Diacid Chlorides Research Articles

High performance heteroaromatic poly(azo-ester)s and their miscible blends: Thermomechanical and conductivity profile

An interesting type of thermally stable and processable poly(azo-ester)s (PAEs) have been synthesized through the polycondensation of a novel diol—(E)-1-(5-(3-hydroxypyridylazo)thiocarbamoyl-aminonaphthyl)-3-(3-hydroxypyridylazo)thiourea, and various diacid chlorides. The dihydroxy compound containing azo group (−N=N−) was prepared via multi-step procedure in which the coupling of bisthiourea compound with diazonium chloride (in alkali) yielded the desired monomer. The polymeric materials were characterized in terms of FTIR, 1H NMR, solubility, solution viscosity, molecular weight, electrical conductivity, glass transition and thermal degradation temperatures. PAEs possessed high inherent viscosity 1.19–1.23 dL/g and molar mass (8.3–8.5) × 104. The polymers were thermally stable in the range 531–541°C (10% gravimetric loss T10) having Tg′ = 258–266°C. PAEs were, thus, melt blended with polyaniline resulting in high performance materials that potentially combined the fine thermal properties and processability of poly(azo-ester)s with electrical characteristics of polyaniline. The miscible blends exhibited good heat stability (T10 = 525–527°C, Tg = 246–252°C) and mechanical strength (61.81–63.19 MPa) compared with several polyaniline-based blends. FESEM showed nano-level homogeneity of the microstructure liable for better electrical conductivity (3.2–4.2 S/cm).

Surface Functionalized TiO2 Nanoparticle Designed for the Preparation of Chiral Poly(amide-imide) Bionanocomposites Containing Phenylalanine Linkage

The surface of titanium dioxide (TiO2) nanoparticles was treated with a silane coupling agent of γ-aminopropyl-triethoxy silane. An optically active poly(amide-imide) (PAI) was synthesized by the indirect polycondensation reaction of the L-phenylalanine based diacid chloride and 4,4′-diaminodiphenylether in the presence of triethylamine in N-methyl-2-pyrrolidone. Then PAI and surface modified TiO2 nanoparticles were used to produce a polymer based bionanocomposites (BNCs) via ultrasonic irradiation process. The obtained BNCs were characterized by means of X-ray diffraction, electron microscopy and thermogravimetric analysis techniques. The results showed that the nanoparticles are homogeneously dispersed in PAI matrix with particle size ranging from 30 to 50 nm.

Amplification of Surface-Initiated Ring-Opening Metathesis Polymerization of 5-(Perfluoro-n-alkyl)norbornenes by Macroinitiation

This article reports the enhanced rate of the surface-initiated polymerization (SIP) of 5-(perfluoro-n-alkyl)norbornenes (NBFn) by combining two SIP techniques, namely surface-initiated atom-transfer polymerization (SI-ATRP) to grow a macroinitiator and surface-initiated ring-opening metathesis polymerization (SI-ROMP) to produce the final coating. This polymerization approach promotes the rapid growth of dense partially fluorinated coatings that are highly hydrophobic and oleophobic and yield thicknesses from 4-12 μm. Specifically, the growth rate and the limiting thickness of pNBFn with different side chain lengths (n = 4, 6, 8, and 10) at various monomer concentrations and temperatures are evaluated through two approaches: growing the polymer from an initiator-terminated monolayer (control) or from a modified poly(2-hydroxyethyl methacrylate) (PHEMA) macroinitiator. X-ray photoelectron spectroscopy (XPS) analysis shows that 38% of the hydroxyl termini in the macroinitiator react with a norbornenyl diacid chloride (NBDAC) molecule, and 7% of such anchored norbornenyl groups react with a catalyst molecule. The kinetic data have been modeled to determine the propagation velocity and the termination rate constant. The PHEMA macroinitiator provides thicker films and faster growth as compared to the monolayer, achieving a 12 μm thick coating of pNBF8 in 15 min. Increasing the monomer side chain length, n, from 4 to 10 improves the growth rate and the limiting polymer thickness. Performing the polymerization process at higher temperature increases the growth rate and the limiting thickness as evidenced by an increase in the film growth rate constant. Arrhenius plots show that the reactions involved in the macroinitiation process exhibit lower activation energies than those formed from a monolayer. Electrochemical impedance spectroscopy reveals that the films exhibit resistance against ion transport in excess of 1 × 10(10) Ω·cm(2).

