Self-assembly and influence of the organic counterion in the ternary systems dodecylamine/acrylic acid/water and dodecylamine/methacrylic acid/water

Due to complete proton transfer from the acid to the amine, a reaction between an equimolar mixture of dodecylamine and (meth)acrylic acid leads to the formation of dodecylammonium (meth)acrylate. The latter can be considered as a surfactant with a polymerizable organic counterion. The ternary phase diagrams of the two systems dodecylamine/acrylic acid/water and dodecylamine/methacrylic acid/water are described. Both systems can form isotropic solutions and lyotropic liquid crystalline lamellar phases. Moreover, the system with the methacrylate counterion can also form a cubic phase in the water-rich part of the phase diagram. The difference in the self-organization observed for the two systems is explained by the greater bulkiness and hydrophobicity of the methacrylate. Whereas the acrylate counterion behaves rather like a classic inorganic counterion, the methacrylate counterion resides in the outermost part of the aggregates, giving rise to a change in the surface curvature.     

热诱导相分离法制备亲水性乙烯-丙烯酸共聚物微孔膜

选择 3种不同丙烯酸含量的乙烯 丙烯酸共聚物 (EAA)为原材料 ,二苯醚 (DPE)为稀释剂 ,采用热诱导相分离法 (TIPS)制备了亲水性高分子微孔膜 .接触角实验证明 ,EAA为亲水性高分子材料 .利用熔点仪根据浊度的变化测绘出 3种不同EAA/DPE体系的双结点线以及通过DSC得出相应 3体系的结晶温度曲线 .实验结果还表明 ,随着乙烯 丙烯酸共聚物中丙烯酸含量的增加 ,结晶温度曲线向低温方向移动 ,相对应的膜孔直径也增加 .此外 ,随着EAA DPE体系中EAA初始浓度的逐渐增加 ,膜孔直径逐渐变小 ,当体系中EAA初始浓度高于 5 0 %时 ,不再出现微孔结构     

Blends of styrene/acrylic acid copolymers and acrylic polymers

The miscibility of a series of styrene/acrylic acid copolymers with various polyacrylate and polymethacrylate homopolymers, as well as a series of styrene/methyl methacrylate copolymers, has been investigated. According to the binary interaction model, the miscibility diagram for styrene/acrylic acid copolymers with styrene/methyl methacrylate copolymers indicates that acid and ester groups interact endothermically. The phase behavior of the homopolymers also implies this. The analysis ignores the association and self-association observed for the polymer blends and the low-molecular-weight analogs used to model them. The heat of mixing of low-molecular-weight analogs depended greatly on both composition and acid structure.     

Selective oxidation of propane to acrylic acid over mixed metal oxide catalysts

The effects of metal atomic ratio, water content, oxygen content, and calcination temperature on the catalytic performances of MoVTeNbO mixed oxide catalyst system for the selective oxidation of propane to acrylic acid have been investigated and discussed. Among the catalysts studied, it was found that the MoVTeNbO catalyst calcined at a temperature of 600 ℃ showed the best performance in terms of propane conversion and selectivity for acrylic acid under an atmosphere of nitrogen. An effective MoVTeNbO oxide catalyst for propane selective oxidation to acrylic acid was obtained with a combination of a preferred metal atomic ratio （Mo1V0.31Te0.23Nb0.12）. The optimum reaction condition for the selective oxidation of propane was the molar ratio of C3H8 ：O2 ： H2O ： N2 = 4.4： 12.8 ： 15.3 ： 36.9. Under such conditions, the conversion of propane and the maximum yield of acrylic acid reached about 50% and 21%, respectively.     

Small Angle X‐ray Diffraction Studies for Hydrophobically Modified Polyelectrolytes

Sulfonate anion modified acrylic acid ter‐polymers and [2‐(methacryloyloxy)ethyl] trimethyl‐ammonium chloride cation modified acrylic acid polymers have been prepared and were characterized with small angle x‐ray diffraction studies. While the sulfonate anion modified acrylic acid ter‐polymer solutions exhibit strong scattering at an angle corresponding to a scattering vector 0.016 A^?1, the cation modified acrylic acid polymers show no scattering at corresponding concentrations. The anion modified acrylic acid ter‐polymers are more compact than the corresponding cation‐modified acrylic acid polymers.     

Copolymerization of acrylic and methacrylic acids with N-vinylpyrrolidone

The copolymerization of an acidic monomer (acrylic or methacrylic acid) and a basic monomer (N-vinylpyrrolidone) (NVP) is investigated. Various physical measurements revealed a strong molecular interaction between the two monomers. However, the resulting association complex does not seem to control the copolymerization. A slight solvent effect is observed with dimethylformamide for the acrylic acid-NVP system. Methacrylic acid appears to be much more reactive than acrylic acid in its copolymerization with NVP. The results obtained with methacrylic acid-NVP system conflict with earlier published results.     

