N-substituted Poly Research Articles

Poly[N-(2-chloroprop-2-en-1-yl)aniline]s: synthesis, polymer analogous reaction, and physicochemical properties

A series of new soluble N-substituted poly(β-haloallylanilines) were synthesized by oxidative polymerization. Based on these polymers and polyphosphoric acid, various functionalized polyindoles of a new type were obtained in high yields.

Effects of the Hydrophilic-Lipophilic Balance of Alternating Peptides on Self-Assembly and Thermo-Responsive Behaviors.

A series of N-substituted poly(Gly–alter–Val) peptides were successfully synthesized for the systematic evaluation of the micellization behavior of alternating peptides. Three-component polymerization employing an aldehyde, a primary ammonium chloride, and potassium isocyanoacetate afforded four alternating peptides in excellent yields. We investigated the dependence of the hydrophilic–lipophilic balance of alternating peptides on the micellization behavior. All the aqueous solutions of alternating peptides exhibited upper critical solution temperature (UCST) behaviors, strongly indicating that the alternating binary pattern would mainly contribute to the UCST behaviors. The cloud points of alternating peptides shifted to higher temperatures as the side chains became more hydrophilic, which is opposite to the trend of typical surfactants. Such unusual micellization behaviors appeared to be dependent on the quasi-stable structure of single polymer chains formed in water.

Oxidation-Sensitive Polymersomes Based on Amphiphilic Diblock Copolypeptoids.

Stimuli-responsive polymersomes formed by amphiphilic block copolymers have attracted substantial attention as smart and robust containers for drug delivery and nano/microreactors. Biosourced amphiphilic diblock copolypeptoids were developed that can self-assemble into oxidation-responsive unilamellar vesicles. These vesicles can burst under the action of reactive oxygen species which can be the hydrogen peroxide or the singlet oxygen produced by light-activation of a photosensitizer with spatiotemporal control. Polysarcosine (PSar, also called poly(N-methyl glycine)) was selected as the hydrophilic block because of its resistance to protein adsorption and low toxicity, similar to poly(ethylene glycol) (PEG). We designed and synthesized poly(N-3-(methylthio)propyl glycine) as the hydrophobic block. Its polyglycine backbone is the same as that of PSar, and especially, its hydrophobic N-substituents, thioether side chains, can be oxidized to hydrophilic sulfoxides. These oxidation-responsive polymersomes entirely based on N-substituted poly(amino acid)s were biocompatible as confirmed by cell viability tests and may find applications in drug delivery, biosensing, biodetection, and nano/microreactors.

Effect of the α-substituted chiral side chain on the helical conformation of N-substituted poly(p-benzamide)

The effect of the side chain chiral center position on the secondary structure of oligomers and polymers of N-substituted 4-aminobenzoic acid was studied. Monomer 1 was prepared from l-alanine methyl ester hydrochloride in seven steps. The poly(p-benzamide) having an α-substituted side chain at the nitrogen atom (α-Me-PA) was obtained from the polymerization of 1 with triethylsilane, CsF, and 18-crown-6 in THF. The circular dichroism (CD) studies in solution demonstrated that α-Me-PA adopted a right-handed helical conformation in protic polar solvents, such as water and methanol, and a random structure in chloroform, indicating that solvophobic interactions played an important role in the helical folding of α-Me-PA. The tetramer of (S)-4-(sec-butylamino)benzoic acid was synthesized as a model compound of α-Me-PA. The single crystal X-ray analysis of the tetramer revealed that the right- and left-handed helical molecules existed in a one-to-one ratio in the crystal, and that the screw pitch of the right-handed helix was shorter than the left-handed helix.

N-Substituted poly(3,6-dithienylcarbazole) derivatives: a new class of redox-active electrode materials for high-performance flexible solid-state pseudocapacitors

This study presents the design, synthesis and charge storage features of novel poly(3,6-dithienylcarbazole) derivatives as redox-active materials for high performance energy storage applications.

Facile synthesis of thermo-, pH-, CO2- and oxidation-responsive poly(amido thioether)s with tunable LCST and UCST behaviors

Multi-responsive N-substituted poly(amido thioether) copolymers synthesized by one-pot amine–thiol–acrylate polyaddition could exhibit composition-dependent and stimuli-triggered single or double thermoresponsivity.

Boronate-functionalized Polymer Gel-based Insulin Delivery System with Improved Stability in Performance: A Comparative Structure–Function Study

In an attempt to develop a totally synthetic, self-regulated insulin delivery system to treat diabetes, N-substituted poly(acrylamide) copolymer gels bearing boronate functionality have been chemic...