Synthesis, spectral and thermal characterization of polyester derived from 1,1-bis(4-hydroxyphenyl)cyclohexane

A series of polyesters with pendant cyclohexane ring as a cardo group were synthesized by reacting 1,1-bis(4-hydroxyphenyl)cylcohexane (bisphenol-Z (BPZ)) with diacid chlorides. The molecular structures of the monomer and polymers were confirmed by spectral analyses. Thermal properties were studied using thermogravimetric analysis and differential scanning calorimetry. The thermogravimetric data revealed that the polymers are stable up to 190°C and start to degrade thereafter. The thermal stability initially increases with increase in spacer length and then decreases due to negative effects of the spacer. In the present study, Arrhenius, Broido and Horowitz–Metzger models have been used to calculate the degradation kinetic parameters.

Preparation, characterization and thermal degradation study of poly(amide imide)s based on tri-component mixture of PMDA/BTDA, diamines and acid chloride

A series of poly(amide imide)s (PAIs) having alternate (amide–amide) and (imide–imide) units (polymers 1–14 and 22–35), and random distribution of amide-imide linkages (polymers 15–21 and 36–42) were prepared by low temperature solution polymerization of benzene-1,2,4,5-tetracarboxylic dianhydride (PMDA)/benzophenone-3,3′,4,4′-tetracarboxylic dianhydride (BTDA), diamines (cyclic and aromatic) and acid chloride in dimethylforamide. All the polymers were readily soluble in polar aprotic solvents with inherent viscosities in the range of 0.134–0.878. The process of cycloimidization of poly(amide amic acid)s (PAAs) to PAIs was investigated by TGA and FT-IR techniques at four different temperatures i.e., 175, 200, 225, and 260 °C. The rate of cycloimidization was calculated by taking into account the theoretical weight loss (WT), obtained from [n × Mw (H2O)/Mw (RU)] W, where Mw (H2O) molecular weight of water, W weight of PAA taken for TGA, Mw (RU) the molecular weight of repeat unit of PAA, n number of water molecules eliminated per repeat unit of PAA upon cycloimidization. For a particular diamine, the extent of percentage cycloimidization at the end of the isothermal heating was higher for PAAs containing trimellitic anhydride chloride (TMAc) unit, irrespective of the nature of the dianhydride and diamine. Thermal and thermooxidative degradation of PAIs was investigated by TGA in nitrogen and oxygen atmosphere. The initial decomposition temperatures (IDT) of polymers are above 260 °C, and vary widely (from 260 to 501 °C) depending upon the structure of the polymer backbone. PAIs containing TMAc exhibited higher thermal stability as compared to those polymers having diacid chloride units, in both N2/O2 atmospheres.

Covalent Attachment of Diamondoid Phosphonic Acid Dichlorides to Tungsten Oxide Surfaces

Diamondoids (nanometer-sized diamond-like hydrocarbons) are a novel class of carbon nanomaterials that exhibit negative electron affinity (NEA) and strong electron-phonon scattering. Surface-bound diamondoid monolayers exhibit monochromatic photoemission, a unique property that makes them ideal electron sources for electron-beam lithography and high-resolution electron microscopy. However, these applications are limited by the stability of the chemical bonding of diamondoids on surfaces. Here we demonstrate the stable covalent attachment of diamantane phosphonic dichloride on tungsten/tungsten oxide surfaces. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FTIR) spectroscopy revealed that diamondoid-functionalized tungsten oxide films were stable up to 300-350 °C, a substantial improvement over conventional diamondoid thiolate monolayers on gold, which dissociate at 100-200 °C. Extreme ultraviolet (EUV) light stimulated photoemission from these diamondoid phosphonate monolayers exhibited a characteristic monochromatic NEA peak with 0.2 eV full width at half-maximum (fwhm) at room temperature, showing that the unique monochromatization property of diamondoids remained intact after attachment. Our results demonstrate that phosphonic dichloride functionality is a promising approach for forming stable diamondoid monolayers for elevated temperature and high-current applications such as electron emission and coatings in micro/nano electromechanical systems (MEMS/NEMS).

