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1.
Quaternary ammonium salts are photobase generators. Recently, we prepared a novel quaternary ammonium tetraphenylborate salt bearing a 6‐methoxynaphthoylmethyl group. The structure of the products was confirmed by elemental analysis and 1H‐NMR. Thermogravimetry showed its good thermostability. UV spectra and fluorescence emission spectra of the samples were studied. A mass spectrometry method for the analysis of the tertiary amine and other fragments produced by photolysis was established. Photolysis was found to produce both tertiary amine and free radicals. Therefore, the products of photolysis not only could cause thermal curing of epoxide but also could initiate the free‐radical polymerization of acrylate or methyl acrylate monomer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 399–405, 2006  相似文献   

2.
Novel sulfobetaines were synthesized from two urethanes derived from 2,4‐tolylene diisocyanate (TDI) blocked with 2‐hydroxyethyl methacrylate (HEMA) and either N,N‐dimethylaminopropylamine (DMAPA) or N,N‐dimethylaminoethanolamine (DMAEA). The first‐stage reaction of TDI with HEMA was carried out in petroleum ether heterogeneously with the precipitation of the intermediate monoadduct product in the reaction solution. The second stage is a homogeneous reaction of the monoadduct with the blocking agent, DMAPA or DMAEA, in tetrahydrofuran (THF). In both reactions, an inhibitor, hydroquinone, and a catalyst, dibutyltin diacetate (DBDAc), were used. The tertiary amine urethanes were quaternized by 1,3‐propane sultone to form the two novel sulfobetaines. The results of the elemental analysis of those products along with their 1H‐NMR and IR spectra indicated that these materials were, indeed, the compounds expected. The products dissolved in strongly polar organic solvents. The copolymerization of these two monomers with comonomers such as styrene, methyl methacrylate, acrylamide, and HEMA was investigated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3447–3459, 2001  相似文献   

3.
Higher tertiary amines were prepared by transalkylation of triethylamine with commercially available alcohols such as Tergitol 15-S-3 and tridecyl alcohol. This reaction carried out at 250–300 C and 20 kg/cm2 initial hydrogen pressure, using Cu−Cr−Mn−O catalyst, gave about 80% yield of higher alkyl tertiary amines. Tertiary amine hydrochlorides, quaternary ammonium bromides and amine oxides were prepared from these tertiary amines. Specific surface tension, wetting power, foaming power and foam stability were measured. The characteristic properties with respect to tertiary amine derivatives containing ether linkages were observed. These products have excellent wetting power, reduced surface tension, low foaming power and unstable foam.  相似文献   

4.
Three new chitosan crown ethers, N‐Schiff base‐type chitosan crown ethers (I, III), and N‐secondary amino type chitosan crown ether (II) were prepared. N‐Schiff base‐type chitosan crown ethers (I, III) were synthesized by the reaction of 4′‐formylbenzo‐21‐crown‐7 with chitosan or crosslinked chitosan. N‐Secondary amino type chitosan‐crown ether (II) was prepared through the reaction of N‐Schiff base type chitosan crown ether (I) with sodium brohydride. Their structures were characterized by elemental analysis, infrared spectra analysis, X‐ray diffraction analysis, and solid‐state 13C NMR analysis. In the infrared spectra, characteristic peaks of C?N stretch vibration appeared at 1636 cm?1 for I and 1652 cm?1 for II; characteristic peaks of N? H stretch vibration appeared at 1570 cm?1 in II. The X‐ray diffraction analysis showed that the peaks at 2θ = 10° and 28° disappeared in chitosan derivatives I and III, respectively; the peak at 2θ = 10° disappeared and the peak at 2θ = 28° decreased in chitosan‐crown ether II; and the peak at 2θ = 20° decreased in all chitosan derivatives. In the solid‐state 13C NMR, characteristic aromatic carbon appeared at 129 ppm in all chitosan derivatives, and the characteristic peaks of carbon in C?N groups appeared at 151 ppm in chitosan crown ethers I and III. The adsorption and selectivity properties of I, II, and III for Pd2+, Au3+, Pt4+, Ag+, Cu2+, and Hg2+ were studied. Experimental results showed these adsorbents not only had good adsorption capacities for noble metal ions Pd2+, Au3+, Pt4+, and Ag+, but also high selectivity for the adsorption of Pd2+ with the coexistence of Cu2+ and Hg2+. Chitosan‐crown ether II only adsorbs Hg2+ and does not adsorbs Cu2+ in an aqueous system containing Pd2+, Cu2+, and Hg2+. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1886–1891, 2002  相似文献   

