A fluorine-containing hydrophobically associating polymer. I. Synthesis and solution properties of copolymers of acrylamide and fluorine-containing acrylates or methacrylates

Fluorine-containing hydrophobically associating polymers have been synthesized by copolymerization of acrylamide with a small amount of an acrylate or methacrylate having a fluorocarbon containing ester group. It was found that hydrophobic associations occurring between these fluorocarbon chains was stronger than the interactions of the corresponding hydrocarbon comonomers and depend on the length of the fluorocarbon chain. The rheological properties of the copolymer solutions were studied. The solutions were found to be highly pseudoplastic but the viscosity loss was completely reversible upon removal of shear. Evidence for hydrophobic association of the fluorocarbon groups was obtained by the dependence of the Brookfield viscosity on temperature, the addition of NaCl, and the addition of organic solvents, urea, and surfactants.     

孪尾疏水缔合丙烯酰胺/丙烯酸钠/N,N-二辛基丙烯酰胺共聚物的合成与性能

孪尾疏水缔合丙烯酰胺/丙烯酸钠/N; N-二辛基丙烯酰胺共聚物的合成与性能;孪尾;胶束聚合;水溶性聚合物;疏水缔合;合成;粘度     

Dansylated acrylic copolymer with potential for sensor applications: Synthesis and properties

A novel copolymer has been prepared by free radical polymerization in dimethylformamide of 5‐dimethylamino‐1‐(β‐methacryloyloxyethylcarbamoyloxyethyl)‐N‐methylsulfonamido‐naphthalene (Dns‐Acr) and methyl methacrylate in 1:3 M ratio with azobis(isobutyronitrile) as the initiator. The structure, purity, and the chemical composition of the dansylated copolymer (Dns‐COPA) were confirmed by spectrophotometric (¹HNMR, FTIR, UV/vis), thermal and analytical methods, GPC measurements, and AFM techniques. Compared with Dns‐Acr, whose fluorescence emission band appears at 510 and 430 nm (shoulder), the photoluminescence spectrum of the Dns‐COPA in DMF solution exhibited a strong fluorescence emission at 440 nm (I₁), and a small shoulder at 520 nm (I₂) accompanying the main signal. The emitting behavior of Dns‐COPA was investigated through a spectrofluorimetric titration experiment, the fluorescence measurements demonstrating that introduction of various acids into the solution has a significant effect upon the quenching of fluorescence. This ability of dansyl copolymer to suffer the protonation of the amino group in organic acidic phase may be exploited in sensor applications. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3774–3782, 2008     

Synthesis of silicone–acrylate copolymer latexes and their film properties

Emulsion copolymerization of silicones (octomethyl tetracyclosiloxane, D₄ and methacryloxypropyl trimethoxy silane, MATS) and acrylics was carried out using three different polymerization processes: semicontinuous monomer emulsion addition, batch and initiator solution addition. Results showed that only the semicontinuous process led to a stable latex with monodisperse particles. Various polymerizations were carried out through this process with varying silicone/acrylic ratios and MATS content. Films were obtained from different latexes: their properties are significantly influenced by silicone and MATS contents in copolymers.     

苯乙烯一氧化碳高聚物的合成与表征

阳离子钯-配体催化剂的的存在下,一氧化碳与烯烃的均相共聚形成新型环保材料聚酮,共聚单体一氧化碳价格低廉,生成的共聚物主链上存在具有反应活性的羰基官能团,与烯烃均聚物比较,具有光降解性能以及生物降解性能,     

Synthesis of a soluble pyrrole copolymer with phenetidine

A new series of copolymers was synthesized through the oxidative polymerization of pyrrole (PY) and o‐phenetidine (PHT) with inorganic oxidants in acidic media. The polymerization parameters including the mixing method of the oxidant with the comonomer, the comonomer ratio, the time, the temperature, the oxidant, the organic medium, and the acid were systematically optimized for the synthesis of copolymers with high yields, intrinsic viscosities, and solubility. The resultant copolymers were characterized by elemental analysis, infrared, ultraviolet–visible, solution high‐resolution ¹H NMR and solid‐state high‐resolution ¹³C NMR, circular dichroism spectroscopy, and cyclic voltammetry. The results showed that the PY observed content in the copolymers was much higher than the PY feed content. The regular variation of the polymerization yield, intrinsic viscosity, solubility, macromolecular structure, and electroactivity of the resulting polymers with the comonomer ratio, together with the complete solubility of a PY/PHT (10/90) polymer in highly polar solvents, indicated the formation of real random copolymers containing both PY and PHT units rather than a mixture of two homopolymers. However, the polymers containing more than 59 mol % PY were not homogeneous copolymers consisting of soluble and insoluble parts. A semiquantitative relationship between the polymerization yield or solubility of the copolymers and the polarity index of the organic solvents was examined. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2073–2092, 2004     