Cononsolvency of mono- and di-alkyl N-substituted poly(acrylamide)s and poly(vinyl caprolactam)

In this comparative study we investigate the influence of the side chain substitution pattern on the volume phase transition temperature (VPTT) of thermo-sensitive polymer microgels. We especially focus on cononsolvency of water and methanol. We compare literature data for poly(N-isopropylacrylamide) (PNIPAM) that shows cononsolvency to experimental data for secondary amide poly(N-n-propylacrylamide) (PNNPAM) as well as tertiary poly(N,N-diethylacrylamide) (PDEAAM) and poly(N-vinyl-caprolactam) (PVCL). As methods we apply size determination by dynamic light scattering (DLS) as well as differential scanning calorimetry(DSC) and theoretical calculations using COSMO-RS (conductor-like screening model for real solvents). Clear differences are found for PDEAAM and PVCL in comparison to PNIPAM and PNNPAM. We ascribe the significant differences between PNIPAM and PNNPAM on the one hand and PDEAAM and PVCL on the other hand to the amide proton, which is present in PNIPAM and PNNPAM but not in the other two polymers.

A comprehensive study on utilization of N-substituted poly(2,5-dithienylpyrrole) derivatives in electrochromic devices

In this study, we disclose the utilization of the conducting homopolymer and copolymers based on 4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)–N-(ferrocenyl methyl)-phenylamine (SNS-An-Fc) and 1-(2-ethyl-hexyl)-2,5-di-thiophen-2-yl-2,3-dihydro-1H-pyrrole (SNS-HE) in electrochromic devices (ECDs). For this purpose, four different dual type, complementary colored devices were assembled in glass/ITO/poly(SNS-R)/PEDOT/ITO/glass configuration. Electrochromic properties of all devices were investigated by spectroelectrochemistry, switching, coloration efficiency, open circuit, stability studies and colorimetry measurements. When compared with the alkyl functionalized analog, tethering of ferrocene group on to polymer chain was found out to be an effective strategy to enhance coloration efficiency. Generally, the switching speeds and stability of ECDs having copolymers as their active layer were found to better than the devices of corresponding homopolymers. On the other hand devices assembled with homopolymers exhibited superior optical memory. Our studies indicate that all the ECDs have good redox stability, esthetically pleasing colors and they could be operated between 0.0V and 1.2V.

Synthesis of new poly diimides from reaction of poly acryloyl chloride and diamides.

Five N-substituted poly diimides were prepared by two steps. First step was included the preparation of five N-substituted diamides by reaction of adipoyl chloride with different amines .The second step was involved reaction of diamides with poly acryloyl chloride to obtain five new poly diimides having different physical properties which may used in different applications.

Synthesis of new poly diimides from reaction of poly acryloyl chloride and diamides.

Five N-substituted poly diimides were prepared by two steps. First step was included the preparation of five N-substituted diamides by reaction of adipoyl chloride with different amines .The second step was involved reaction of diamides with poly acryloyl chloride to obtain five new poly diimides having different physical properties which may used in different applications.

N-Substituted Poly(3,4-propylenedioxypyrrole)s: High Gap and Low Redox Potential Switching Electroactive and Electrochromic Polymers

A series of electrochromic N-substituted poly(3,4-propylenedioxypyrrole)s (PProDOPs) are reported, which exhibit the combined properties of a high (>3 eV) electronic band gap, colored oxidatively doped forms, and easily accessible, low redox potentials. Utilizing methyl (Me), propyl (Pr), octyl (Oct), propanesulfonated (PrS), and ethoxyethoxyethanol (Gly) pendants, the absorbance of the π−π* transition of the resulting polymers is blue-shifted when compared to the nonderivatized parent. For example, in the case of poly(N-ethoxyethoxyethanol ProDOP) (N-Gly PProDOP), this transition displays a maximum at 306 nm (onset at 365 nm), providing a colorless and highly transparent neutral polymer with a luminous transmittance greater than 99% for a film thickness of about 200 nm. N-Substituted PProDOPs display very well-defined cyclic voltammograms, with E1/2 < −0.1 V vs Fc/Fc+ (+0.2 V vs SCE), negative of the oxidation of water, as desired for materials having stable doped forms and long-lived redox switching pro...