3-Chloro-4-(5-methoxy-1H-indol-3-yl)cyclobut-3-ene-1,2-dione

The indole ring system is a prominent partial structure of several protein kinase inhibitor families. The title compound is the first example of a 5-substituted indolyl squaryl chloride with free indole nitrogen. It has been synthesized by reaction of 5-methoxyindole with squaric acid dichloride in diethyl ether and its IR, 1H-NMR, 13C-NMR, MS, UV and HPLC data are presented. This compound may prove to be a rather useful building block for the preparation of various derivatives for biological studies.

Reactivity increase of dienophiles by change of the ester substituents into the acid chlorides: cycloaddition reaction of the diacid chloride of 3,10-hexacyclo[10.2.1.15,8.02,11.03,10.04,9]hexadeca-6,13-diene-3,10-dicarboxylic acid with quadricyclane

Conversion of the ester substituents on the cyclobutene π-bond of dimethyl tricyclo[4.2.1.02,5]nona-3,7-diene-3,4-dicarboxylate to the corresponding acid chloride increases the cycloaddition reactivity toward quadricyclane so dramatically that the reaction temperature can be dropped from 180 °C (preparation of title 3,10-diester) to room temperature (preparation of the title 3,10-diacid chloride). The cycloadduct product, an acid chloride of the title ring system, is extremely docile and can be recrystallized unchanged from hot methanol.

Synthesis of Some Polyamides from Bis(thiosemicarbazone)acenaphthenequinone

Bis(thiosemicarbazone)acenaphthenequinon (LH 6) was synthesized in one step from acenaphthoquinone and thiosemicarbazone. The diamine (LH 6) was characterized by FT-IR, 1 H NMR and melting point. diamine was used to prepare novel polyamides. The low temperature solution polycondensation of ligand with aromatic ring. Diacid chlorides and high temperature polycondensation with dicarboxylic acid afforded ligand-containing polyamides with inherent viscosities of 0.31-0.38 dL/g in N-methylpyrolidone at 25 °C. The polyamides were generally soluble in a wide range of solvents such as dimethyformamide(DMF), N-Methylpyrolidone(NMP), dimthylsulfoxide (DMSO) and H 2SO 4. Thermal analysis showed that these polyamides were practically amorphous and exhibited 10% weight loss at and above 220 °C.

Preparation of novel pyridine-based poly(ether amide)s via three different routes and investigation of their properties

A new diamine was prepared via two successive reactions: 6-chloronicotinoyl chloride was reacted with 4,4′-oxydianiline and the obtained dichloro product was reacted with 5-amino-1-naphthol. A novel series of poly(ether amide)s containing flexible ether groups, pyridine polar units, and bulky naphthyl units was prepared through polycondensation reactions of the diamine with four diacids via three different routes. Polyamides were prepared by phosphorylation reaction, indirect diacid chloride reaction, and using ionic liquid medium. The effect of reaction conditions on the physical and thermal properties of the polymers such as solution viscosity, solubility, crystallinity, thermal stability, and thermal behavior were investigated.

