Optimization of reaction for synthesis of polyisobutylene amine between amination agent and epoxy polyisobutylene

An optimization study on the amination reaction of epoxy polyisobutylene for synthesis of polyisobutylene amine is presented. The experimental results indicate that n-butanol and ethylenediamine are the suitable solvent and amination agents for the reaction, respectively. The reaction yield of the amination reaction is notably increased with the enhanced molar ratio of either n-butanol against epoxy polyisobutylene or ethylenediamine against epoxy polyisobutylene. Also, the yield is enhanced with increasing temperature and time during the experimental range. Strikingly, the yield reaches as high as 91. 30% under optimal conditions; with the molar ratio of ethylenediamine, n-butanol and PIBO of 10∶ 6∶ 1, the reaction temperature of 150 ℃ and the reaction time of 6 h. In addition, the yield of the reaction is slightly decreased with the enhanced water content of the system. Accordingly, the mass concentration of water should be controlled within 1. 7% during the reaction.

Study on RE-Modiffied Mordenite Catalysts for Amination Reaction

The effects of RE modified mordenite catalysts on the activity and selectivity of amination reaction at atmospheric pressure in a fixed bed reactor were studied. The experimental result shows that the Y modified mordenite catalyst exhibits very good activity and selectivity to dimethylamine(DMA). The results of the catalyst characterization demonstrate that the rare earth modification of mordenite mainly causes the changes of B acidic sites in mordenite. The crystal structure and the Si/Al ratio on the surface of mordenite basically remain unchanged after mordenite is modified by rare earth elements. Rare earth modification improves the thermal stability and prolongs the life of the catalyst.

One-step Eco-friendly Fabrication of Antibacterial Polyester Via On-line Amination Reaction by Melt Coextrusion

The work is dedicated to develop a one-step eco-friendly method to prepare antibacterial polyethylene terephthalate(PET).We report a one-step eco-friendly method to manufacture antibacterial PET via on-line amination reaction by melt coextrusion.Beside evenly mixing of poly(hexamethylene guanidine)(PHMG)and PET in the melt coextrusion procedure,the amination reaction also occurred between PHMG and PET under high temperature(230-270℃).The antibacterial ability of composite PET showed obvious PHMG concentration dependence,and antibacterial activity reached more than 99%when PHMG content was 2.5 wt%.Moreover,LIVE/DEAD fluorescence test further confirmed that the composite PET could kill bacteria quickly and efiectively(within 30 min);while negligible cytotoxicity was observed to HSF and HUVEC cells.Onestep eco-friendly fabrication of composite antibacterial PET was accomplished by on-line melt coextrusion.The composite antibacterial PET has potential use in multiple fields to combat with pathogenic including textiles,packaging materials,decoration materials and biomedical devices,etc.

Predicting Rate Constants for Nucleophilic Reactions of Amines with Diarylcarbenium Ions Using an ONIOM Method

The rate constants of the nucleophilic reactions between amines and benzhydrylium ions were calculated using first-principles theoretical methods. Solvation models including PCM, CPCM, and COSMORS, as well as different types of atomic radii including UA0, UAKS, UAHF, Bondi, and UFF, and several single-point energy calculation methods （B3LYP, B3P86, B3PW91, BHANDH, PBEPBE, BMK, M06, MP2, and ONIOM method） were examined. By comparing the correlation between experimental rate constants and the calculated values, the ONIOM（CCSD（T）/6-311＋＋G（2df,2p）：B3LYP/6-311＋＋G（2df,2p））//B3LYP/6- 31G（d）/PCM/UFF） method was found to perform the best. This method was then employed to calculate the rate constants of the reactions between diverse amines and diarylcarbenium ions. The calculated rate constants for 65 reactions of amines with diarylcarbenium ions are in agreement with the experimental values, indicating that it is feasible to predict the rate constant of a reaction between an amine and a diarylcarbenium ion through ab initio calculation.

Effects of Ni particle size on amination of monoethanolamine over Ni-Re/SiO_2 catalysts

Ni-Re/SiO2 catalysts with controllable Ni particle sizes(4.5–18.0 nm)were synthesized to investigate the effects of the particle size on the amination of monoethanolamine(MEA).The catalysts were characterized by various techniques and evaluated for the amination reaction in a trickle bed reactor at 170℃,8.0 MPa,and 0.5 h^-1 liquid hourly space velocity of MEA(LHSVMEA)in NH3/H2 atmosphere.The Ni-Re/SiO2 catalyst with the lowest Ni particle size(4.5 nm)exhibited the highest yield(66.4%)of the desired amines(ethylenediamine(EDA)and piperazine(PIP)).The results of the analysis show that the turnover frequency of MEA increased slightly(from 193 to 253 h^-1)as the Ni particle sizes of the Ni-Re/SiO2 catalysts increased from 4.5 to 18.0 nm.Moreover,the product distribution could be adjusted by varying the Ni particle size.The ratio of primary to secondary amines increased from 1.0 to 2.0 upon increasing the Ni particle size from 4.5 to 18.0 nm.Further analyses reveal that the Ni particle size influenced the electronic properties of surface Ni,which in turn affected the adsorption of MEA and the reaction pathway of MEA amination.Compared to those of small Ni particles,large particles possessed a higher proportion of high-coordinated terrace Ni sites and a higher surface electron density,which favored the amination of MEA and NH3 to form EDA.