EFFECT OF IONIC AND NONIONIC SUBSTITUENTS ON THE ELECTRORHEOLOGICAL CHARACTERISTICS OF POLYANILINE DERIVATIVES

We report our experimental results on the electrorheological (ER) characteristics of ER fluids consisting of suspensions of semiconducting polyaniline and copolyaniline particles in silicone oil. Ionic sodium diphenylamine sulfonate and nonionic o-ethoxyaniline were introduced to synthesize copolyanilines, i.e. N-substituted copolyaniline and poly (aniline-co-o-ethoxyaniline), respectively. ER fluids using these particles were compared. ER fluids, which contain the ionic copolymer, showed the highest ER performance among polyaniline and its copolymer systems. This result was interpreted in terms of the conductivities of the particles and their dielectric spectra.

One-pot reactions of samarium poly(oxamide) polyanion with various electrophilic reagents

Samarium poly(oxamide) polyanion generated in situ by the reductive coupling polymerization of tolylene 2,6-diisocyante with samarium(II) iodide was found to be a new type of reactive polymer bearing anion sites along the backbone. Its reactions with various electrophilic reagents, including methyl trifluoromethanesulfonate, acetyl chloride, n-butyl isocyanate, n-octyl isocyanate, benzyl and allyl bromide, 1,2-epoxy-3-phenoxypropane, isobutyraldehyde, and 1-iodobutane produced the corresponding N-substituted poly(oxamide)s in one-pot in good yields. The extents of substitution of the resulting polymers were 6–81%, depending on the electrophiles or conditions. In some cases, the resulting N-substituted poly(oxamide)s were much more soluble than the parent polymer. Thus, by this way, not only the poor solubility of the aromatic poly(oxamide) could be improved, but the introduced pendent moieties may provide opportunity for further modification of the polymer.

N-substituted poly(p-phenylene terephthalamide) film: surface characteristics and liquid-crystal alignment with high pretilt angles

N-Substituted poly(p-phenylene terephthalamide)s (PPTA) with various substituents in their side chains have been synthesized, and the surface characteristics of their films studied. N-Substituted PPTA showed high thermal stability and solubility in organic solvents, and the thin films, prepared by a casting method, showed a smooth surface with surface free energies of 30–50 erg cm–2. After rubbing with rayon fibres, the films easily aligned nematic liquid crystals at their surfaces. Pretilt angles induced at the surface of benzyl- and 4-methylbenzylsubstituted PPTAs with a high degree of substitution, were 4.6 and 8.1°, respectively. A rigid side-chain structure and a high degree of substitution are suggested as being more important than low surface free energy for inducing a high pretilt angle.

Synthesis, characterization, and properties of poly(N-alkylanilines)

A series of soluble N-substituted poly(alkylanilines) have been chemically and electrochemically synthesized with elkyl groups ranging from methyl to n-dodecyl. The syntheses were made in 1.0 M HClO 4 using (NH 4 ) 2 S 2 O 8 as oxidant or a constant-potential technique. The electrical and physical properties of the poly(N-alkylanilines) were found to depend on the length of the substituents. These polymers also show multiple and reversible optical transitions that can be ascribed to the formation of polaron and bipolaron states

Iron–sulphur clusters in ionic polymers on electrodes

The cluster [Fe4S4(SPh)4]2– can be incorporated in electrode-bound ion-exchange polymers based on N-substituted poly(pyrroles) and such electrode assemblies show well defined redox behaviour in MeCN, MeOH, and aqueous electrolytes; electrostatic binding in the polymer matrix is shown to exert a considerable influence on its primary and secondary reduction potentials, which are shifted about 180 mV positive of their solution values, suggesting that in principle ion–ion interactions could provide a mechanism for modulating cubane redox potentials in a biological matrix.

Synthesis and characterization of N-substituted poly(ethylenepyrrole): functionalization of ethylene–carbon monoxide alternating copolymers

The reactions of ethylene–carbon monoxide alternating copolymers with a variety of primary amines results in a new type of functionalized polymer derivative, N-substituted poly(ethylenepyrrole), containing a high density of pyrrolic units with versatile nitrogen-bound substituents in the molecular backbone.

N-Substituted Poly(α-amino acids). 2. Conformational Properties of Poly(γ-ethyl N-methyl-L-glutamate) in Various Solvent Mixtures

N-Substituted Poly(α-amino acids). 2. Conformational Properties of Poly(γ-ethyl N-methyl-L-glutamate) in Various Solvent Mixtures

N-Substituted Poly(α-amino acids). 1. Synthesis and Characterization of Poly(N-methyl-γ-methyl L-glutamate) and Poly(N-methyl-γ-ethyl L-glutamate)

N-Substituted Poly(α-amino acids). 1. Synthesis and Characterization of Poly(N-methyl-γ-methyl L-glutamate) and Poly(N-methyl-γ-ethyl L-glutamate)