Synthesis, characterization and photoconductive properties of optically active methacrylic polymers bearing side-chain 9-phenylcarbazole moieties

The synthesis of two novel optically active monomers containing 9-phenylcarbazole moieties, such as (S)-(+)-2-methacryloyloxy-N-[4-(9-carbazolyl)phenyl]succinimide [(S)-(+)-MCPS] and (S)-(+)-3-methacryloyloxy-N-[4-(9-carbazolyl)phenyl]pyrrolidine [(S)-(+)-MCPP], is described. Each monomer has been radically homopolymerized to afford the corresponding optically active polymeric derivatives, which have been fully characterized. Their spectroscopic, thermal and photoconductive properties were compared to those of the new achiral homopolymer poly[N-(2-methacryloyloxyethyl)-N-[4-(9-carbazolyl)phenyl]ethylamine] {poly[MCPE]}, devised as an optically inactive macromolecular model compound, as well as to analogue polymeric derivatives containing side-chain optically active carbazolyl moieties. The chiroptical properties of the chiral polymers are quantitatively higher than in the corresponding monomers. Owing to the substantially stereoirregular structure of the main chain, this suggests that the overall optical activity is mainly due to conformational dissymmetry of the macromolecules. Spectroscopic evidence suggests the presence in all polymeric derivatives of dipole-dipole interactions between the 9-phenylcarbazolyl chromophores, occurring as a consequence of their anchorage to the polymer backbone, which favours their aggregation and justifies their high decomposition temperatures.     

Synthesis,optimization and characterization of PVA-co-poly(methacrylic acid) green adsorbents and applications in environmental remediation

Polymer Bulletin - The present paper is focused on the synthesis and optimization of a green PVA-co-poly(MAA) adsorbent by free radical polymerization using N,N′-methylene-bis-acrylamide and...     

Synthesis,characterization, and utilization of methacrylic esters of polyhydric alcohols

Dimethacrylic esters of di-, tri-, and tetraethylene glycols; trimethacrylic ester of trimethylolpropane and tetramethacrylic ester of pentaerythritol were prepared by a commercially viable process in high yields and purity. These methacrylic esters were systematically characterized by infrared, ¹H and ¹³C nuclear magnetic resonance and mass spectroscopic methods. Anaerobic adhesive compositions were made based on each monomer, and their torque strengths were compared.     

Nanoconjugates of methacrylic polymers: Synthesis,characterization, and immobilization to leather

Imparting superhydrophobicity to surfaces has direct implications for developing water-repellent materials. Most hydrophobic materials cannot be applied directly to specific surfaces like leather because of noncompatibility. Although methacrylic polymers are compatible to leather, their inherent hydrophilic characteristics make it challenging to use for introducing hydrophobicity or superhydrophobicity. In this article, we present a strategy of introducing hydrophobicity in various degrees as well as superhydrophobicity to different surfaces, particularly leather and glass surfaces by using conjugates of methacrylic polymers and various carbon nanomaterials. The covalent functionalization of methacrylate polymers with carbon nanotubes and fullerenes was performed by radical polymerization in the presence or absence of chain transfer agents (CTAs). CTA was used during polymerization to introduce carboxylic acid group, necessary for chromium-assisted binding to leather to avoid leaching. A balance between the compatibility of the polymer nanoconjugates with the leather and the amount necessary for coating stabilization was studied by a rheometer. While water contact angle measurement indicated the mild hydrophobicity in most cases, we were delighted to observe superhydrophobicity in one case presumably due to increased roughness because of the presence of specific nanomaterial to overcome inherent hydrophilicity of methacrylic polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48627.     

Synthesis, characterization, electropolymerization, and theoretical study of 2,3-di-(2-thienyl)quinoxaline

Summary A new conjugated polymer combining in its structure thiophene rings and nitrogen containing heterocycles, poly[2,3-di(2-thienyl)quinoxaline], was synthesized by electrochemical methods using different experimental conditions. The monomer was electrochemically characterized. The morphology of the respective polymer was studied by SEM. The polymer shows low bandgap, dual p- and n-doping and good environmental stability. Theoretical calculations of global and local reactivity index such as frontier orbitals energy gap and Fukui functions present a good consistency with the experimental results.     