THE REACTION OF BENZOYL SUBSTITUTED HETEROCYCLIC KETENE AMINALS WITH ARYL AZIDES.A FACILE APPROACH TO SYNTHSIZE 1,5-DIARYL-4-(2-IMIDAZOLINYL)-1,2,3-TRIAZOLES

Heterocyclic ketene aminals 1 react with aryl azides 2 to give the titled compounds 3,and in some cases also with the formation of fused heterocycles 4.

The Reactions of 3, 7-Dinitrodibenzobromolium Salt with Some Amines

The reactions of 3,7-dinitrodibenzobromolium salt with some amines were studied. A reaction mechanism based on the structure of the major product 6 and the minor product 7 was proposed. The reaction was considered to proceed via a substituted benzyene intermediate.

THE REACTION OF α－OXO－α－TRIAZOLYLKETENE DITRIOACETAL WITH AMINES，HYDRAZINE AND CUANIDINE

Triazolylenzoylketene S.S-acetial(1) reacted with aniline to S, N-acetal (2). with ethylenediamine, o-phenylenediamine and ethanolamine to the corresponding cyclic N, N-acetals(3), (5) and N, O-acetal(1). Treatment of (1), (2) with guanidine and hydrazine led in the biheteroeycles(6). (7). (8)respectively

Characterization of Reaction of Primary Amine WithDiketones in Aqueous Solution

In this study,the interaction between primary amine and diketones was investigated.Three diketones with a general structure of—(CH2C(O)CH2C(O))-X-R(X is C,O or N and R is H and/or alkyl groups)were selected to react with primary amine in aqueous solutions.The reaction was in-situ monitored by Raman technique and the reaction products were identified by FTIR,NMR and LC-MS.It is found that the reaction products strongly depend on the structures of diketones.When X is nitrogen,the expected Schiff base or its analog can be obtained.However,Schiff base or its analog is not detected if X is C or O,instead,ion pairs or hydrolysis products are formed accordingly,suggesting critical impacts of acidity of CH2 inβ-diketone on the product formation.This study also shows that in-situ Raman is a powerful technique for reaction monitoring and structure characterization,which is useful for mechanism understanding.

Statistical deduction and experimental verification on kinetic equations for the curing reactions of epoxy resins/amines

Based on three typical mechanisms (second-order, third-order and competitive mechanisms) for the curing reactions of the epoxy resins with amines, a pair of the kinetic equations (for primary and secondary aminations) was presented to explain the uniformity and relationship among the three different kinetic mechanisms of the reactions. The presented macro-equations were deduced from the kinetic micro-equations by the statistics method. And the constitutive equations were verified by experimental data at different reaction times and temperatures (95°C, 60°C and 39°C), taking diglycidyl ether of bisphenol A (DGEBA) /ethyleneamine (EA) as a model.

THE RADICAL NUCLEOPHILIC SUBSTITUTION REACTION OF HETEROCYCLIC KETENE AMINALS WITH 2,4-DINITROHALOBENZENES

The anion of heterocyclic ketene aminals reacted with 2,4-dini- tro-halobenzenes to give an arylated product through the radical nucleo- philic substitution confirmed by ESR spectroscopy,ESR-spin trapping techni- que,and depression of the reaction rate by the addition of inhibitor.

PHOTOINDUCED CHARGE TRANSFER REACTION OF BENZOPHENONE WITH AMINE IN VESICLES

Photoinduced charge transfer reaction of benzophenone(BP) with, mine was carried out in the vesicles of dicetyldimethylammonium bromide (DCDAB) over wide ranges of amine concentration (0. 01～4. 0M). Linear plots of φ^(-1) vs. [TEA]^(-1) at low concentration of amine (<0.02M) and Φ^(-1) vs. [TEA]^(-2) at high concentration were obtained. Kinetic data demonstrate that the electron transfer is promoted significantly by DCDAB vesicles and proton transfer becomes more efficient at high Rmlne concentrations, leading to a decrease of Kd/Kr and increase of Kh/Ke. The kinetic expressions of photoreaction of BP bound to DCDAB bilayer are developed.

Kinetics of Reaction of Bromo-epoxy Resin with Oleic Acid catalyzed by Dimethyl benzyl amine

The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to epoxy group and 0. 74 order with respect to dimethylbenzylamine. The reaction rate constants at various temperatures and activation energy were determined. The mechanism of this reaction was discussed. Keywords Tetrabromobisphenol-A, Bromo-epoxy resin, Oleic acid kinetics, Reaction mechanism

Synthesis and Anti-inflammatory Activity of 2-(E)-(4-Hy-droxy-3-methoxybenzylidene)-5-(N-Substituted aminomethyl)Cyclopentanones

A series of 2 (E) (4 hydroxy 3 methoxybenzylidene) 5 (N substituted ami nomethyl) cyclopentanones was synthesized and evaluated for the anti inflammatory activity. All of the target compounds were confirmed by spectral analysis and elemental analysis. Preliminary pharmacological tests showed that several compounds exerted appreciable inhibitory effect on xylene induced ear edema in mice and that alteration of the substituents of anilines had significant influence in anti inflammatory potency.

