Synthesis and characterization of conducting poly(aniline‐co‐o‐aminophenethyl alcohol)s

Poly(o‐aminophenethyl alcohol) and its copolymers containing the aniline unit were synthesized in aqueous hydrochloric acid medium by chemical oxidative polymerization. The chemical composition of these novel polymers was determined spectroscopically, and their viscosities were measured. These polymers exhibit good solubility in organic solvents that is attributed mainly to the polar hydroxyethyl side groups. Their structures (chain conformation and morphological structure) and properties (conductivity, electrochemical characteristics, glass transition, and degradation behavior) were characterized and then interpreted on the basis of the chemical composition along with the electronic and steric hindrance effects associated with the hydroxyethyl side group. Overall, the side group has a significant effect on the polymerization and influences the structure, chain conformation, and properties of the resultant polymer. The poly(aniline‐co‐o‐aminophenethyl alcohol)s containing 20–40 mol % o‐aminophenethyl alcohol units are potential conducting materials for microelectronic and electromagnetic shielding applications because they are easier to process than polyaniline but retain its beneficial properties. These polymers can also be used as a functional conducting polymer intermediate owing to the reactivity of the side group. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 983–994, 2002     

In-situ copolymerization of aniline with alkyl amine by APS： Kinetics and application

The kinetic study of in-situ eopolymerization of aniline with o- and p-methylaniline by ammonium persulfate （APS） has been carried out. UV-vis spectroscopic method was used to investigate the course of copolymerization. Structural characterization was studied by PT-IR spectral analysis. The electronic spectra of the copolymers poly（aniline-co-p-toluidine） and poly（aniline-co-o- toluidine） show blue shift. The shift has been observed in the bands corresponding to π→π^＊ transition as well as in the exciton transition. The increase in absorbance recorded during the reaction for different concentration of aniline, o- and p-toluidine at various intervals of time of polymerization reaction indicates a growth in the polymer formation. The resulting first-order rate constant was used to calculate the rate of copolymer formation using the rate equation -d[A]/dt = kc^n.     

Decreasing the Polymerization Potential Improves the Selectivity of PPD-Coated Disc Biosensors for Glutamate

Abstract

The selectivity of glutamate microdisc biosensors coated with poly(o-phenylenediamine) (PPD) as the interference-rejecting layer against ascorbic acid was observed to be very low. Enhancement in the selectivity was noticed when the electropolymerization potential for the polymerization of the o-phenylenediamine monomer was decreased from 0.65 V to 0.40 V vs. Ag/AgCl. The selectivity coefficient increased from ?34.93±3.75% (n = 5) to 53.05 ± 4.33% (n = 3). Decreasing the polymerization potential decreases the rate of formation of the polymer and improves the compactness of the polymer layer formed, thereby increasing the selectivity of the electrodes.     

A morphological analogue of japanese lacquer. Grafting of p-hydroxystyrene onto pullulan by ammonium persulfate initiation in dimethylsulfoxide

Pullulan-g-poly(p-acetoxystyrene) ( I ) was prepared using ammonium persulfate (APS) as an initiator in dimethylsulfoxide (DMSO) solution. I was deacetylated by hydrazine hydrate to yield pullulan-g-poly(p-hydroxystyrene) ( II ). The degree of polymerization of the grafted poly(p-hydroxystyrene) chain ( III ) was 15–20. Despite the effective grafting (%), this method caused the degradation of pullulan. The number of branch polymer chains per pullulan molecule were evaluated to be 0.9 to 2.5 from number average molecular weights of the permethylated II and III . The glass transition temperature of II was higher than that of III , indicating that the polar hydroxyl groups of pullulan in the graft polymer caused an increase in the rigidity of the grafted polymer chains. Pullulan-g-poly(o-hydroxystyrene) and pullulan-g-poly(MMA) were also readily prepared by this method.     

Amperometric glucose biosensor based on platinum nanoparticle encapsulated with a clay

Electrically conductive hollow nanospheres with an average diameter between 100 and 200 nm were prepared via a one-step polymerization of aniline in the presence of lignosulfonate (LS) by using ammonium persulfate (APS) as the oxidant. The LS concentration and molar ratio between APS and aniline, the temperature and time for polymerization were adjusted to optimize morphology, structure and electrochemical properties. Uniform hollow nanospheres are best obtained at a concentration of 18 wt% of LS, at a polymerization temperature at 25 °C, at an APS/aniline molar ratio of 1:1, and at a polymerization time of 1 to 12 h. This kind of preparation of nanospheres represents a simple and general route to polymer hollow nanospheres of controllable size, high stability, and optimizable electroconductivity.     