Synthesis, electropolymerization, and photoelectrochemical characterization of 2,7-di(thiophen-2-yl)-N-methylcarbazole

A new copolymer derived from 2,7-carbazole with thiophene is reported. This copolymer was obtained through the synthesis of 2,7-dibromo-N-methyl carbazole and 2-bromothiophene using a Kumada-type reaction to bond both rings and using two different kinds of Pd catalysts, [Pd(OAc)₂] and [Pd(PPh₃)₄], with significant differences in their yields. The trimer that was obtained was subsequently electropolymerized using cyclic voltammetry, and the photoelectrochemical properties were determined. Polymerization using electrochemistry showed that the trimer contains two types of possible bonds for the formation of the macromolecule, which led to the formation of two distinctly different materials. The obtained materials exhibit promising photoelectric responses suggesting that they both can be explored in the designing of photovoltaic cells.     

Synthesis,characterization, electropolymerization,and possible utilities of a new ruthenium–thiophene complex

[RuCl₂(p‐cymene)]₂ was reacted with silver triflate and thiophene to give the sandwich complex [Ru(η⁵‐C₄H₄S)(η⁶‐p‐cymene)](PF₆)₂, which was characterized with NMR spectroscopy (¹H‐NMR, ¹³C‐NMR, and ³¹P‐NMR), Fourier transform infrared spectroscopy, elemental analysis, and cyclic voltammetry. The behavior of this new complex in dimethyl sulfoxide with regard to the amount of absorbed water was investigated by both NMR and cyclic voltammetry; the formation of other species that affected electropolymerization was demonstrated. However, under optimal working conditions (in an anhydrous medium), the complex was successfully immobilized on a platinum electrode via an electro‐oxidation pathway through the thiophene ligand. This generated a highly stable, electroactive polymer film. Its response to the doping–undoping (charge–discharge) and redox processes, added to its high stability, promises important applications for this novel material. Moreover, this opens up the possibility of testing other compounds, such as [Ru(η⁵‐thiophene)(η⁶‐arene)], that were previously synthesized and reported for their electropolymerization and use as sensors according to their redox properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43559.     

Synthesis,characterization, and coating applications of chlorinated hydroxyrubber

Chlorinated hydroxyrubber has been synthesized via the chlorination of hydroxylated liquid natural rubber. The formulation examples and coatings properties of two-component chlorinated hydroxyrubber polyurethane coatings are described. © 1994 John Wiley & Sons, Inc.     

Synthesis and characterization of methacrylic acid–ethyl acrylate copolymers

Copolymerization of methacrylic acid (MAA) and ethyl acrylate (EA) was performed in aqueous medium in the presence of an emulsifier with MAA as the major component (53.7–82.3 mol %). Emulsion stability was studied as a function of concentration and the nature of the emulsifier (ionic or nonionic). Copolymers were characterized using IR and ¹H-NMR spectroscopy. ¹³C-NMR spectra of MAA–EA copolymers have been discussed in terms of their triad monomer sequence distributions. Reactivity ratios of the MAA–EA pair were determined using a nonlinear least-square errors in variables method. Partition of the monomers in aqueous and organic phases was studied using a gas chromatographic technique. A two-loci polymerization mechanism was proposed on the basis of this partition behavior and the calculated composition of the oligomeric radicals formed in the initial stages of polymerization. © 1994 John Wiley & Sons, Inc.     

Exploring the methods of synthesis,functionalization, and characterization of graphene and graphene oxide for supercapacitor applications

Graphene and graphene oxide, are attracting more attention over the last decades in the area of supercapacitor research and researchers concentrate on extensive exploration, owing to their dominating electrical conductivity, combined with mechanical properties. This review is a panoramic approach, giving insights into various aspects related to graphene and graphene oxide such as their properties, production methods, functionalities, and their applications in supercapacitors. The study ought to be beneficial to novice as well as to the domain experts. Various properties of both materials are explored and both synthesis methods are elaborated. Extra emphasis is given to bring out the role of graphene and graphene oxide in promoting the performance of supercapacitors. Synthesis methods are tabulated based on the evaluation metrics like specific capacitance and capacitance retention. Finally, the application of graphene and graphene oxide in supercapacitors are highlighted. Before concluding, perspectives along with challenges for further development are proposed and are expected to facilitate researchers in shedding light on further studies in this explorative area.     