丙烯酸在炭黑表面接枝聚合研究

丙烯酸在炭黑表面接枝聚合研究吴壁耀，刘安华，邵兰英，蒋子铎（武汉化工学院精细化工系，武汉，４３００７３）关键词接技聚合，炭黑，Ｚｅｔａ电位，表面改性炭黑是由大量的原生粒子聚集而成的．该聚集体表面积大、表面又含有丰富的极性基因，故在炭黑／涂料树脂体系中...     

Study on modification of polymers with the aid of the Schmidt reaction

A study of the Schmidt reaction on several polymers with pendant carboxylic and ketone moieties was carried out. Four polymers were used as starting materials: (1) poly(methyl vinyl ketone), (2) poly(acrylic acid), (3) a copolymer of methyl vinyl ketone and acrylic acid, and (4) a copolymer of styrene and acrylic acid. Most reactions were conducted in an acetic acid medium with the exception of one reaction on poly(acrylic acid) which was done in dioxane and another on copolymer of styrene and acrylic acid done in chloroform. It was found that a Schmidt reaction on poly(acrylic acid) in acetic acid solution will lead to intermolecular reactions of the intermediate with the solvent in preference to reactions with neighboring carboxyl groups on the polymer backbone. A tendency of poly(acrylic acid) to form cyclic anhydrides under these reaction conditions interferes with the yield of acetamide units.     

Electrochemical copolymerization of N-vinylazoles with acrylic acid at iron and copper electrodes

Possibility of electrochemical synthesis of polymeric coatings based on copolymers of 1-vinyl-1,2,4-triazole and 1-vinylimidazole with acrylic acid at iron and copper electrodes with aryldiazonium salt as initiator has been demonstrated. Dielectric properties of the so prepared polymeric coatings have been studied. Degradation of 1-vinylimidazole copolymers with acrylic acid has been slower than that of other acrylic acid copolymers.     

Efficient water‐soluble drag reducing star polymers with improved mechanical stability

We describe here the first example of the synthesis of 4‐arm star poly(acrylic acid) for use as a water‐soluble drag reducing agent, by applying Cu(0)‐mediated polymerization technique. High molecular weight 4‐arm star poly(tert‐butyl acrylate) (M_n = 3.0–9.0 × 10⁵ g mol^?1) was first synthesized using 4,4′‐oxybis(3,3‐bis(2‐bromopropionate)butane as an initiator and a simple Cu(0)/TREN catalyst system. Then, 4‐arm star poly(tert‐butyl acrylate) were subjected to hydrolysis using trifluoroacetic acid resulting in water‐soluble 4‐arm star poly(acrylic acid). Drag reduction test rig analysis showed 4‐arm star poly(acrylic acid) to be effective as a drag reducing agent with drag reduction of 24.3%. Moreover, 4‐arm star poly(acrylic acid) exhibited superior mechanical stability when compared with a linear poly(acrylic acid) and commercially available drag reducing polymers; Praestol and poly(ethylene oxide). The linear poly(acrylic acid), Praestol, and poly(ethylene oxide) all showed a large decrease in drag reduction of 8–12% when cycled 30 times through the drag reduction test rig while, in contrast, 4‐arm star poly(acrylic acid) demonstrated much higher mechanical stability. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 335–344     

高锰酸钾—硫脲体系引发丙烯酸接枝共聚尼龙的研究

研究了以高锰酸钾和硫脲组成的氧化还原引发体系,在水介质中,引发丙烯酸接枝共聚尼龙的共聚反应。考察了丙烯酸浓度、引发剂浓度及温度等因素对接枝共聚反应的影响。红外光谱分析和Ｘ射线衍射图谱证明了接枝反应的存在及对聚合物结晶度的影响。     

Radiation-induced solid-state polymerization in binary systems. II. Relationship between polymerization rate and physical structure of binary systems

The radiation-induced solid-state polymerization of binary systems consisting of acrylic monomer (acrylamide, acrylic acid) and organic compounds was investigated. In the previous paper on binary systems the authors reported that the rate of polymerization increased in the solid state (eutectic mixture systems). The mechanism of rate increase has been investigated by examination of phase diagrams, viscosities, and surface tension of the binary systems. Viscosity and surface tension are the measure of the molecular interaction of the two-component systems. In addition, the effect of linear crystal growth rate and half maximum width of the x-ray diffraction diagram of the crystallization process were determined. The larger the molecular interaction between the two components, the slower the linear crystal growth rate of monomer. The size of the monomer crystal decreases and the dislocation density of the monomer crystals increases in systems with large molecular interaction. Consequently it can be concluded that the physical structure of a binary solid system is the most important parameter determining the rate increase of solid-state polymerization. Dislocation on the grain boundary is more important than defects inside of the crystal lattice. It was found that the acceleration of polymerization rate is large in binary systems with larger molecular interaction. In some systems such as organic acid—amide systems with strong hydrogen bonds, glassy phases may be formed in which monomer may readily polymerize at very low temperatures.     

