Synthesis,characterization, thermal stability and electrochemical properties of <Emphasis Type="Italic">ortho</Emphasis>-imine-functionalized oligophenol via enzymatic oxidative polycondensation

Ortho-imine functionalized oligophenol was synthesized via enzymatic polymerization of 2-((4-nitrophenylimino)methyl)phenol (NPIMP). Enzymatic polymerization was catalyzed by Horseradish peroxidase (HRP) enzyme and hydrogen peroxide (H₂O₂) oxidizer yielded oligophenol with imine functionality on the side-chain. Effects of various factors including reaction pH, temperature and solvent system on the polymerization were studied. Optimum polymerization with the highest yield (96 %) and number-average molecular weight (M _n = 7300 g/mol, degree of polymerization ≈ 30) was accomplished using equivolume mixture of acetone/pH 7.0 phosphate buffer medium at 35 °C in 24 h under air. Characterization of the resulting oligomer was accomplished by ultraviolet-visible spectroscopy (UV-Vis), fourier transform infrared spectroscopy (FT-IR), ¹H and ¹³C nuclear magnetic resonance (¹H and ¹³C NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), cyclic voltammetry (CV) and gel permeation chromatography (GPC). The polymerization involved elimination of hydrogen from NPIMP, and the oligomer possessed phenolic –OH end groups. The oligomer backbone was composed of oxyphenylene and phenylene repeat units. The optical band gaps (Eg) of NPIMP and oligo(NPIMP) were measured as 3.21 and 3.39 Eg, respectively. Thermal stability of the oligo(NPIMP) was also found to be relatively high, and lost 5 % of its mass at 175 °C and lost 50 % of its mass at 600 °C.     

Synthesis and characterization of fluoropoly(amide–sulfonamide)s via polycondensation

Novel fluorine-containing polymers, fluoropoly(amide–sulfonamide)s were synthesized for the first time by polycondensation from β-hydroxytetrafluoroethanesulfonic acid sultone (TFE-sultone) and hexamethylenediamine. The chemical structures of the obtained F-PASAs were characterized by intrinsic viscosity measurements, GPC, FTIR, ¹H NMR, ¹⁹F NMR and element analysis in detail. Thermal properties and optical property of F-PASAs were investigated by DSC, DMA, TGA and UV–vis spectra, respectively. The investigation indicated that these functional fluoropolymers in which there are both amide and sulfonamide linkages along the polymer main chains possessed distinctive structure as well as unique properties such as thermal properties, clean and high transparency and compatibility with nylons.     

Synthesis of fluorine-containing polyphosphates: low-temperature solution polycondensation of bisphenol AF and aryl phosphorodichloridates

This paper describes the synthesis of aromatic polyphosphates from the reaction of various aryl phosphorodichloridates with bisphenol AF in a chlorinated hydrocarbon solvent under low-temperature conditions. The polyphosphates obtained were characterized by IR,¹³3C- and ³¹P-NMR spectra, elemental analysis, inherent viscosity, TGA, DSC, X-ray diffraction, LOI, contact angle and molar mass measurement. All the polyphosphates obtained had high yields and the inherent viscosities were in the range 0.25–0.31 dl g⁻¹. The weight average molar masses ( ) were in the range 0.96 × 10⁴−1.33 × 10⁴ with relatively narrow molar mass distributions ( ). All the polymers, except polymer C, are stable up to 250°C, exhibited 10% loss of mass at 417–463°C, and had 20–30% residual mass at 700°C in nitrogen. The X-ray diffraction patterns revealed that all the polyphosphates are semicrystalline and polymer E, containing a flexible ether linkage, has a relatively large degree of crystallinity. The fluorine-containing polyphosphates have glass-transition temperatures between 81–108°C and polymer C, having a NO₂ group in the side chain phenyl ring, has the highest T_g value. The polyphosphates obtained from bisphenol AF showed better thermal stabilities and higher LOI values than those obtained from bisphenol A. The polyphosphates have good flame retardancy, as indicated by high limiting oxygen index values in the range of 47–60. The water contact angles (θ_w) of all polyphosphates are in the range of 76–109°. The contact angles of polymers A and B are larger than other polyphosphates which contain more oxygen content or bromine atoms (polymers C, D and E).     