The preparation of conducting polyaniline–silver and poly(p-phenylenediamine)–silver nanocomposites in liquid and frozen reaction mixtures

The oxidation of aniline with silver nitrate in 1 mol L⁻¹ acetic acid at 20 °C yielded a composite of two conducting components, polyaniline and silver; the acceleration with 1 mol% of p-phenylenediamine is needed for efficient synthesis. The yield and molecular weight increased when aniline was copolymerized with 10 mol% p-phenylenediamine. Such product displayed metallic conductivity below 180 K and semiconductor type above this temperature. As the result, the conductivity was the same at 100 and 300 K. The oxidation of p-phenylenediamine alone with silver nitrate also produced a conducting composite having the conductivity of 1,750 S cm⁻¹ despite the assumed nonconductivity of poly(p-phenylenediamine). The present study demonstrates that all oxidations proceeded also in frozen reaction mixtures at −24 °C, i.e., in the solid state. In most cases, molecular weights of polymer component increased, the conductivity of composites with silver improved, to 2,990 S cm⁻¹ for poly(p-phenylenediamine)–silver, and remained high after deprotonation with 1 mol L⁻¹ ammonium hydroxide.

     

Poly(N-phenyl-2-hydroxytrimethylene amine): Its blends with poly(ϵ-caprolactone) and water-soluble polyethers

A new polymer with pendant hydroxyl groups, namely, poly(N-phenyl-2-hydroxytrime-thylene amine) (PHA), was synthesized by a direct condensation polymerization of aniline and epichlorohydrin in an alkaline medium. The new polymer is amorphous with a glass transition temperature (T_g) of 70°C. Blends of PHA with poly(ϵ-caprolactone) (PCL), as well as with two water-soluble polyethers, poly(ethylene oxide) (PEO) and poly(vinyl methyl ether) (PVME), were prepared by casting from a common solvent. It was found that all the three blends were miscible and showed a single, composition dependent glass transition temperature (T_g). FTIR studies revealed that PHA can form hydrogen bonds with PCL, PEO, and PVME, which are driving forces for the miscibility of the blends. © 1997 John Wiley & Sons, Inc.     

Guest-induced conformation shift of p-sulphonatothiacalix[4]arene in the solid state and solution manipulated by [Zn(dipy)3]2+

The ¹H NMR and X-ray analysis data reveal the guest-induced cone → partial cone and cone → 1,2-alternate conformational shift in aqueous methanol solutions and solid state for a p-sulphonatothiacalix[4]arene-[Zn(dipy)₃]²⁺ host–guest system. The experimental data, together with DFT calculations, show that the guest-induced conformational shift of p-sulphonatothiacalix[4]arene is facilitated by the deprotonation of phenolic groups.     

Polymerization of aniline derivatives by K2Cr2O7 and production of Cr2O3 nanoparticles

Oxidative polymerization of aniline, anthranilic acid, and aniline‐co‐anthranilic acid by potassium dichromate Cr(VI) as an oxidant in acidic medium was investigated. In this study, the polymerization process of aniline, o‐anthranilic acid as well as aniline/o‐anthranlic acid using K₂Cr₂O₇ produced, coordinated Cr(III)/polyaniline (PANI), Cr(III)/polyanthranilic acid (PAA) and Cr(III)/poly aniline‐co‐anthranilic acid (PANAA). The mechanism of polymerization reaction in the presence of dichromate was hypothesized. The precursor chromium doped polymers were characterized by TGA, FT‐IR, UV‐visible, XRD analyses. Cr₂O₃ nanoparticles size were determined using TEM analysis. The calcinations process of synthesized chromium doped PANI, PAA and PANAA yields Cr₂O₃ nanoparticles 26%, 31%, and 34% wt. respectively. Rhombohedral phase of Cr₂O₃ particles in the range from 33 to 61 nm was produced from chromium/polyanthranilic acid (PAA) and chromium/poly(aniline‐co‐anthranilic acid) PANAA. UV‐ visible analysis showed that optical band gaps (E_g) of doped poly aniline and its derivatives are in the range from1.55 to 1.80 using Tacu's law. The band gap values reveal that the doped chromium emeraldine base can be used as semiconductor materials. Copyright © 2016 John Wiley & Sons, Ltd.     