5.
Lignin, which is the second most abundant polymeric aromatic organic substance in wood biomass after cellulose, and contains many oxygen‐based functional groups, has been proposed as an alternative source of chemical compounds. Guaiacol, a model compound for lignin, was reacted in supercritical water using a batch‐type reactor at temperatures of 653–673 K and various pressures under an argon atmosphere. The effects of temperature and reaction time at the same pressure were combined into a single severity parameter that was used to monitor the decomposition of guaiacol to its derived compounds. The main products in aqueous solution were catechol, phenol, and o‐cresol. The amounts present approached 40.73 wt %, 14.18 wt %, and 4.45 wt %, respectively. With an increase in the reaction time at the same conditions, the amount of guaiacol decreased and the quantity of derived compounds of guaiacol increased. Based on the experimental results, a reaction mechanism for the decomposition of guaiacol was proposed. The process investigated in this study may form the basis for an efficient method of wood biomass decomposition.  相似文献   

6.
This work presents a photocatalysis‐based method to treat and purify air because of its broad applicability to common, oxidizable, air contaminants. The effect of oxygen content, temperature, water vapor, and 2‐propanol concentration on the TiO2 surface was investigated. The rate of 2‐propanol decomposition increased with increasing the oxygen content, but was reduced at temperatures higher than 100°C. When water vapor concentration was in the range of 10–355 mmol m?3, the rate of 2‐propanol decomposition was proportional to the water content. However, an opposite result was observed at a higher concentration of water vapor. 2‐Propanol was photooxidized to acetone, and eventually to carbon dioxide and water. The kinetic model of 2‐propanol photooxidation was successfully developed by the competitive Langmuir–Hinshelwood rate form, incorporating the inhibition effect coming from the formation of acetone. Copyright © 2004 Society of Chemical Industry  相似文献   

7.
A series of novel aromatic poly(ester‐ether‐imide)s with inherent viscosity values of 0.44–0.74 dL g?1 were prepared by the diphenylchlorophosphate‐activated direct polycondensation of an imide ring‐containing diacid namely 5‐(4‐trimellitimidophenoxy)‐1‐trimellitimido naphthalene ( 1 ) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. Owing to comparison of the characterization data, an ester‐containing model compound ( 2 ) was also synthesized by the reaction of 1 with phenol. The model compound 2 and the resulted polymers were fully characterized by FT‐IR and NMR spectroscopy. The ultraviolet λmax values of the poly(ester‐ether‐imide)s were also determined. The resulting polymers exhibited an excellent organosolubility in a variety of high polar solvents such as N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethyl sulfoxide, and N‐methyl‐2‐pyrrolidone. They were soluble even in common less polar organic solvents such as pyridine, m‐cresol, and tetrahydrofuran on heating. Crystallinity of the polymers was estimated by means of wide‐angle X‐ray diffraction. The resulted polymers exhibited nearly an amorphous nature. From differential scanning calorimetry thermograms, the polymers showed glass‐transition temperatures between 221 and 245°C. Thermal behaviors of the obtained polymers were characterized by thermogravimetric analysis, and the 10% weight loss temperatures of the poly(ester‐ether‐imide)s were found to be over 410°C in nitrogen. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