双酚A改性甲阶酚醛树脂的合成和表征

利用双酚A、苯酚、甲醛水溶液为原料,在KOH的催化下,合成了一种含有羟甲基的双酚A改性甲阶酚醛树脂,研究了反应温度、反应物配比、催化剂用量、反应时间对合成的影响,并用红外光谱分析了产品的结构。结果表明,在反应温度为80℃,反应时间为3 h条件下,各反应物物质的量比的适宜范围:n(甲醛):n(苯酚)为(3.0～3.5):1,n(氢氧化钾):n(苯酚)为(0.085～0.15):1;n(双酚A):n(苯酚)为(0.1～0.35):1。     

双酚A-多聚甲醛酚醛树脂的合成与表征

采用双酚A(BPA)和多聚甲醛(PA)为原料,少量水为多聚甲醛解聚促进剂,在酸性条件下合成了高分子量热塑性酚醛树脂,并对产物的结构、元素、相对分子量、热稳定性和荧光性等进行测定.以BPA-PA酚醛树脂固含率为衡量指标,探讨了不同因素对合成的影响规律.通过响应面设计对树脂合成工艺进行优化,确定了较佳合成工艺条件为PA用量...     

Synthesis and characterization of a novel derivative of chitosan

The graft-copolymer of chitosan with 4-(6-methacryloxyhexyloxy)-4′-nitrobiphenyl I was synthesized by radical polymerization. Graft-copolymerization was carried out under homogeneous conditions with AIBN as initiator and 2 wt% acetic acid as solvent. Homopolymerization of I was also carried out to obtain material for comparative analysis. The resulting chitosan graft-copolymers were isolated, purified and characterized with FTIR, NMR, DSC, and TGA. Films were then prepared and characterized by X-ray diffraction, wave guide coupling and infrared dichroism techniques.     

Synthesis and NMR characterization of a novel polyaniline derivative

Summary The synthesis and solution-state NMR investigation of the structure of a novel type of water-soluble polyaniline (PANI) derivative in leucoemeraldine and emeraldine oxidation states is presented. Copolymers of 3-aminobenzenesulfonic acid and 2-methoxyaniline (PMAOMA) with various monomer molar ratios were synthesized by chemical polymerization in a hydrochloric acid medium. Due to a large difference in the reactivities of 2-methoxyaniline (OMA) and 3-aminobenzenesulfonic acid (MA), the content of OMA in the copolymers was much higher (over 0.65 of the mole fraction) than in the reaction mixture. Structural characterization of the reaction products was performed using one- (¹H, ¹³C) and two-dimensional (GHSQC and GCOSY) NMR spectroscopy. The NMR data indicated an almost block structure of OMA sequences of variable length separated by shorter sequences of MA units. It was also shown that the incorporation of MA units in the copolymer chains favors the formation of a less oxidized material. Received: 9 May 2000/Revised version: 4 July 2000/Accepted: 4 July 2000     

Synthesis and characterization of a new photochromic alkylene sulfide derivative

A process has been developed for the synthesis of a new photochromic alkylene sulfide derivative. The process involves the synthesis of an alkylene sulfide with terminal free amino groups and a novel unsymmetrical photochromic diarylperfluorocyclopentene containing an aldehyde group, which coupled together to produce the corresponding Schiff base. The structures of the products were confirmed by a range of spectroscopic techniques.     

含羧基的新型氨基蒽醌衍生物的合成及表征

合成、表征了一种含有羧基的新型蒽醌衍生物——1-[N-(6-羧基戊基酰基)]氨基蒽醌。     

Synthesis of poly(lactic acid)-poly(phenyl phosphate) via direct polycondensation and its characterization

Starting from d,l-lactic acid (d,l-LA), ethylene glycol (EG) and phenyl dichlorophosphate (PDP), poly(lactic acid)-poly(phenyl phosphate) was synthesized via direct copolycondensation. The novel poly(lactic acid) (PLA) copolymer containing phosphorus was characterized with FTIR, ¹H NMR, ³¹P NMR, GPC, and DSC. The GPC results showed that, after the prepolymerization of d,l-LA and EG, the direct melt copolymerization of oligomer and PDP gave copolymer with higher weight-average molecular (Mw) than the direct solution copolymerization. The optimal synthetic conditions of the direct melt copolymerization, including prepolymerization method, catalyst kinds and quantity, copolymerization temperature and time, were all discussed in detail. When catalyzed by 0.5% (weight percent) ZnO under 160°C and 70 Pa, 8 h’s copolymerization gave the copolymer with maximum Mw 9,200 Da. When the feed molar ratio of d,l-LA/EG/PDP was 20/1/1 instead of 20/1/2, the melt polymerization under the above conditions gave the copolymer with maximum Mw 27,700 Da (Mw/Mn 1.07). The novel one-step method could be an alternative route to the synthesis of poly(lactic acid)-poly(phosphate ester) instead of the traditional two-step method using lactide as intermediate. At the same time, the novel PLA copolymer containing phosphorus with phenyl group may give this material more chance for the further structure modification as expected.     