Sequential Dehydration and Oxidation of Biodiesel-derived Crude Glycerol into Acrylic Acid

With the fast development of the biodiesel industry, the byproduced crude glycerol becomes excessive due to the limited demand for refined glycerol. This article provides a green and efficient route to produce acrylic acid from crude glycerol, which is a promising alternative and complement to the petroleum-based production of acrylic acid due to its economic and environmental benefits. Among all the impurities, only the alkaline metal ions in crude glycerol significantly decreased the yield of acrylic acid. After desalination of the plant crude glycerol with ion-exchange resin to remove the critical impurities, the sequential dehydration and oxidation system gave 86% acrylic acid yield, which was as high as that with pure glycerol. In addition, the system showed good thermal stability and regeneration ability after the reaction with desalted crude glycerol. Both the HPW/Cs–Nb and VMo–SiC catalysts were stable for at least 70 h. The activity and selectivity were well recovered after regeneration at the coke burning temperature of 500°C.     

Effect of poly(acrylic acid) block length distribution on polystyrene-b-poly(acrylic acid) block copolymer aggregates in solution. 2. A partial phase diagram

The first paper of the series, which focused on the effect of polydispersity on the self-assembly of block copolymer vesicles, showed that an increase in the width of the poly(acrylic acid) (PAA) block length distribution resulted in a decrease in the size of the vesicles formed. In this paper, the rest of the phase diagram is explored. For the present study, a series of polystyrene-b-poly(acrylic acid) copolymers of an identical polystyrene length of 325 units but of varying degrees of polymerization of PAA was synthesized. Mixtures of the copolymers were made to artificially broaden the molecular weight distribution of PAA at a constant number average of 48 in the polydispersity index (PDI) range of 1.1-3.3. The mixtures were dissolved in dioxane, and water was added slowly to predetermined amounts. Transmission electron microscopy was used to observe aggregate morphologies at different water contents and PAA PDIs. At low water contents, dynamic light scattering was also used to measure the sizes of the aggregates. A partial phase diagram as a function of the water content and PAA PDI was obtained. Large compound micelles and spherical micelles (average diameter of 40 nm) were found at low water contents; however, at a water content of 12% (w/w), a continuum of morphologies from spheres to rods to vesicles was found with increasing PAA PDI. In addition, each copolymer was investigated by itself under identical conditions to those used for the mixtures to determine if there was any segregation of the individual polymers into separate aggregates. No evidence for such segregation was found.     

Double-polyelectrolyte, like-charged amphiphilic diblock copolymers: swollen structures and pH- and salt-dependent lyotropic behavior

We consider a symmetrical poly(styrene- stat-(acrylic acid))- block-poly(acrylic acid), i.e., PSAA- b-PAA, diblock copolymer, with a molar fraction phi AA = 0.42 of acrylic acid, in the more hydrophobic PSAA statistical first block. We investigate its structural behavior at constant concentration in water using small-angle neutron scattering (SANS) by varying (i) the ionization of its acrylic acid motives via the pH by adding NaOH and (ii) the ionic strength of the solution by increasing the NaCl salt concentration c S. We present the resulting morphological phase diagram {pH, c S}, in which we identified two different lamellar phases presenting a smectic long-range order at small-to-intermediate ionizations and a spherical phase with a liquid-like short-range order at larger ionization. In the low-ionization regime, the first lamellar phase comprises a water-free PSAA lamellar core surrounded by a dense poly(acrylic acid) brush swollen with water. Its mostly hydrophobic core still being glassy, this phase is unable to reorganize and is frozen in. A detailed analysis of the SANS data shows the osmotic nature of the polyelectrolyte brush, in which the Na+ counterions are confined so that local electroneutrality is satisfied. Above the pH at which the PSAA statistical block starts ionizing, the PSAA lamellar core melts. The second lamellar phase identified then comprises a PSAA core thinner than that of the frozen-in previous phase, implying a significant increase of the core/water interface and a decrease of the brush surface density. The transition from the first lamellar phase to the second one can be quantitatively shown to result from the balance between the two contributions: (i) the extra interfacial cost between the thinner core and water and (ii) the associated gain in entropy of mixing for the counterions confined inside the brush. At even higher ionization, the diblocks finally form spherical objects with a very small, pH-dependent aggregation number and reach an apparent onset of self-association. When the highest ionization investigated is reached, the cores of these final spherical core-shell objects are found to contain a significant amount of water. We thereby demonstrate that at constant concentration, pH, and ionic strength both trigger a transition from frozen to molten hydrophobic phases as well as unexpected morphological transitions.     