8.
The chemical reactions between nitrogen dioxide vapour and diphenylamine (DPA), some of its nitro/nitroso derivatives and between their consecutive products have been studied at temperatures of about 23 °C, whereby cellulose was used as substrate material. The following stabilizer compounds were used as starting components: DPA, N‐NO‐DPA, 2‐NO2‐DPA and 4‐NO2‐DPA. Concentration profiles as function of added nitrogen dioxide have been measured by HPLC. These profiles are similar to the ones obtained by accelerated aging, and the typical consecutive stabilizer products have been formed. The profiles are interpreted in terms of possible reactions. Furthermore, the influences of time and light on the decomposition of the mono‐nitro‐N‐nitroso compounds have been investigated. The consequences of these reactions are discussed to explain differences between the storage aging at ambient temperatures and the higher temperature induced accelerated aging. The reactivity towards nitrogen dioxide for each stabilizer compound was obtained by a kinetic model for the decrease of the starting component.  相似文献   

9.
The formation of Mannich bases from secondary aliphatic amines and primary alkoxymethyl compounds of urea and melamine in basic media have been studied. The rate of formation of the Mannich base is equal to the rate of decomposition of the alkoxymethyl compound. This is explained by a reaction of the amine with the Schiff base, the intermediate formed during the alkoxymethyl decomposition. In a mixture of primary alkoxymethyl and hydroxymethyl compounds of urea and melamine, the amine reacts almost selectively with the alkoxymethyl compound. An analytical method for the determination of primary dimethylene ether groups of primary alkoxymethyl groups in mixture with hydroxymethyl groups is developed.  相似文献   

10.
The reactivity of homogeneous copper catalysts towards the selective C C bond cleavage of both phenolic and non‐phenolic arylglycerol β‐aryl ether lignin model compounds has been explored. Several copper precursors, nitrogen ligands, and solvents were evaluated in order to optimize the catalyst system. Using the optimized catalyst system, copper(I) trifluoromethanesulfonate [Cu(OTf)]/L/TEMPO (L=2,6‐lutidine, TEMPO=2,2,6,6‐tetramethyl‐piperidin‐1‐yl‐oxyl), aerobic oxidation of the non‐phenolic β‐O‐4 lignin model compound proceeded with good selectivity for Cα Cβ bond cleavage, affording 3,5‐dimethoxybenzaldehyde as the major product. Aerobic oxidation of the corresponding phenolic β‐O‐4 lignin model proceeded with different selectivity, affording 2,6‐dimethoxybenzoquinone and α,β‐unsaturated aldehyde products resulting from cleavage of the Cα Caryl bond. At low catalyst concentrations, however, a change in selectivity was observed as oxidation of the benzylic secondary alcohol predominated with both substrates.

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11.
2‐(4‐morpholinothio)benzothiazole (MOR) and 2‐(4‐morpholinodithio)benzothiazole (MDB) were heated with sulfur and ZnO in a DSC. The products formed at various temperatures were identified and analyzed by HPLC. At temperatures below 200°C, decomposition of the accelerator in the absence of other curatives was slow, degradation products being mainly 2‐bisbenzothiazole‐2,2′‐disulfide (MBTS) and 2‐mercaptobenzothiazole (MBT). A rapid exothermic decomposition above 200°C resulted in the formation of MBT (or its amine salt) and 2‐(4‐morpholino)benzothiazole (MB). MOR and MDB reacted with sulfur to form higher polysulfides. MDB was shown to react more readily with sulfur than MOR and the delayed action of MOR in rubber can therefore not be ascribed to a stable polysulfide as suggested by other authors. Neither MOR nor MDB was found to react with ZnO. A limited reaction between MBT and ZnO was observed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1235–1240, 1999  相似文献   

