7-bis(p-hydroxybenzylidene) cycloheptanone V have been prepared. An inter-facial phosgenation technique carried out at ambient temperature was used for the synthesis of the polycarbonates. The resulting polycarbonates were characterized by elemental analyses, infrared spectroscopy, 1H nuclear magnetic resonance spectral analyses, viscometry, differential scanning calorimetry and thermogravimetric analysis measurements. The majority of the polycarbonates were soluble in halogenated solvents. The crystallinity of all the polymers was examined by X-ray analysis. In addition, the electrical properties of the polycarbonates were tested. Furthermore, the morphology of selected examples of the polycarbonates was examined by scanning electron microscopy.

Arylidene Polymers XIV—a New Synthetic Route to Copoly(ester-thioester)s by Direct Polycondensation of Thio-acids with Diarylidenecyclohexanone

A novel method for the synthesis of copoly(ester-thioester)s of high molecular weight has been developed. These polymers were prepared readily by direct polycondensation of 4,4′-(terephthaloyldithio) diacetic acid I, 3,3′(isophthaloyldithio) diacetic acid II, or 1,8 (sebacoyldithio) diacetic acid III, with 2,6-bis(p-hydroxybenzylidene) cyclohexanone IV, and 2,6-divanillylidenecyclohexanone V, using a condensing agent consisting of a pyridine-thionyl chloride complex. The resulting polymers were characterized by elemental and spectral analyses, solubility, viscometry, differential scanning calorimetry and thermogravimetric analyses. The crystallinities of all the polymers were examined by X-ray diffraction. Several physical and thermal characteristics were correlated with their chemical structures.

Arylidene Polymers—X. Preparation and Properties of New Polyesters of Diarylidenecycloalkanones Containing Symmetrical Bis-Azomethine Groups in the Polymer Backbone

A new class of unsaturated polyesters of diarylidenecycloalkanones con taining the azomethine group in the polymer backbone has been prepared. Synthesis involved the interfacial polycondensation of 4,4'-[1,4-phenylene bis (methylidynenitrilo)] dibenzoyl chloride II with 2,5-bis(p-hydroxybertzylidene) cyclopentanone III, 2,5-di vanillylidenecyclopentanone IV, 2,6-bis(p-hydroxybenzylidene) cyclohexanone V or 2,6- divanillylidenecyclohexanone VI at ambient temperature. The resulting polyesters were characterized by elemental analyses, IR spectroscopy, solubility and viscometry measure ments. The thermal properties of the polymers were evaluated by thermogravimetric analysis and differential thermal analysis measurements and correlated to their structu ral units. The crystallinity of all polymers was examined by X-ray analysis. In addition, the electrical properties of all polyesters were measured.