高分子药物－可乐定阴离子丙烯酸树脂盐的研制及释药性能探索

研制了高分子药物－可乐定阴离子丙烯酸树脂盐并在模拟胃和小肠ｐＨ的缓冲液中进行了高分子药物的溶解释放试验。结果表明其中某些试样能够在微碱性的缓冲液中缓慢溶解释放，可望达到减少用药量。降低副作用和延长药效的目的。     

Synthesis of new heterocyclic ring systems. Reaction of indolines and hexahydrocarbazole with α,β-unsaturated acids

Reactions of indoline (I), 2-methylindoline (II) and hexahydrocarbazole (III) with α,β-unsaturated acids in the presence of polyphosphoric acid have been investigated. Reaction of 1 with acrylic acid afforded two compounds which were identified as 1,2,4,5-tetrahydro-6H-pyrrolo-[3,2,1-ij] quinolin-6-one (IV) and 2,3,5,6,9,10-hcxahydro-1H-cyclopenta[f lpyrrolo [3,2,1-ij|-quinoline-1,8-dione (VII). The reaction oi 1 with crotonic acid gave compounds V and VIII, analogous-to IV and VII. The reaction of II with acrylic acid yielded two compounds VI and IX, whereas with crotonic acid, only X was isolated. With 111, acrylic acid afforded 5,6,8,9,10. 11,8a,11a-octahydro-4H-pyrido[3,2,1-jk]carbazol-4-one (XI) and a compound with a heretofore unknown ring system, viz., 2,3,5,6,7,8,11,12,5a,8a-decahydro-1H-cyclopenta[h] pyrido [3,2,1-jk |earbazole-1,10-dione. The structures of these compounds were deduced on the basis of their spectral and analytical data.     

Optimization of Functional Monomer Content in Protein‐Imprinted Polymers

Abstract

We have prepared synthetic materials having binding specificity toward lysozyme using molecular imprinting. The lysozyme‐imprinted polymers were prepared on silica beads using acrylic acid, acrylamide, and N,N′‐methylenebisacrylamide. The molar ratio of acrylic acid to the template affected the selectivity and the maximum binding specificity was yielded with the molar ratio of 5 to 1 (acrylic acid/template). No binding specificity toward lysozyme was observed when there was no acrylic acid, and the binding specificity decreased when the amount of acrylic acid was high. The functional monomer‐template ratio indicated in this study could be useful for improving the binding specificity in molecular imprinting of proteins.     

Effect of complexation of poly(acrylic acid) with Cu2+ ions on the size of copper nanoparticles prepared via reduction in aqueous solutions

Sols of zero-valence copper are prepared via the chemical reduction of Cu(II) ions by hydrazine borane in aqueous solutions of high-molecular-mass poly(acrylic acid), which forms stable complexes with copper ions at 20°C in a wide pH range. The study of the composition of coordination centers, the ligand surrounding of metal ions, and the character of distribution of copper ions over poly(acrylic acid) coils in a wide range of solution compositions and pH values shows that the size of copper nanoparticles in the sols can be controlled by varying the ratio between ligand groups (carboxylate anions in poly(acrylic acid)) and copper ions in the reaction system during the synthesis of sols. This effect can be accomplished either by variation in the initial composition of solution or change in pH (the degree of ionization of the initial poly(acrylic acid) in the presence of copper ions).     

还原性气氛对丙烷选择氧化催化剂Mo-V-Te-Nb-O结构及活性的影响

系统地研究了还原剂(氯化铵)添加到丙烷选择氧化合成丙烯酸催化剂Mo-V-Te-Nb-O混合氧化物中对催化剂性能的影响.实验结果表明,在制备过程中还原剂的存在明显地影响了所得催化剂晶格氧的活动性,而晶格氧的活动性对Mo-V-Te-Nb-O混合氧化物的催化活性有重要的影响.进一步的研究表明,添加还原剂引起了催化剂形貌和相组成的变化,这些对于丙烯酸的形成有着重要作用.具有较多M1相含量的催化剂在低温(<653 K)时表现出了高丙烯酸选择性,而具有较多M2相含量的催化剂则在高温(>653 K)时更有利于丙烯酸的生成.