12.
Macroporous monoliths, composed of thermoresponsive, tertiary‐aminated, and crosslinking monomers, were prepared for continuous‐flow separation of palladium(II) ions. N ‐Isopropylacrylamide was required to form the porous structure in the monoliths, indicating that the mechanism of porous structure formation involved polymerization‐induced phase separation of the poly(N ‐isopropylacrylamide) gel. Tertiary‐aminated monoliths showed adsorption selectivity for palladium(II) ions in hydrochloric media, compared with copper(II) ions. The maximum capacities of the monoliths with tertiary amine contents of 10, 20, 30, and 70 mol % for palladium(II) ions were 0.6, 1.1, 1.3, and 2.3 mmol/g, respectively. Darcy's permeabilities of water through the macroporous monolith were 10?14 to 10?13 m2, and those were comparable to that through a commercially available membrane filter with a pore size of several micrometers. In the continuous‐flow process, the macroporous monolith with tertiary amine selectively adsorbed palladium(II) ions in the coexistence of copper(II) ions with 10 times higher concentration than the palladium(II) ions. The palladium(II) ions were eluted from the macroporous monolith, and the concentration of palladium(II) ions in the eluate was up to 45 times of that in the feed solution. The average enrichment factor and total recovery percentage of palladium(II) ions were 8.7 times and 95%, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44385.  相似文献   

13.
The water soluble phthalocyanine complex trisodium tetra-4-sulfonatophthalocyanineiron(III) (Fe(TSPc)) was found to be an effective catalyst for the cleavage of the β-ether bonds in the phenolic lignin model compounds guaiacylglycol β-guaiacyl ether (1) and guaiacylglycerol β-guaiacyl ether (11). The products of these reactions were very different from those formed in the corresponding reactions catalyzed by anthraquinone (AQ) or Co(SPP).1–4 In particular, they gave large quantities of oxidized products, even though the reactions were performed in the absence of oxygen or other added oxidant. Mechanisms have been proposed for the oxidation reactions involving 1 and 11. In both cases the first step involves one electron oxidation of the lignin model compound by the catalyst. The radical derived from 1 then undergoes further one electron oxidation and deprotonation to give 4′-hydroxy-3′-methoxy-l-(2″-methoxyphenoxy)acetophenone (8) whereas that derived from 11 undergoes Cα-Cβ bond cleavage to give vanillin (4). Reactions of the reduced form of the catalyst with 8 and the quinone methides produced from the phenolic models are important routes for guaiacol formation and regeneration of the oxidized form of the catalyst. The feasibility of these proposed reaction pathways was investigated by studying the reactions of the intermediate compounds with the catalyst.  相似文献   

14.
Studies of the thermally initiated polymerization of 4‐methylstyrene using alkylperoxide in conjunction with cobalt and tertiary amine catalysts are reported. Addition of cobalt salts leads to a facile low temperature initiation of the polymerization process. The polymerization process was investigated using differential scanning calorimetry [DSC] and vibrating probe rheological measurements. Color changes which occur when the cobalt complex and peroxide are combined were studied using UV‐visible spectroscopy. The kinetics of polymerization was investigated using two different cobalt complexes. The initiation step in the polymerization is the conversion of the cobalt (II) to cobalt (III). The presence of the tertiary amine does not affect the oxidation state of the cobalt complex. The cobalt (III) complex gives a better rate of conversion than the cobalt (II) complex. The polymerization process is discussed in terms of redox reaction between the cobalt complex and the alkyperoxide. At low temperatures, the rate of conversion obeys simple Arrhenius kinetics. At higher temperatures the effects of gelation and catalysts inhibition influence the polymerization process. The polymerization process is sensitive to the level of available oxygen during the initiation step and inhibition by aldehyde is observed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