Porous copolymer-based cation exchanger for the off-line preconcentration of aromatic amines from water

Summary A weakly polar porous copolymer and the sulfonic acid cation exchanger based on this copolymer were tested as sorbents for off-line preconcentration of aromatic amines from water. Minicolumns packed with the 1,4-di(methacryloyloxymethyl)naphthalene—divinylbenzene copolymer and the cation exchanger were used for the solid-phase extraction of polar amines. In order to study the sorption properties of these polymeric materials, the recoveries and breakthrough volumes ofp-aminophenol,o, m andp-phenylenediamine, aniline,o andp-anisidine,p-nitroaniline, ando-toluidine were determined.     

Synthesis of poly(o‐cresol) by oxidative coupling polymerization of o‐cresol

The oxidative coupling polymerization of o‐cresol was investigated using various 2‐substituted pyridine/CuCl catalysts under an oxygen atmosphere, in which 2‐phenylpyridine/CuCl and 2‐(p‐tolyl)pyridine/CuCl catalysts yielded poly(o‐cresol)s with higher regioselectivity for 1,4‐coupling. These polymerizations produced branched and crosslinked polymers in the later stages of polymerization. These polymers showed good thermal properties, such as 5% weight loss temperatures of up to 406 °C and glass transition temperatures of up to 151 °C. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 878–884     

Thermal stability of the silica-aminopropylsilane-polyimide interface

Thermal degradation of the silica–aminopropylsilane–amic acid/imide interface was studied by modifying a high-surface-area, neutral silica gel with a number of substituted aminopropylsilanes (APS). These substrates were reacted further with phthalic anhydride or aromatic amic acid monomers and the thermal decomposition of the adsorbed/reacted materials was monitored by thermogravimetric analysis (TGA) and infrared (IR) spectroscopy. The 3-aminopropyltriethoxysilane/poly[N,N′-(p,p′-oxydiphenylene)pyromellitimide] interface was also evaluated by this method. Comparison clearly distinguishes the thermal decomposition of surface-bound APS from surface-bound alkylphthalimides, the adhesion product of alkylamines and aromatic amic acids. Alkylamine imidization with the elimination of aromatic amine (analogous to polymer scission) and the decomposition of the surface-bound imide are shown in the amic acid TGA profiles. This imidization and the accompanying aniline elimination begin at about 130°C, under nitrogen, to form the surface alkyl imide which slowly decomposes at 400°C. TGA analysis indicates that the surface-bound imide undergoes minimal degradation under nitrogen at 370 ± 10°C; temperatures above this threshold range produce changes in the APS–imide interface.     

Synthesis and properties of poly(arylene ether sulfone)s and poly(arylene ether ketones) derived from 4,4″-dihydroxy-o-terphenyl

Novel poly(arylene ether)s with a rigid and zigzag 4,4″-o-terphenyldiyl structure, introduced into the polymer backbone were synthesized by nucleophilic displacement reaction of 4,4″-dihydroxy-o-terphenyl with several activated aromatic dihalides in virtually quantitative yields. The poly(arylene ether)s having high molecular weight show both good solubility in common organic solvents and high thermal stability up to 545°C. They are amorphous with glass transition temperatures of 160–200°C.     

Effect of aromatic substitution in aniline on the properties of polyaniline

Substitution in aniline has tremendous effect in the synthesis of poly(substituted anilines) as well as in their properties. In this investigation polyaniline (PANI), poly(m-nitro aniline) (PMNA), poly(m-amino phenol) (PMAP) and poly(o-ethyl aniline) (POEA) were synthesized by oxidative polymerization under identical conditions. Different properties were measured and compared with PANI to find out the presence of electron donating -OH group, electron withdrawing -NO₂ group and less effecting ethyl group on the properties of poly(substituted anilines). It was found that presence of any type of substitution in the benzene ring of aniline increases the solubility of the resulted polymer but reduces the yield, degree of polymerization, thermal stability, electrical and thermal conductivity. The colors, bulk density, particle size, percentage of crystallinity vary considerably depending on the nature of substitution.     

六、七元瓜环与苯二胺及硝基苯胺异构体相互作用的HPLC研究

利用HPLC法考察了六、七元瓜环(Q[6], Q[7])与邻苯二胺(g1)、间苯二胺(g2)、对苯二胺(g3)、邻硝基苯胺(g4)、间硝基苯胺(g5)、对硝基苯胺(g6)的相互作用. 实验结果表明: Q[6]可与客体g1～g3, g5形成1∶1的包结配合物; Q[7]与客体g1～g6形成1∶1包结配合物, 同时计算了包结配合物的包结稳定常数, 探讨了主-客体的相互作用模式, 并利用¹H NMR、紫外吸收光谱法进行了佐证.     