Mono- and bi-iron chalcogenocarboxylate complexes

A series of thiocarboxylato and selenocarboxylato monomeric CpFe(CO)2ECORCOCl and dimeric [CpFe(CO)2ECO]2R iron complexes have been synthesized and characterized. The interaction of (μ-Ex)[CpFe(CO)2]2 (E = S; x = 2–4. E = Se; x = 1) with di-acid chlorides (ClCORCOCl) in a 1:1 molar ratio gave the monomeric complexes CpFe(CO)2ECORCOCl for R = 1,3-C6H4, 2,6-C5H3N, 1,2-C6H4. However, the dimeric complexes [CpFe(CO)2ECO]2R were obtained from the same reactants in a 2:1 metal-to-ligand molar ratio in which R is 1,3-C6H4, 2,6-C5H3N or C2H4. The monomer versus dimer production mainly depends on the electronic and steric factors of the R-moiety. The new monomeric and dimeric thio- and selenocarboxylato iron complexes have been characterized by spectroscopic techniques (1H- and 13C-NMR, IR) and by elemental analysis. The structures of [CpFe(CO)2SCO]2(1,3-C6H4) and its seleno analogue [CpFe(CO)2SeCO]2(1,3-C6H4) were determined by X-ray structure determination.

Novel nanocomposites based on reactive organoclay of l-tyrosine and amine end-capped poly(amide–imide): Synthesis and characterization

In the present study, a series of nanocomposite materials were successfully prepared using a poly(amide–imide) (PAI) matrix and novel reactive organoclay as a reinforcing agent. The organoclay was synthesized from Cloisite Na+ and protonated form of l-tyrosine amino acid via ion-exchange reaction. It was confirmed by Fourier transform infrared spectroscopy, X-ray powder diffraction, field emission scanning electron microscopy, transmission electron microscopy and thermogravimetry analysis techniques. An optically active PAI was synthesized via solution polycondensation reaction of N,N′-(pyromellitoyl)-bis-phenylalanine diacid chloride and 4,4′-diaminodiphenylether. Then it was end-capped with amine end groups near the completion of the reaction to interact chemically with organoclay. Organoclay/PAI nanocomposite films containing different amounts of organoclay were prepared via solution intercalation method through blending of organoclay with the PAI solution. The nanostructures and properties of the organoclay/PAI hybrids were investigated using different techniques. Thermogravimetry analysis results indicated that the addition of organoclay into the PAI matrix increased the thermal decomposition temperatures of the resulting hybrid materials. The presence of amino acids as a biodegradable segment in both novel organoclay and optically active PAI, made the resulting nanostructure materials susceptible for biodegradation.

Synthesis, thermal, and photocrosslinking studies of thermotropic liquid crystalline poly(benzylidene‐ether)esters containing α,β‐unsaturated ketone moiety in the main chain

AbstractA series of poly(benzylidene‐ether)esters containing a photoreactive benzylidene chromophore in the main chain were synthesized from 2,6‐bis(4‐hydroxy‐3‐methoxybenzylidene)cyclohexanone (BHMBCH) with various aliphatic and aromatic diacid chlorides by an interfacial polycondensation technique. The intrinsic viscosity of the synthesized homo and copolymers determined by Ubbelohde viscometer was found to be 0.12 to 0.17 dL/g. The molecular structure of the monomer and polymers was confirmed by FT‐IR, 1H NMR, and 13C NMR spectral analyses. These polymers were studied for their thermal stability and photochemical properties. Thermal properties were evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). It was found that the polymers were stable up to 280 °C and start degrading thereafter. Increase in acid methylene spacer length decreased the thermal stability. The self‐extinguishing property of the synthesized polymers was studied by calculating the limiting oxygen index (LOI) value using a Van Krevelen's equation. The influence of the length of methylene spacer on phase transition was investigated using DSC and odd‐even effect has been observed. Hot‐stage optical polarizing microscopic (HOPM) study showed that most of the polymers exhibited birefringence and opalescence properties. The photolysis of liquid crystalline poly(benzylidene‐ether)esters revealed that α,β‐unsaturated ketone moiety in the main chain dimerises through 2π + 2π cycloaddition reaction to form a cyclobutane derivative and leads to crosslinking. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

Study on constructional design and structural analysis of poly(amide-imide)/ZnO nanocomposites containing pyromellitoyl-bis-l-isoleucine moieties