15.
This article deals with the selection of quaternary ammonium groups for synthesis of water‐soluble, photosensitive phenolic resins, containing acrylate and different quaternary ammonium salt groups (AQSPRs), via ring‐opening reactions of epoxy phenolic resin (EPR) with acrylic acid and with different tertiary amine‐protonic acid salts. Conversion of epoxy groups, solubility, photosensitive properties, and thermal decomposition of the different AQSPRs were compared. Modification of AQSPR with methanol solution of KOH to form phenolic resin containing both quaternary ammonium hydroxide groups and acrylate groups (AQHPR) was also studied. Characterization by IR spectrum, DSC, and thermal gravimetric analysis was carried out. The results showed that in the synthesis of AQSPRs containing different quaternary ammonium salt groups, the efficiency of ring‐opening reaction of epoxy phenolic resin with tertiary amine salt in terms of conversion of epoxy groups decreases in the following order: for the tertiary amine, N,N‐dimethyl benzylamine (DMBA) > triethylamine (TEA) > trimethylamine (TMA) > N,N‐dimethyl aniline (DMA) > triethanolamine (TENA) > tri(n‐butylamine) (TBA); for the protonic acid, HCl > HBr > HCOOH > HI > NaHSO3 > Cl3CCOOH > HClO4 > HBF4. All the AQSPRs except that from HClO4 can be dissolved in water, methanol, DMF, or DMSO. The gel content formed during UV exposure decreases in the following order of acids used in forming quaternary ammonium salt groups: HCl > HCOOH > NaHSO3 > Cl3CCOOH; or decreases in the following order of tertiary amines or hydrohalic acids used in forming the quaternary ammonium groups: TMA. > TEA > DBMA; HCl > HBr > HI. During thermal decomposition of EPR with about half epoxy groups of EPR ring‐opened with tertiary amine salt at 160°C for 0.5 h, water‐insoluble product was formed. The insoluble content and the % decrease of epoxy groups or halide ions increase in the following order: TMA < TEA < DMBA; HCl < HBr < HI. The % decrease of epoxy groups for the insoluble residue is nearly equal to the % decrease of halide ions. A crosslinking reaction mechanism occurred in the thermal decomposition was thus proposed. During the modification of AQSPR with KOH, conversion of quaternary ammonium chloride groups can reach above 90%. The decomposition temperature of the quaternary ammonium groups was lowered from 204 to 120°C after modification of AQSPR with KOH. The photosensitive properties of the resin after modification became lower. It is better to react DMBA · HCl with EPR so as to obtain a product with higher conversion of epoxy groups, good water solubility, moderate photosensitivity, lower decomposition temperature, and better postcuring. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2914–2922, 2004  相似文献   

16.
Energetic azoles have shown great potential as powerful energetic molecules, which find various applications in both military and civilian fields. This work describes the synthesis, characterization and performance evaluation of two energetic triazole derivatives, viz. N‐(2,4‐dinitrophenyl)‐3‐nitro‐1H‐1,2,4‐triazole ( 1a ) and N‐(2,4‐dinitrophenyl)‐3‐azido‐1H‐1,2,4‐triazole ( 1b ). The compounds were synthesized from 3‐nitro‐1,2,4‐triazole and 3‐azido‐1,2,4‐triazole, by a simple synthetic route and structurally characterized using FT‐IR and NMR (1H, 13C) spectroscopy as well as elemental analysis. Thermal analyses on the molecules were performed using simultaneous TG‐DTA. Both compounds ( 1a , 1b ) showed good thermal stability with exothermic decomposition peaks at 348 °C and 217 °C, respectively, on DTA. The energetic and sensitivity properties of both compounds like friction sensitivities and heats of formation are reported. The heats of combustion at constant volume were determined using oxygen bomb calorimetry and the results were used to calculate the standard molar heats of formation (ΔfHm). The azido derivative ( 1b ) showed a higher positive heat of formation. The thermo‐chemical properties of the compounds as well as the thermal decomposition products were predicted using the REAL thermodynamic code.  相似文献   

