Copolymerization of Acrylamide with Sodium 2-Acrylamido-2-methylpropanesulfonate in Aqueous Salt Solutions

The kinetics of radical copolymerization of acrylamide with sodium 2-acrylamido-2-methylpropanesulfonate in water and in 1 M NaCl solutions at pH 9 and 30-50°C was studied. The kinetic data were interpreted with account of the state of the ionic groups and conformations of growing polymeric chains in the reaction mixtures.     

Kinetics of Radical Copolymerization of Acrylamide with Magnesium 2-Acrylamido-2-Methylpropanesulfonate in Aqueous Solutions

Kinetic features of homogeneous radical copolymerization of acrylamide with magnesium 2-acrylamido-2-methylpropanesulfonate in concentrated aqueous solutions in the presence of the initiating system potassium peroxosulfate-sodium hydrosulfite at pH 9 and 50°C were studied by dilatometric technique.     

The Kinetic Study of Copolymerization of Acrylonitrile with Allyl Alcohol in Concentrated Zinc Chloride Aqueous Solution with the Aid of a Computer

This paper presents a kinetic study of the copolymerization of acrylonitrile (AN, M₂) with allyl alcohol (AOH, M₂) in zinc chloride aqueous solution. The monomer reactivity ratios, r₁ and r₂, determined by application of the Lewis-Mayo equation to the system, are 1.60 and 0.01, respectively. The observed value of copolymer composition agrees well with one calculated by use of computer up to higher conversion. This means that the Lewis-Mayo equation may be applicable to the present system. The possibility of homopolymerization of AOH, confirmed empirically, is also sustained by numerical calculation.     

Polymerization of Acrylamide and Copolymerization with Acrylonitrile with AIEt3-Hexamethyl Phosphoric Acid Triamide Complex

The polymerization of acrylamide and its copolymerization with acrylonitrile were investigated with AIEt₃ and AIET₃-hexamethyl phosphoric acid triamide. AIEt₃ initiates the polymerization of acrylamide. The addition of hexamethyl phosphoric acid triamide greatly influences the yields of methanol-insoluble polymer, η_sp/c, and the structure of polymer. Vinyl polymerization is dominant with AIET₃ in the presence of hexamethyl phosphoric acid triamide. On copolymerization of acrylamide with acrylonitrile, the acrylonitrile content in the copolymer increased with the addition of hexamethyl phosphoric acid triamide on AIEt₃.     

Synthesis of New Sulfonic Acid Acrylamide Derivative from Acrylonitrile,Camphene, and Oleum

Synthesis of a new monomer, 2-acrylamido-7,7-dimethyl-1-sulfomethylbicyclo[2.2.1]heptane, is described.     

Effect of Alkali Metal Cation on Copolymerization of Acrylamide with Salts of 2-Acrylamido-2-methylpropanesulfonic Acid in Aqueous Solutions

The kinetics of radical copolymerization of acrylamide with lithium, sodium, and potassium 2-acrylamido-2-methylpropanesulfonates in concentrated aqueous solutions in the presence of potassium persulfate as initiating agent at pH 9 and 50°C was studied by dilatometry.     

Copolymerization of Acrylonitrile with Functional Silanes

Acrylonitrile (AN) has been copolymerized with vinyltriethoxy-silane (VTES) and vinyltris(methoxy ethoxy)silane (VTMES) in bulk at 60°C using benzoyl peroxide. The copolymer composition has been determined from elemental analysis. The reactivity ratios of AN (MI) copolymerizations with VTES (r₁ = 4.72, r₂ = 0) and VTMES (r₁ = 2.45, r₂ = 0) have been determined. Mechanistic explanations of the monomer reactivities are presented. The structure-property relationship of AN-vinylsilane copolymers has been discussed.     

丙烯腈在聚丙烯上接枝共聚

丙烯腈在聚丙烯上非均相接枝共聚，得杨梅形氰基树脂。研究了接枝共聚条件对单体转化率和接枝率的影响。表观聚合速度可表示为，碰撞频率因子和聚合活化能分别是1．36×1011s-1和99．2kJ．mol-1。从光学显微镜观察到改性树脂在水中接枝连束的分布状态。丙烯腈和二乙烯基苯在聚丙烯上接校共聚，再经二甲苯率取，得笼形氰基树脂。二乙烯基苯在单体中的相对含量对树脂的溶胀性能和笼孔尺寸有很大的影响，制取功能材料时应予适当调节。扫描电镜照片展示了笼形树脂的笼腔和网络结构形态。     

Copolymerization of Acrylamide with Salts of 2-Acrylamido-2-methylpropanesulfic Acid in Aqueous Solutions as Influenced by the Nature of Double-Charged Cation

The kinetics of copolymerization of acrylamide with magnesium, calcium, and strontium 2-acryl-amido-2-methylpropanesulfonates in aqueous solutions in the presence of potassium persulfate-sodium hydrosulfite initiating redox system at pH 9 and 50°C was studied as influenced by the cation nature.     

Hydrolysis of 2-Hydroxyethyl Methacrylate in Concentrated Aqueous Solutions

Hydrolysis of 2-hydroxyethyl methacrylate in aqueous solutions, as influenced by pH, temperature, and substrate concentration, was studied. In concentrated solutions, the monomer forms associates, which promotes its hydrolysis.     