A Facile and Efficient Synthesis of N,N-Dimethylarylamines from Aryl Bromides

Catalytic amination of aryl bromides with in situ generated dimethylamines from N, N- dimethylacetamide (DMA) has been successfully carried out using Ni(Phen)Cl2 as catalyst. Both electron-rich and electron-poor aromatic system reacted smoothly under the conditions to give N,N-dimethylarylamines in good yields.

Recent advances in fixation of CO_(2) into organic carbamates through multicomponent reaction strategies

Carbon dioxide(CO_(2)) is the main greenhouse gas and also an ideal C1 feedstock in organic synthesis because it is abundant,nontoxic,nonflammable,and renewable.The synthesis of organic carbamates using CO_(2) as a phosgene alternative has attracted extensive attention because of the importance of carbamates in organic synthesis and in the pharmaceutical and agrochemical industries.In recent decades,many multicomponent reaction strategies have been designed for constructing different types of organic carbamate molecules.Most of these methods rely on the in situ generation of carbamate anions from CO_(2) and amines,followed by reactions with other coupling partners.Synthetic strategies for acyclic carbamates include nucleophile‐electrophile coupling,nucleo‐phile‐nucleophile oxidative coupling,difunctionalization of unsaturated hydrocarbons,and C–H bond functionalization.Strategies for the synthesizing cyclic carbamates include carboxylative cyclization of in situ‐generated unsaturated amines and difunctionalization of unsaturated amines with CO_(2) and other electrophilic reagents.This review summarizes the recent advances in the synthesis of organic carbamates from CO_(2) using different multicomponent reaction strategies.Future perspectives and challenges in the incorporation of CO_(2) into carbamates are also presented.

Amine axial ligand-coordinated cobalt phthalocyanine-based catalyst for flow-type membraneless hydrogen peroxide fuel cell or enzymatic biofuel cell

In this study,an amine-coordinated cobalt phthalocyanine(CoPc)-based anodic catalyst was fabricated by a facile process,to enhance the performance of hydrogen peroxide fuel cells(HPFCs) and enzymatic biofuel cells(EBCs).For this purpose,polyethyleneimine(PEI) was added onto the reduced graphene oxide and CoPc composite(RGO/CoPc) to create abundant NH2 axial ligand groups,for anchoring the Co core within the CoPc.Owing to the PEI addition,the onset potential of the hydrogen peroxide oxidation reaction was shifted by 0.13 V in the negative direction(0.02 V) and the current density was improved by 1.92 times(1.297 mA cm^(-2)),compared to those for RGO/CoPc(0.15 V and 0.676 mA cm^(-2),respectively),due to the formation of donor-acceptor dyads and the prevention of CoPc from leaching out.The biocatalyst using glucose oxidase(GOx)([RGO/CoPc]/PEI/GOx) showed a better onset potential and catalytic activity(0.15 V and 318.7 μA cm^(-2)) than comparable structures,as well as significantly improved operational durability and long-term stability.This is also attributed to PEI,which created a favorable microenvironment for the enzyme.The maximum power densities(MPDs) and open-circuit voltages(OCVs) obtained for HPFCs and EBCs using the suggested catalyst were 105.2±1.3 μW cm^(-2)(0.317±0.003 V) and 25.4±0.9 μW cm^(-2)(0.283±0.007 V),respectively.This shows that the amine axial ligand effectively improves the performance of the actual driving HPFCs and EBCs.

气相条件下Criegee中间体与痕量酸碱物种的双分子反应研究进展

气相臭氧化反应是不饱和烯烃在大气中重要的降解途径之一.反应会生成一个关键的Criegee中间体,该中间体有非常活跃的反应活性,可以发生单分子分解反应生成羟基自由基和烷氧自由基,也可以与大气中其他化合物发生双分子反应,生成复杂的反应产物.受测量手段的限制和大气丰度的影响,关于Criegee中间体双分子反应的研究主要集中在与H_(2)O、(H_(2)O)2及SO_(2)的反应.大气中的无机酸、有机酸、氨和有机胺是大气中痕量、具有高反应活性的化合物,在维持大气酸碱平衡、新粒子生成及二次有机气溶胶形成过程中发挥重要作用.近年的研究指出,Criegee中间体与这些痕量酸碱气体反应速率接近碰撞极限,并生成低挥发性有机物,颠覆了以往研究中认为的反应可以忽略的结论.结合前人的研究成果,对Criegee中间体双分子反应机理做了简要总结,着重阐述了Criegee中间体与无机酸和有机酸以及与氨和有机胺在大气中的双分子反应过程.从文献的梳理中我们发现Criegee中间体与有机酸和有机胺的双分子反应均可以无势垒发生,并且有低聚产物生成,这些机理的提出对于现有的全球化学传输模型和新粒子形成模型可能有重要影响.