疏水缔合水溶性聚合物的合成研究进展

综述了疏水缔合水溶性聚合物的合成的最新研究进展。主要合成方法有非均相共聚、均相共聚、胶束共聚、反相微乳液聚合、无皂乳液聚合、活性阴离子聚合以及超临界二氧化碳介质等。     

疏水缔合水溶性聚合物P(AM/NaAA/DiAC16)的合成与性能

以双烯丙基胺和1-溴代十六烷为原料合成了疏水单体N,N-双烯丙基十六胺,采取前加碱二元胶束共聚-后水解法合成了三元疏水缔合水溶性聚合物聚(丙烯酰胺/丙烯酸钠/N,N-双烯丙基十六胺)[P(AM/NaAA/DiAC16)],用FTIR、1H-NMR进行了结构表征;以芘为荧光探针,利用稳态荧光光谱法、粘度法研究了P(AM/NaAA/DiAC16)在水溶液的缔合行为.当x(DiAC16)=0.10～0.40 %时,在30℃、1mol·L-1NaCl溶液中,其Huggins常数KH小于0.80(144～0.294),表明稀溶液中缔合作用较弱.随聚合物浓度、疏水单体用量的增加,P(AM/NaAA/DiAC16)在二次蒸馏水中、1.000 mol·L-1 NaCl水溶液中,I1/I3值减少;在矿化度为19 334 μg/g盐水溶液中,水溶液的表观粘度增加、临界缔合浓度降低.结果表明,P(AM/NaAA/DiAC16)缔合行为取决于聚合物浓度、疏水单体用量及介质的极性.     

On the properties of surfactant aqueous solutions

Summary From studies of aqueous solutions of dodecylammoniumnitrate an association mechanism has been proposed involving multiequilibrium. In the concentration range considered we can differentiate between two aspects: ranges of marked qualitative and quantitative changes and formation of differently structured surfactant species.

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Zusammenfassung Aus der Untersuchung wäßriger Lösungen von Dodecylammoniumnitrat würde ein Assoziationsmechanismus abgeleitet, welcher ein Multiequilibrium beinhaltet. Im untersuchten Konzentrationsbereich können zwei Bereiche unterschieden werden: Bereiche mit ausgeprägten qualitativen und quantitativen Änderungen und Bereiche mit der Bildung von verschieden strukturierten oberflächenaktiven Spezies.

     

The scaled-particle theory and solvent isotope effects on the thermodynamic properties of inert solutes in water and methanol

The scaled-particle theory has been applied to the calculation of the thermodynamic changes associated with the formation of a cavity in several isotopic varieties of liquid water and methanol. From these results, the thermodynamic functions for the transfer of a cavity (or a hard-sphere solute) have been computed for the following solvent pairs: H₂OD₂O, H₂OH₂ ¹⁸O, H₂ ¹⁸OD₂ ¹⁸O, D₂OD₂ ¹⁸O, CH₃OHCH₃OD. For the last two of these solvents, density measurements required for the calculations were carried out as a function of temperature. The calculated deuterium solvent isotope effect on the heats and entropies of hard-sphere solutes in water is much greater than the¹⁸O isotope effect; the former also exhibits a more pronounced temperature dependence. The transfer functions computed for hard-sphere solutes are compared to experimental data on the transfer of various solutes from H₂O to D₂O and from CH₃OH to CH₃OD. In most of the cases examined, the cavity effect accounts for a large part of the transfer quantities measured for rare gases, hydrocarbons, and solutes containing a significant hydrocarbon substituent.     

Synthesis of a novel phosphate‐containing highly transparent PMMA copolymer with enhanced thermal and flame retardant properties

A novel poly(methyl methacrylate) (PMMA)‐based copolymer (PMMA‐co‐BDPA) rich in aromatic rings was synthesized via radical copolymerization between a phosphorus‐containing acrylic monomer (BDPA) and methyl methacrylate (MMA). UV‐vis spectroscopy demonstrated that the copolymer had high transparency. Thermogravimetric analysis (TGA) and a differential scanning calorimeter (DSC) were used to test the thermal properties of the composites. Additionally, the PMMA‐co‐BDPA‐15 copolymer exhibited a 23% increase in the limited oxygen index (LOI) value. A cone calorimeter test indicated that the peak heat release rate (pk‐HRR) of PMMA‐co‐BDPA was reduced by 29.2% compared with that of pure PMMA, and the carbon yield of burning was obviously increased. The combined test results demonstrated that the prepared copolymer material had good transparency, thermal stability, and flame retardancy.     

Synthesis of Pd catalysts based on a nonbornene−CO copolymer and their properties in the carbomethoxylation of propylene

It was found that carboxylation of norbornene (nbn) in the presence of the PdCl₂−PPh₃−HCl catalytic system is accompanied by alternating copolymerization ofnbn with carbon monoxide to form norbornanecarboxylic acid (yield ∼20%) and anbn-CO copolymer (yield ∼80%,M _w=1600,M _w/M _n=1.6). The Pd^II salt of poly(norbornaneketone)carboxylic acid is a highly active catalyst for the carbomethoxylation of propylene. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 368–370, February, 1998.     