Synthesis,characterization, and electropolymerization of Mannich bases: Influence of substituents on protective ability of organic coatings

Aminoalkyl phenol derivatives were prepared and tested for electrooxidation in alkaline hydroalcoholic electrolytes. We estimated the relative insulating character of thin (<0.3 μm) organic coatings on several metal electrodes (Fe, Cu, and Ni), through both voltammetric and potentiostatic runs. Unsaturated allyl and but‐3‐enyl groups confer the most effective passivation phenomenon, while N‐methyl‐substituted Mannich bases do not provide the good protective properties expected. This result was explained through the relative easiness of the nitrogen oxidation of these monomers, leading to parasite reactions (methoxylation of the growing polymer chains) and additional termination reactions, thereby limiting the molecular weight of the polymer. FTIRAS results showed that products of the anodic oxidative coupling process consist (especially for the nature of monomer) of a poly(oxy‐1,4‐phenylene)‐type structure. Amino and unsaturated substituted groups remain unchanged during electropolymerization, making the resulting coatings attractive to use as reactive primer layers. The thickness of the coatings was found to reach 2–5 μm in free‐water solutions. This behavior, particular to Mannich bases, was explained by the hydrophilic character of the growing polymer chains due to the presence of amino groups. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1054–1067, 2000     

Synthesis,characterization, and applications of organic-inorganic hybrid mesoporous silica

Organic-inorganic hybrid mesoporous materials composed of homogeneously distributed ethane group in a silica framework were prepared by using 1,2 bis(trimethoxysilyl) ethane (BTME) as a precursor and alkyltrimethylammoniumchloride or -bromide surfactant as a structure directing agent with or without the presence of a swelling agent, mesitylene. Characterization of the materials was performed by XRD, TEM/SEM,^29Si-/^13C-solid state NMR, and N₂-adsorption. Testing of the hybrid material as a reversed phase HPLC column stationary phase after C18 surfacefunctionalization demonstrated a promising result, which closely approaches the performance of a commercial product. Mn-salen complex tethering on the hybrid material produced a catalyst with somewhat enhanced performance in liquid phase etherification with tert-butyl hydroperoxide as oxidant. This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University.     

Synthesis,characterization, and photovoltaic applications of dithienogermole-dithienylbenzothiadiazole and -dithienylthiazolothiazole copolymers

New dithienogermole-based conjugated polymers were synthesized by the Stille coupling reactions of distannyldithienogermole and dibromoarene, and their photovoltaic properties were studied. These polymers possess low band gaps with broad absorptions covering the 400–800 nm range, and exhibit good film forming properties. Bulk hetero-junction solar cells prepared from blends of these polymers with PC₇₀BM exhibit high power conversion efficiency up to 2.38%.     

Synthesis and characterization of copolymers of carbazolylalkyl(meth)acrylates and methacrylic acid

Summary The copolymerization of 2-(9-carbazolyl)ethylmethacrylate, 3-(9-carbazolyl)propyl-2-methacrylate and 2-(9-carbazolyl)ethylacrylate with methacrylic acid has been studied obtaining the reactivity ratios of the monomers in benzene. For the estimation of molar masses and copolymer compositions esterification of the copolymers has been performed. A thermal study of the obtained copolymers related to the carbazolylalkyl(meth)acrylate content has been carried out taking into account several theories predicting the dependence of the glass transition temperature on the copolymers composition. The copolymers in which the molar fraction of methacrylic acid did not exceed ca. 65 mol % exhibit glass transition. Glass transition temperatures increase with the increase of molar fraction of methacrylic acid. Received: 7 August 2000/Revised version: 19 September 2000/Accepted: 22 December 2000     