N-乙烯基甲酰胺-丙烯腈共聚

以功能单体N-乙烯基甲酰胺与丙烯腈共聚,制备可转化为对重金属离子具有吸附能力的螯合物。深入计论了聚合机理,以及单体配比、单体舍量、引发剂舍量、反应温度、反应时间对聚合物转化率、特性粘数的影响。聚合动力学研究表明,该共聚几乎没有诱导期,反应初期匀速阶段较长,其转化率接近30％,自动加速不明显。运用FTIR对结构进行了表征,确立了反应的较佳条件。     

Simulation of Industrial Processes Involving Concentrated Aqueous Solutions

The Pitzer model is applied to simulate various single- and multistage modifications of the industrial conversion process

Complexation of Calcium Ions with Dicarboxylic Acids in Aqueous Solutions

Complexation of calcium ion with malonic, succinic, glutaric, adipic acids at 25°C, ionic strength I = 0.3 (KCl) was studied by pH-potentiometric titration.     

丙烯酰胺-N-羟甲基丙烯酰胺反相乳液共聚合

：以Ｓｐａｎ ４０ 为乳化剂,过硫酸铵为引发剂,进行了丙烯酰胺 Ｎ 羟甲基丙烯酰胺反相乳液共聚反应,研究了反应温度、单体浓度、引发剂浓度、乳化剂浓度等因素对聚合动力学的影响,并讨论了其聚合机理。     

Phase Behavior and Rheological Properties of Concentrated Lecithin Aqueous Solutions with Additives

The phase behavior and rheological properties of the concentrated lecithin aqueous solutions were investigated at 37°C. When adding Isopropyl myristate (IPM) to lecithin solutions, besides an anisotropic liquid crystal (LC) phase, an isotropic liquid (L₂) region and an isotropic viscous (I) phase are found. By continuously adding Brij 97, the LC region shifts towards higher water content and the L₂ region is extended to the area of lower IPM concentration, meanwhile the I phase disappears. By analyzing the shear rate (η_γ=0.1) and yield stress (σ₀), adding IPM to lecithin solutions increases the values of η_γ=0.1 and σ₀, and after further adding Brij 97, the η_γ=0.1 and σ₀ decrease dramatically. Notably, different from the lecithin/DDAB/water system studied by Youssry and Montalvo, in lecithin/Brij 97/IPM/H₂O system, at the relatively higher water content area of the LC phase, the water content has little effect on the critical stress. It is also found that the change of dynamic storage modulus (G′) is similar with that of η_γ=0.1 and σ₀ parameters when adding IPM and Brij 97. Maxwell model fitting results show that in the LC phase, the relaxation of the water molecule is prolonged by adding IPM and Brij 97 to lecithin solutions.     

分光光度法测定水溶液中的有机酸含量

利用水溶液中的有机酸在高氯酸羟胺(HAP)和N,N′-二环己基碳酰亚胺(DCC)存在的条件下生成的羟肟酸,以及羟肟酸在酸性高氯酸铁溶液中显色的性质,建立了一种分光光度测定水中有机酸含量的方法。对显色剂的酸度、浓度、加入体积、HAP和DCC的浓度、加入体积以及显色反应的温度、反应时间对吸光度的影响进行了考察。结果表明,该显色反应在反应条件:0.0687mol/LHAP1.0mL、0.6mol/LDCC0.5mL、震荡均匀后室温下放置反应15min、0.02mol/L酸性高氯酸铁溶液(高氯酸浓度0.3mol/L)显色条件下具有最大的吸光度;并对正丁酸、正戊酸、苯甲酸进行了线性关系考察。结果表明,该检测方法具有仪器简单、操作方便、线性范围较宽、准确度高等优点,可用于那些不易从水溶液中萃取的有机酸的测定,也可用于液相色谱洗脱液中有机酸的测定。     

Formation of Cyclic Oligomers in Concentrated Aqueous Solutions of Formaldehyde

An MNDO calculation gave the formation enthalpies of the components of equilibrium mixtures in concentrated aqueous acid solutions of formaldehyde. The results of this study suggest that intramolecular cyclization of linear oligomers with 5 and 9 CH₂O units, respectively, is the most plausible mechanism of formation of cyclic oligomers of formaldehyde — trioxane and tetraoxane. Ring protonation by the hydroxonium ion with ring opening is the most energetically favorable route of cyclic acetal decomposition.     

Interactions of D-Maltose and Sucrose with Some Amino Acids in Aqueous Solutions

Calorimetric titrations have been performed at 298.15 K in aqueous solutions to derive the stability constants and thermodynamic parameters of the interactions of D-maltose and sucrose with some amino acids (glycine, DL-alanine, DL-leucine, and L-serine). The apparent molal volumes of the disaccharides in dilute aqueous solutions of the amino acids have been determined from density measurements at 298.15 K. In contrast to D-maltose, sucrose was found to associate with the amino acids and these associated species are preferentially entropy stabilized. These results are interpreted in terms of the influence of the nature of the solutes, their specific conformations, and hydration, on the ability of the disaccharides to form associated complexes with the amino acids.