17.
本文合成了含有1 ̄3个萘基取代的脲类柔性开链化合物。通过对该类化合物在溶液中的光物理行为以及受溶液酸度影响的比较研究,发现多足化合物的发生性质强烈地依赖于化合物本身存在的构象形式;同时观察到以叔胺为骨架的三足化合物存在分子内光诱导电子转移反应(PET),且这一过程强烈地依赖于介质的pH值;而叔胺基的氮原子质子化将会减弱这一PET过程。  相似文献   

18.
The syntheses of distorted tetrahedral bis(pyridine)bis(trihalophenolato)cobalt(II) complexes from an aqueus solution were achieved and their characterization by FT‐IR, X‐ray, DSC, UV‐visible and elemental analysis in solid state or in melt form is reported. Polymerizations of these complexes were accomplished either at constant temperature, employing different time intervals or constant decomposition times while varying the temperature range. The slow decomposition at constant temperature leads to long chain products, whereas long chains formed at higher temperatures were during a constant time. The resulting poly(dihalophenylene oxide)s were characterized by FT‐IR, 1H NMR, 13C NMR spectral analysis, differential scanning calorimetry and molecular weight determinations by viscometric method. © 2001 Society of Chemical Industry  相似文献   

19.
Burning rate characteristics of the low‐sensitivity explosive 5‐nitro‐1,2,4‐triazol‐3‐one (NTO) have been investigated in the pressure interval of 0.1–40 MPa. The temperature distribution in the combustion wave of NTO has been measured at pressures of 0.4–2.1 MPa. Based on burning rate and thermocouple measurements, rate constants of NTO decomposition in the molten layer at 370–425 °C have been derived from a condensed‐phase combustion model (k=8.08⋅1013⋅exp(−19420/T) s−1. NTO vapor pressure above the liquid (ln P=−9914.4/T+14.82) and solid phases (ln P=−12984.4/T+20.48) has been calculated. Decomposition rates of NTO at low temperatures have been defined more exactly and it has been shown that in the interval of 180–230 °C the decomposition of solid NTO is described by the following expression: k=2.9⋅1012⋅exp(−20680/T). Taking into account the vapor pressure data obtained, the decomposition of NTO in the gas phase at 240–250 °C has been studied. Decomposition rate constants in the gaseous phase have been found to be comparable with rate constants in the solid state. Therefore, a partial decomposition in the gas cannot substantially increase the total rate. High values of the activation energy for solid‐state decomposition of NTO are not likely to be connected with a sub‐melting effect, because decomposition occurs at temperatures well below the melting point. It has been suggested that the abnormally high activation energy in the interval of 230–270 °C is a consequence of peculiarities of the NTO transitional process rather than strong bonds in the molecule. In this area, the NTO molecule undergoes isomerization into the aci‐form, followed by C3‐N2 heterocyclic bond rupture. Both processes depend on temperature, resulting in an abnormally high value of the observed activation energy.  相似文献   

20.
The temperature histories of aminoguanidinium 5,5′‐azobis‐1H‐tetrazolate (C4H14N18, AGAT) were measured in order to construct a thermal decomposition model of the compound. The effects of chamber pressure and AGAT particle size were also examined. The results of the study suggest that the thermal decomposition of AGAT occurs in three phases: solid phase, condensed phase, and residue. It was found that the condensed phase consists of decomposition zone I where dramatic temperature rise occurs, decomposition zone II where gradual temperature rise occurs, and the cooling zone where decomposition and temperature stop rising. It was also suggested that the temperature of the decomposition surface which is the interface of the solid phase and the condensed phase was ∼500 K, and that N2 and NH3 were suggested to occur in the vicinity of the decomposition surface of decomposition zone I. In addition, it was suggested that the thickness of the decomposition zones I and II decreases and that the maximum‐temperature‐reached increases with an increase in atmospheric pressure. The rate of decomposition of AGAT was found to follow Vieille's equation and the rate of decomposition increases with an increase in pressure. The rate of decomposition increased slightly with an increase in particle size.  相似文献   

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