Fabrication and electrochemical characterization of polyaniline nanorods modified with sulfonated carbon nanotubes for supercapacitor applications

The novel composites of sulfonated multi-walled carbon nanotubes (sMWCNTs) modified polyaniline (PANI) nanorods (PANI/sMWCNTs) were synthesized successfully by in situ oxidative polymerization method in the HClO₄ solution. FTIR and Raman spectra revealed the presence of π–π interaction between the PANI and the sulfonated carbon nanotubes and the formation of charge transfer composites. It was found that the specific capacitance of the PANI/sMWCNT composites was markedly influenced by their morphological structure and the content of PANI which was coated onto the sMWCNT. The specific capacitance of the PANI/sMWCNT composite exhibited a maximum value of 515.2 F g⁻¹ at the 76.4 wt% PANI. The charge–discharge tests showed the PANI/sMWCNT composites possessed a good cycling stability (below 10% capacity loss after 1000 cycles) compared to PANI nanorods.     

Synthesis,characterization, and rheological studies of methacrylic acid–ethyl acrylate–diallyl phthalate copolymers

Copolymerization of methacrylic acid (MAA) and ethyl acrylate (EA) was performed by the emulsion polymerization technique in the presence of a mixture of ionic and nonionic emulsifiers, at 85°C, using potassium persulfate as initiator (0.16 wt % of monomer). The molar ratio of MAA : EA varied between 44 : 56 and 54 : 46 in the monomer feed. Copolymers of MAA and EA were synthesized by incorporating diallyl phthalate (DAP) with varying concentrations (0–1.7 mol % of total monomer) in the feed. A copolymer latex of MAA, EA, and DAP was also prepared by the variable feed process. The intrinsic viscosity and gel content were determined. Copolymers were characterized by IR and NMR spectroscopic techniques. The composition of copolymers was determined by ¹H‐NMR spectra and sequential distribution from ¹³C{¹H}‐NMR spectra. The pH of the copolymer emulsion varied between 3 and 10 by addition of aqueous ammonia (23% w/w) and its effect on Brookfield viscosity was studied. The effects of copolymer composition, crosslinking agent concentration in the feed, monomer feed process, polymer solid contents, and shear rate on Brookfield viscosity were studied at pH ～ 8. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1430–1441, 2003     

Synthesis,characterization, and applications of novel di-2-pyridyl imine ligands

Two novel di-2-pyridyl imines, 2,4,6-trimethyl-(di-2-pyridylmethylene)aniline (1) and 2,6-di-isopropyl-(di-2-pyridylmethylene)aniline (2), were prepared through condensation reactions between 2,2′-dipyridyl ketone and 2,4,6-trimethylaniline and 2,6-di-isopropylaniline. They reacted readily with bis(benzonitrile)dichloropalladium(II) to afford palladium imine complexes. The crystal structure of the palladium complex (3) bearing the 2,4,6-trimethyl-(di-2-pyridylmethylene)aniline ligand revealed coordination of a pyridyl group and an imine group to the metal center. The novel ligands were successfully employed in the Suzuki coupling reaction of p-bromoanisole and phenylboronic acid.     

Synthesis,characterization, and applications of polyvinylpyrrolidone/SiO2 hybrid materials

This research discusses the properties of hybrid materials formed by polyvinylpyrrolidone (PVP) and tetraethoxysilane (TEOS) of different weight ratios, by the sol–gel process, to evaluate the feasibility of its application to process‐dyed nylon fabrics. After using equipment including FTIR, ¹³C‐NMR, and SEM, it was shown that PVP and SiO₂ are connected by hydrogen bonds, further showing the existence of special functional groups and the porous structure in hybrid materials. The pore size of the hybrid materials, specific volume of pores, and the specific surface area increased with increasing weight ratio of TEOS. In addition, the TGA testing results showed that the thermoresistance of hybrid materials can be improved. The color of the treated fabrics darkened if dyed nylon fabrics were treated by hybrid materials. When using metal complex acid dye for certain fabrics, when hybrid materials were used in finishing, there was significant improvement to the fabric's hygroscopicity and its colorfastness against chlorine. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1936–1942, 2005