Synthesis of Analogues of (1 → 6)‐Branched (1 → 3)‐Glucohexaose

Abstract

β‐D‐Galp‐(1 → 3)‐[β‐D‐Galp‐(1 → 6)‐]α‐D‐Glcp‐(1 → 3)‐β‐D‐Glcp‐(1 → 3)‐[α‐D‐Manp‐(1 → 6)‐]D‐Glcp 16 and β‐D‐Galp‐(1 → 3)‐[β‐D‐Glcp‐(1 → 6)‐]α‐D‐Glcp‐(1 → 3)‐β‐D‐Glcp‐(1 → 3)‐[α‐D‐Manp‐(1 → 6)‐]D‐Glcp 18 were synthesized as the analogues of the immunomodulator β‐D‐Glcp‐(1 → 3)‐[β‐D‐Glcp‐(1 → 6)‐]α‐D‐Glcp‐(1 → 3)‐β‐D‐Glcp‐(1 → 3)‐[β‐D‐Glcp‐(1 → 6)‐]D‐Glcp through coupling of trisaccharide donors 8 and 13 with trisaccharide acceptor 14 followed by deprotection, respectively.     

Synthesis and characterization of methanesulfonic acid doped poly(2-chloroaniline), study of its physical properties and ammonia gas sensing application

The poly(2-chloroaniline) was prepared by in situ chemical oxidative polymerization method using ammonium thiosulphate as an oxidant and methanesulfonic acid as a dopant. The optical absorption spectra showed bands for π-π* transition of the benzenoid ring at 265 nm and at 350 nm for n-π* transition of the quinonoid ring. The broad band appeared around 550 nm was due to transition of electrons from the valance band to the conduction band, this also confirmed the good electrical conductivity of the polymer. The X-ray diffraction pattern showed characteristic diffraction peak at 2θ = 26° confirming a emeraldine salt form of the poly(2-chloroaniline). The electrical conductivity of the polymer measured by the two probe method at room temperature was 2.21×10^?3 S/cm, which was found to be thermally activated. The linear increase in conductivity with increase in the temperature suggested the electron hopping mechanism. The methanesulfonic acid doped poly(2-chloroaniline) presents a linear dependency of its electrical resistance with an increase in ammonia gas concentration (1 ppm to 300 ppm) and creates a promising sensing material for ammonia gas sensing applications.     

Head-to-head vinyl polymers. X. Cyclopolymerization of o-dimethacryloyloxybenzene

To clarify the possibility of preparing a polymer that contained head-to-head (h–h) methyl methacrylate (MMA) unit radical cyclopolymerization of o-dimethacryloyloxybenzene (o-DMB) was investigated. p-Dimethacryloyloxybenzene (p-DMB) was also used in comparison. When the polymerizations were carried out with higher monomer concentrations than ca. 0.5 mol/L, benzene-insoluble polymer was produced. The extent of cyclization (f_c) in benzene-soluble polymer increased with a decrease in the monomer concentration and an increase in the polymerization temperature. The ¹H-NMR and ¹³C-NMR spectra of poly(MMA) derived from poly(o-DMB) by hydrolysis and methylation were in fairly good agreement with those of ordinary head-to-tail (h–t) poly(MMA). Therefore, it was concluded that the intramolecular propagation in cyclopolymerization of o-DMB was mainly performed by a h–t mechanism. However, the initial and maximum degradation temperatures of the poly(MMA) were observed to be somewhat higher than those of the ordinary poly(MMA), which suggests that a minor amount of the h–h unit was formed.     

Heat-gradient analytical technique for the simultaneous determination of some aromatic amines

A new sensitive analytical technique has been developed for the simultaneous determination of aromatic amines (aniline, p-nitroaniline, m-nitroaniline, o-nitroaniline, 1,3-phenylenediamine, and 1,4-phenylenediamine). It is based on the differential migration of colored derivatives formed by the reaction of diazotized amines with 8-hydroxy quinoline 5-sulphonic acid (FERRON) on a silica gel plate. Quantitative evaluation of amines is made by visual comparison of the intensities of color by spectrophotometry. The Beer’s law, molar absorptivity, and Sandell’s sensitivity have been determined. The effect of the analytical parameters on the migration and analysis have been evaluated. The method is highly reproducible and has been applied to the determination of amines in environmental samples. The text was submitted by the authors in English.