双酚A为基础的双苯并噁嗪中间体的合成与表征

双酚A为基础合成了双苯并口恶嗪中间体(BPAALF),并对其合成工艺进行了探讨。利用红外光谱(IR)、核磁共振氢谱(1H-NMR)对BPAALF的结构进行了表征。并利用差热扫描量热(DSC)对树脂的反应性进行了表征。结果表明:BPAALF合成的最佳反应温度为75℃,最佳反应时间为4h,pH值在8~10内变化对产率基本上没有影响;固化后树脂的弯曲强度为54.3MPa,冲击强度为375J·m-1。     

Synthesis,characterization and crystal structure of a zinc bis-dithiocarboxylate derivative

The zinc(II) complex, Zn(3,5-di-t-butyl-4-hydroxybenzene-dithiocarboxylate)₂(pyridine) (3) was obtained by the reaction of Zn(CH₃CN)₄(BF₄)₂ with the sodium salt of 3,5-di-t-butyl-4-hydroxybenzene-dithiocarboxylate (1) with subsequent recrystallization from pyridine. The latter salt (1) was prepared by the deprotonation of 2,6-di-t-butylphenol with NaH in THF, followed by reaction with carbon disulfide at ambient temperature. The structure of complex 3 was established by X-ray crystallography and shown to be of a distorted trigonal bipyramidal geometry with one sulfur atom from each of the dithiocarboxylate ligands occupying the axial sites. By way of contrast, Na(2,4-di-t-butylphenolate) was found to react with CS₂ to afford the xanthate derivative, Na(O-2,4-di-t-butylphenyldithiocarbonate) (4).     

Synthesis,characterization and polycondensation of Bis-(4-hydroxybutyl) terephthalate

Summary Monomeric Bis-(4-hydroxybutyl) terephthalate has been synthesized and characterized. Titanium iso-propoxide has been found to be a superior catalyst for transesterification compared to metal acetates. Further polycondensation of Bis (HBT) yields poly (1,4-butylene terephthalate). The effect of various titanium derived catalysts on the polycondensation of Bis (HBT) has been studied. The catalytic efficiency of these derivatives is ascribed to their relative hydrolytic stability and the degree of interaction between the carbonyl oxygen and the metal.     

Synthesis of a soluble polyphenol by oxidative polymerization of bisphenol-A using iron-salen complex as catalyst

Summary A soluble polyphenol was synthesized by oxidative polymerization of bisphenol-A using iron(III)-salen and hydrogen peroxide as catalyst and oxidizing agent, respectively. The addition of pyridine increased the yield and molecular weight of the polymer. NMR and IR analysis showed that the polymer was composed of a mixture of phenylene and oxyphenylene units. The iron-salen also induced the polymerization of phenol, m-cresol, and p-t-butylphenol. Received: 14 December 1998/Accepted: 13 January 1999     

Synthesis and characterization of a thiourea derivative of chitosan for platinum recovery

Chitosan is effective at removing platinum from dilute solutions, but sorption properties are significantly affected by the presence of competitor anions, such as chloride and, especially, sulfate anions. Sorption capacities in such complex solutions are enhanced by grafting thiourea through glutaraldehyde linkage. The influence of the amount of glutaraldehyde and thiourea in the impregnation bath was investigated and optimized with special attention to the composition of the solution and the type of acid used for pH control. This modification involves a change in the sorption mechanism: While glutaraldehyde‐crosslinked chitosan adsorbs platinum through an ion‐exchange mechanism, the thiourea derivative of chitosan acts as a chelating resin, less sensitive to ionic strength and competitor anions. Platinum sorption is also less sensitive to pH, and increasing the sulfate anion concentration has a limited effect on platinum sorption in comparison with the crosslinked sorbent. Thiourea grafting seems to increase sorption kinetics, especially in solutions controlled with sulfuric acid. SEM–EDAX techniques as well as FTIR analyses were used to characterize chemical modifications of the sorbent. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 119–134, 2000     

