Copolymerization of N-vinylpyrrolidone with N,N-dimethyl-N,N-diallylammonium chloride

The possibility of synthesizing copolymers of N,N-dimethyl-N,N-diallylammonium chloride (DMDAAC) and N- vinylpyrrolidone (VP) was demonstrated and the features of radical copolymerization of these monomers in aqueous and alcohol media were investigated. The optimum conditions of conducting the reaction were determined and the kinetic features of the copolymerization reaction in the region of low degrees of conversion, for which the usual order mechanisms for radical polymerization are preserved, were investigated. The dependence of the initial rate of co polymerization on the composition of the starting mixture of comonomers is nonlinear, and the rate of copolymerization decreases significantly as the concentration of DMDAAC in the starting mixture increases. The composition of copolymers formed was studied and the copolymerization constants r₁ ^ef=r₂ ^ef=1 were calculated, i.e., the system is azeotropic, which is also detected for significant degrees of conversion.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1969–1973, September, 1990.     

Feasibility of preparing a graft copolymer of cellulose and N,N-dimethyl-N,N-diallylammonium chloride

Conclusions The graft copolymer of cellulose and N,N-dimethyl-N,N-diallylammonium chloride was obtained.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 928–929, April, 1984.     

Use of N,N-dimethyl-N,N-diallylammonium chloride-maleic acid copolymer for recovery of butadiene-styrene rubber from a latex

The flocculating effect of a cationic polyelectrolyte, N,N-dimethyl-N,N-diallylammonium chloride-maleic acid copolymer, in the recovery of rubber from SKS-30 ARK butadiene-styrene latex at various concentrations of the dispersed phase and H₂SO₄ and at various temperatures was studied.     

Specific features of rubber recovery from latex with poly-N,N-dimethyl-N,N-diallylammonium chloride in the presence of cotton fiber

The effect of cotton fiber additions on the coagulating power of a cationic polyelectrolyte, poly-N,N-dimethyl-N,N-diallylammonium chloride, in rubber recovery from SKS-30 ARK latex was studied. The influence of the coagulating agent dosage and coagulation temperature on the completeness of the rubber recovery, with the polyelectrolyte introduced in the presence of cotton fiber and without it, was examined.     

Coagulation of Butadiene-Styrene Latex with Poly-N,N-dimethyl-2-hydroxypropylenammonium Chloride

The flocculating performance of a cationic polyelectrolyte, poly-N,N-dimethyl-2-hydroxypropylenammonium chloride, in recovery of butadiene-styrene rubber in the presence of sulfuric acid at various temperatures was studied. The kinetic curves of flocculation of SKS-30 ARK latex at various amounts of the flocculant added were obtained.     

Physicochemical and thermal properties and inhibiting power of a polysulfone derived from N,N-dimethyl-N,N-diallylammonium chloride

The physicochemical and thermal properties and the inhibiting power of a copolymer of N,N-dimethyl-N,N-diallylammonium chloride with sulfur dioxide were studied.     

Prospects for using the copolymer of N,N-dimethyl-N,N-diallylammonium chloride with acrylamide in production of butadiene-styrene rubber

The flocculating performance of a cationic polyelectrolyte, copolymer of N,N-dimethyl-N,N-diallylammonium chloride with acrylamide, in the recovery of butadiene-styrene rubber from latex was studied in relation to the concentrations of the dispersed phase and acidifying agent and to the temperature.     

Specific features of rubber recovery from a latex with N,N-dimethyl-N,N-diallylammonium chloride under the action of magnetic field

The influence of the magnetic field intensity and treatment time on the efficiency of coagulation of SKS-30 ARK butadiene-styrene latex in the presence of a cationic electrolyte, N,N-dimethyl-N,N-diallylammonium chloride, was examined.     

Conditions of Formation of Stable Polyelectrolyte Complexes Based on N-Succinyl Chitosan and Poly-N,N-diallyl-N,N-dimethylammonium Chloride

Russian Journal of Applied Chemistry - The influence of preparation conditions on the size characteristics and stability of particles of aqueous dispersions of positively and negatively charged...     

Synthesis and Antibacterial Action of Poly(DMAEMA-BC)with Various Molecular Weights

Antibacterial polymers of dimethylaminoethyl methacrylate benzyl ammonium chloride(DMAEMA-BC) with various molecular weights(Mws) were prepared under controlling radical polymerization conditions. The Mws of these polymers were determined by means of static multiangle laser light scattering and viscosity method. A Mark-Houwink equation was established to be [η]=0.154M0.764 for the Mw evaluation of poly(DMAEMA-BC)s. The effects of the Mws of these poly(DMAEMA-BC)s on their antibacterial activities against E. coli and S. aureus were investigated by various methods including viable cell counting, electrical conductivity titration, intracellular constituent leakage tests and electron microscopy. Our results indicate that the antibacterial efficiency of DMAEMA-BC was significantly enhanced after the monomers were polymerized into a polymer and increased obviously with the Mws,as a result of the increase of charge density. Further investigation of the molecular basis underlying the anti-bacterial role of these polymers revealed that poly(DMAEMA-BC) promoted the release of potassium ion from the membrane of bacterial cells and the release increased significantly with the Mws of the polymers used.     