Hybrid nanocomposites (NCs) produced by the dispersion of zinc oxide (ZnO) nanoparticles (NPs) in thermoplastic poly(amide-imide)s (PAIs) are designed and synthesized using ultrasonic-assisted technology. ZnO NPs were functionalized with 3-aminopropyltriethoxysilane (KH550) coupling agent to increase the hydrophobic nature of NPs. Reaction of diamine containing N-(4-hydroxyphenyl) benzamide and a diacid chloride comprising pyromellitoyl-bis-l-isoleucine segments at low temperature provided the polymeric matrix with well-designed groups. Surface treatments of ZnO NPs gave a better dispersion and enhancing possible interactions of NPs with functional units of polymer matrix. The surface-modified ZnO NPs were dispersed uniformly in the PAIs matrix using ultrasonic irradiation. The obtained NCs were characterized by Fourier-transform infrared spectroscopy, x-ray powder diffraction, atomic force microscopy, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and thermogravimetry analysis. The FE-SEM and TEM pictures confirmed the globular-like structures for NCs.

The effects of reactive organoclay on the thermal, mechanical, and microstructural properties of polymer/layered silicate nanocomposites based on chiral poly(amide-imide)s

Considering the importance of the nanocomposites, the present work focuses on some new hybrid materials prepared by introducing reactive organoclay (OC) into the chiral poly(amide-imide) (PAI) matrix. At first, Cloisite Na+ was modified with protonated l-isoleucine amino acid. Then, PAI containing phenylalanine was synthesized via solution polycondensation of chiral diacid chloride with 4,4′-diaminodiphenylsulfone and was characterized with Fourier transform infrared (FTIR) and 1H NMR techniques. At last, PAI/OC nanocomposite films containing 2, 5, 10, and 15 % of OC were prepared via solution intercalation method. The effect of OC dispersion and the interaction between OC and polymer chains on the properties of nanocomposites were investigated using FTIR, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, tensile testing of thin films, and thermogravimetry analysis techniques. The thermal stability of hybrids such as the decomposition temperature and mass residue at 800 °C was improved. Mechanical data indicated improvement in the tensile strength of the nanocomposites with OC loading up to 10 wt%. The transparency of the hybrid films was investigated by means of UV–Vis spectra.

Synthesis, structural aspects, antimicrobial activity and ion transport investigation of five new [1+1] condensed cycloheterophane peptides

Five novel [1+1] condensed cycloheterophane peptides were synthesized via reaction of pyridine-2,6-bis(2-aminothiophenoxymethyl) with several diacid chlorides: glutaryl dichloride, adipoyl dichloride, 2,2′-thiodiacetyl chloride, dithiodiglycoloyl chloride and 3,3′-thiodipropionoyl chloride combinations (L 1 –L 5 ). The compounds were characterized by elemental analyses, mass, FT-IR, 1H, and 13C NMR spectral data. The antimicrobial activities of the compounds were evaluated using the disk diffusion method in dimethyl sulfoxide as well as the minimal inhibitory concentration dilution method, against several bacteria and yeast cultures. The results were compared with those of commercial antibiotic and antifungal agents. Structure activity relationships were also discussed. Permeability of compound L 5 against Na+ and K+ were also investigated. Five novel cycoloheterophane amides were synthesized. Mass spectra reveal their [1+1] cyclic condensation. The compounds exert moderate microbial activity. Thia and aza groups seem to be a key element of microbial potency.

Amidoxime porous polymers for CO2 capture

CO2 capture from fossil fuel based electricity generation remains costly since new power plants with monoethanol amine (MEA) as the scrubbing agent are under construction. Amidoximes are known to mimic MEA, and porous polymers with amidoximes could offer a sustainable solution to carbon capture. Here we report the first amidoxime porous polymers (APPs) where aromatic polyamides (aramids) having amidoxime pendant groups were synthesized through low temperature condensation of 4,4′-oxydianiline (ODA) and p-phenylene diamine (p-PDA) with a new type of nitrile-bearing aromatic diacid chloride. The nitrile pendant groups of the polyamides were converted to an amidoxime functionality by a rapid hydroxylamine addition (APP-1 and APP-2). The CO2 adsorption capacities of these polyamides were measured at low pressure (1 bar) and two different temperatures (273 and 298 K) and high pressure (up to 225 bar – the highest measuring pressure to date) at 318 K. The low pressure CO2 uptake of APP-1 was found to be 0.32 mmol g−1 compared with APP-2 (0.07 mmol g−1) at 273 K, whereas at high pressure they showed a substantial increase in CO2 adsorption capacity exhibiting 24.69 and 11.67 mmol g−1 for APP-1 and APP-2 respectively. Both aramids were found to be solution processable, enabling membrane applications.