Synthesis and characterization of macrocyclic polyamine derivative of chitosan

A novel macrocyclic polyamine derivative of chitosan was synthesized by a reaction between chitosan and epoxy‐activated macrocyclic polyamine. The copolymer that is obtained contains amino functional groups in its skeleton and secondary amine and more polar hydroxyl groups. Four types of analyses were used to characterize the chemical modifications of the chitosan: elemental, FTIR spectra, solid‐state ¹³C‐NMR, and X‐ray diffraction. The adsorption properties of the macrocyclic polyamine grafted chitosan for Ag⁺, Cu²⁺, Co²⁺, and Cr³⁺ were also investigated. The experimental results showed that the new macrocyclic polyamine derivative of chitosan has high adsorption capacity and good selectivity for Ag⁺ in the presence of Ag⁺, Co²⁺, and Cr³⁺. The selectivity coefficients were K = 6.16, K = 14.81, and K = 2.42, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 924–929, 2003     

缩聚活性的铽配合物合成、表征及其性质

通过HCl气体在无水乙醇中,与Tb4O7反应生成无水TbCl3,再与具有胺基的配体反应,合成了一种两端带有胺基的呈缩聚活性的铽配合物。用元素分析、红外光谱和紫外光谱对配合物的组成和结构进行了表征,并借摩尔电导、差热-热重和荧光光谱对配合物进行了研究。配合物的起始分解温度为230℃左右,粉末状态下具有较高的荧光强度,单色性好,在DMF中可作为聚合单体应用。     

Synthesis and characterization of a novel polyurethane curing agent modified by a diazafluorene derivative

In this study, we synthesized a novel polyurethane (PU) curing agent (CA) modified by the diazafluorene derivative, 9,9′‐di(4‐hydroxyphenyl)‐9‐1H‐4,5‐diazafluorene, at different hydroxyl ratios. The results of ¹H‐NMR and Fourier transform infrared spectroscopy proved the structure of the fluorine derivative and the modification of CAs. Differential scanning calorimetry and dynamic mechanical analysis showed that the glass‐transition temperature of the PU increased with the addition of the diazafluorene derivative, and the PU cured in the novel CA had more stable and better damping properties under moderate‐temperature conditions (30–80 °C) than the PU cured in the N75 CA. Tan δ was maintained in a relatively lower range shift in the moderate‐temperature range. The average adhesion values of the PU coating cured in the novel CA increased. The scanning electron microscopy morphologies of the PU film and the average adhesion of the coatings showed that the PU cured in the novel CA had good mechanical properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46591.     

Synthesis and characterization of polyaniline derivative and silver nanoparticle composites

BACKGROUND: There has been a recent surge of interest in the synthesis and applications of electroactive polymers with incorporated metal nanoparticles. These hybrid systems are expected to display synergistic properties between the conjugated polymers and the metal nanoparticles, making them potential candidates for applications in sensors and electronic devices. RESULTS: Composites of polyaniline derivatives—polyaniline, poly(2,5‐dimethoxyaniline) and poly(aniline‐2,5‐dimethoxyaniline)—and silver nanoparticles were prepared through simultaneous polymerization of aniline derivative and reduction of AgNO₃ in the presence of poly(styrene sulfonic acid) (PSS). We used AgNO₃ as one of the initial components (1) to form the silver nanoparticles and (2) as an oxidizing agent for initiation of the polymerization reaction. UV‐visible spectra of the synthesized nanocomposites reveal the synchronized formation of silver nanoparticles and polymer matrix. The morphology of the silver nanoparticles and degree of their dispersion in the nanocomposites were characterized by transmission electron microscopy. Thermogravimetric analysis and differential scanning calorimetry results indicate an enhancement of the thermal stability of the nanocomposites compared to the pure polymers. The electrical conductivity of the nanocomposites is in the range 10^?4 to 10^?2 S cm^?1. CONCLUSION: A single‐step process for the synthesis of silver nanoparticle–polyaniline derivative nanocomposites doped with PSS has been demonstrated. The approach in which silver nanoparticles are formed simultaneously during the polymerization process results in a good dispersion of the nanoparticles in the conductive polymer matrix. Copyright © 2008 Society of Chemical Industry