Synthesis and Flocculating Power of Calcium-Containing Polyacrylate

The flocculating power of calcium-containing polyacrylate was studied. The optimal dose of this flocculant and the velocity of clarification of a model process water were determined.     

Synthesis and Flocculating Power of Pyridinium Polyelectrolytes

Synthesis of poly(1,2-dimethyl-5-vinylpyridinium methyl sulfate) and its copolymers with hydrophilic monomers by (co)polymerization initiated with water-soluble peroxides is studied. The flocculating activity of polyelectrolytes is determined in aqueous kaolin suspensions and also in dewatering of an active sludge.     

New External Calibration Curves (ECCs) for the Estimation of Molecular Weights in Various Common NMR Solvents

New external calibration curves (ECCs) for the estimation of aggregation states of small molecules in solution by DOSY NMR spectroscopy for a range of different common NMR solvents ([D₆]DMSO, C₆D₁₂, C₆D₆, CDCl₃, and CD₂Cl₂) are introduced and applied. ECCs are of avail to estimate molecular weights (MWs) from diffusion coefficients of previously unknown aggregates. This enables a straightforward and elaborate examination of (de)aggregation phenomena in solution.     

非线型缩聚物的平均分子量

本文用唐敖庆的方法研究了Aα-B_b(B′)_bC_c、D_d型缩聚物的平均分子量。将三种特例的理论曲线和实验结果相比较,两者基本相符。     

Effect of Ink Molecular Weights and Annealing Conditions on Molecular Transfer Printing

The molecular transfer printing(MTP) technique has been invented to fabricate chemical patterns with high fidelity using homopolymer inks. In this work, we systematically studied the effects of the molecular weights of homopolymer inks and transfer conditions on the MTP process. We explored a large range of molecular weights(~3.5-56 kg·mol~(-1)) of hydroxyl-terminated polystyrene(PS-OH) and hydroxyl-terminated poly(methyl methacrylate)(PMMA-OH) in the MTP process, and found that the resulting chemical patterns on replicas from all five blends were functional and able to direct the assembly of films of the same blends. The transfer temperature and the film annealing sequences had an impact on the MTP process. MTP was sensitive to the transfer temperature and could only be performed within a certain temperature range, i.e. higher than the glass transition temperature(T_g) of copolymers and lower than the rearrangement temperature of the assembled domains. Pre-organization of the blend films was also necessary for MTP since the preferential wetting of PMMA domains at the replica surface might result in the formation of a PMMA wetting layer to prevent the presentation of underlying chemical patterns to the replica surface.     

An Automatic Molecular Dispenser of Chloride

The combined activity of the 1.1.1‐cryptand and of a dicopper(II) bistren cryptate complex including chloride makes the Cl^? ion be continuously and slowly delivered to the solution, without any external intervention. The 1.1.1‐cryptand slowly releases OH^? ions, according to a defined kinetics, and each OH^? ion displaces a Cl^? ion from the cryptate. Chloride displacement induces a sharp colour change from bright yellow to aquamarine and can be conveniently monitored spectrophotometrically, even in diluted solutions. The 1.1.1‐cryptand is the motor of a molecular dispenser (the dicopper(II) cryptate) delivering chloride ion automatically, from the inside of the solution.     

Antibacterial activity and cytocompatibility of chitosan-N-hydroxy-2,3-propyl-N methyl-N,N-diallylammonium methyl sulfate

A water-soluble quaternary ammonium salt of chitosan, chitosan-N-hydroxy-2,3-propyl-N-methyl-N,N-diallylammonium methyl sulfate (MDAACS), was synthesized by reacting chitosan with methyl diallyl ammonium salt (MDAA). The results of water contact angle and swelling ratio showed that the membrane of MDAACS was more hydrophilic than chitosan. The antibacterial activities of MDAACS against Staphylococcus aureus and Klebsiella pneumoniae were evaluated with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The results showed that the antibacterial activity of MDAACS was higher than that of chitosan. The cytocompatibility was evaluated in vitro with L929 fibroblast proliferation based on MTT colorimetric assay. The results showed that cell growth was much higher on MDAACS than on chitosan.     

聚丙烯酰胺分子量对其Hofmann反应的影响

协同效应;高分子效应;聚丙烯酰胺分子量对其Hofmann反应的影响     

Synthesis of Nickel Nanoparticles by the Reduction of Its Salts Using the Modified Polyol Method in the Presence of Sodium Polyacrylates with Various Molecular Weights

Nickel nanoparticles were synthesized by the reduction of its salts by hydrazine hydrate in a polyol medium in the presence of sodium polyacrylates with molecular weights of 1200, 5100, and 8000. The nanoparticles were characterized by X-ray diffraction, scanning and transmission electron microscopy, IR spectroscopy, and thermogravimetric analysis. The effect of the synthesis conditions, such as temperature, molecular weight of sodium polyacrylate, and polyol and precursor types, on the reduction products were studied. It was shown that the average particle sizes, their aggregation and polydispersity degrees increase as the polymer molecular weight increases.