New Polymer Syntheses Part 56: Novel Friedel-Crafts Polyketones Containing Naphthalene Moiety: Synthesis, Characterization and Antimicrobial Activity

Novel Friedel-Crafts polyketones containing naphthalene moiety were synthesized via the electrophilic Friedel-Crafts polycondensation method. The desired polyketones were obtained by the interaction of newly synthesized dinaphthylidenecycloalkanone monomers with different aliphatic and aromatic diacid chlorides. The structures of new monomers and polymers were confirmed by elemental and spectral analyses, besides X-ray single crystal data for the two new monomers. The new polyketones were characterized by solubility, viscometry, thermal properties, scanning electron microscopy and antimicrobial activity test. All the polyketones were soluble in formic acid as protonic solvent giving yellowish to brown colors. Some of the polyketones were partially soluble in n-hexane, benzene and chloroform. The thermal properties of those polymers were evaluated by TGA; DTG and DTA measurements. The desired polyketones have high thermal stability at T10 except polymer 3b which have low T10 value. FDT for all polyketones is nearly completed at around 522–677°C. The morphological properties of polyketone 2b were tested by SEM measurements. The synthesized monomers and polymers were screened for their antibacterial and antifungal activities. They showed a moderated antibacterial activity against tested Gram-negative and Gram-positive bacteria and no significant influence against the selected fungi species except monomer 1b and polymers 2a , 3b .

Novel chiral and organosoluble nanostructure poly(ester–imide)s containing N,N′-(3,3′,4,4′-benzophenonetetracarboxylic)-3,3′,4,4′-diimido-bis-(L-tyrosine methyl ester) as a new amino acid based diol: production, morphology, and thermal properties

A new class of chiral and potentially biodegradable poly(ester–imide)s containing natural amino acids in the main chain was synthesized. In this investigation, N,N′-(3,3′,4,4′-benzophenonetetracarboxylic)-3,3′,4,4′-diimido-bis-(L-tyrosine methyl ester) as a novel diol and synthesized pyromellitic dianhydride-derived diacid chlorides containing different natural amino acids were used for polyesterification. The resulting new polymers were obtained in good yields with inherent viscosities ranging between 0.30 and 0.35 dL/g and are soluble in polar aprotic solvents. Morphology probes showed these tyrosine-containing pseudo-poly(amino acid)s were noncrystalline and nanostructure polymers. On the basis of thermogravimetric analysis data, such polymers are heat stable and can be classified as self-extinguishing polymers.

High performance new heteroaromatic poly(thiourea-imide-ester)s

A new dihydroxy monomer, 1-(2-hydroxypyridin-3-yl)-3-(2-(2-hydroxypyridin-3-yl)-1,3-dioxo-isoindoline-5-carbonyl)thiourea, with preformed trimellitic anhydride chloride-derived imide ring, pyridine and C=S moieties was synthesized. This compound was exploited to prepare three heteroaromatic poly(thiourea-imide-ester)s (PTIEs) by polycondensation with various diacid chlorides. Structural analysis of polymers was carried out by Fourier transformation infrared and nuclear magnetic resonance spectroscopy. PTIEs were readily soluble in polar solvents such as N, N-dimethylacetamide, dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone. Inherent viscosity and gel permeation chromatography measurements revealed high molar mass (140 × 102 to 101 × 102). One of the polymers showed crystalline behavior according to x-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry were adopted for the thermal analysis of the polymers. Novel aromatic PTIEs possess high weight loss temperature ( T10) in the range 524–536°C and glass transition temperature of about 223–230°C.