Bulk and microscopic properties of copolymer networks in mixed aqueous solvents

Amphiphilic films and hydrogels have been prepared from ethanol/water solutions containing a hydrocarbon-grafted water-soluble cellulose ether. These materials are characterized by dispersed hydrophobic microdomains which form spontaneously in the solvent due to the inherent incompatibility of the side chains with water. At low applied shear stress, the microdomains behave as temporary linkages of finite lifetimes, imparting viscoelastic properties to the networks. The molecular weight between microdomains was found to be independent of the volume fraction of polymer in the gel, and the number of linkages per backbone ranges from 22.8 ± 1.3 to 26.2 ± 1.5 over the frequency range 30–50 rad/s. The behavior of the solutions and gels was characterized using fluorescence and dynamic rheological measurements. It was demonstrated that the microdomains are capable of sequestering water-insoluble solutes. © 1992 John Wiley & Sons, Inc.     

Hydrophobically modified polyelectrolytes III. Reactivity ratio determination of FX14/AA,LA/AA and SA/AA

The reactivity ratios of three hydrophobic monomers, FX14, LA and SA, to hydrophilic monomer, acrylic acid (AA), were determined. For the fluorocarbon containing hydrophobic monomer FX14, elemental analysis was adopted to obtain the relative content of FX14 to AA. For two hydrocarbon monomers, ¹³C NMR was used. FR, KT linear method and EVM nonlinear method were applied in calculating reactivity ratios. It is found that the reactivity of LA and SA is lower than that of AA, for solution polymerization in cyclohexane. Whereas FX14 is more reactive than AA in benzene. Finally, the distribution of small amounts of these hydrophobic monomers along the polymeric chain is discussed and a random sequence is confirmed     

Synthesis and properties of amphoteric copolymer of 5‐vinyltetrazole and vinylbenzyl phosphonic acid

Amphoteric polymers have been studied for various applications such as separation of low molecular weight organic molecules from inorganic salt mixtures, selective ion transport, drug delivery through membranes of biological interest, separation of ionic drugs and proteins, and separation of alcohol and water. Typical amphoteric polymers consist of weak base and weak acid groups. In present study, the copolymerization of 5‐vinyltetrazole (VT) and diisopropyl‐p‐vinylbenzyl phosphate (DIPVBP) via free radical polymerization is studied. The reactivity ratio of VT and DIPVBP, which is calculated from Kelen‐Tudos plot, is 0.251 and 0.345, respectively. The amphoteric copolymer of VT and diisopropyl‐p‐vinylbenzyl phosphonic acid (poly(VT‐co‐VBPA)) is obtained from hydrolysis of the copolymer of VT and DIPVBP (poly(VT‐co‐DIPVBP)). Poly(VT‐co‐VBPA) is thermally stable under 190 °C. The anhydrous proton conductivity of amphoteric poly(VT‐co‐VBPA) can reach 1.54 × 10^‐4 S cm^?1 at 170 °C with an activation energy of 114.7 kJ mol^?1. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3486–3493     

高强度疏水缔合水凝胶的交联网络结构形成机理

高强度疏水缔合水凝胶(HA-gels)是丙烯酰胺(AM)和少量的疏水单体辛基酚聚氧乙烯(4)醚丙烯酸酯(OP-4-AC)在十二烷基硫酸钠(SDS)水溶液中采用胶束共聚的方法制备的.采用胶束共聚理论、橡胶弹性统计理论及Mooney-Rivlin理论,并结合单向拉伸实验数据,对HA-gels的交联网络结构的形成机理进行了探...     

Swelling and drug releasing properties of poly(N-isopropylacrylamide) thermo-sensitive copolymer gels

A series of N-isopropylacrylamide (NIPAAm) copolymer gels with different hydrophilicities were prepared from NIPAAm, hydrophilic acrylamide (AAm) and hydrophobic butyl methacrylate (BMA). The swelling and thermo-responsive properties of PNIPAAm P (NIPAm-co-BMA) and P(NIPAm-co-AAm) copolymer hydrogels were investigated. The drug loading and releasing behaviors for two kinds of model drug with different hydrophilicities were studied. The result shows that the copolymer gels present negative thermo-sensitivities. The lower critical solution temperature (LCST), equilibrium swelling degree and the initial swelling rate increase as the hydrophilicity of gels increases when the temperature is below the LCST. With increasing gel hydrophilicity the loading ratio for sodium salicylate increases, while for salicylic acid, the reverse is observed. The initial drug releasing rate of sodium salicylate and salicylic acid also increase with increasing gel hydrophilicity. The initial drug releasing rate of sodium salicylate is significantly higher than that of salicylic acid. For salicylic acid which is less hydrophilic, the equilibrium releasing ratio at high temperature is lower than that at low temperature while for sodium salicylate which is more hydrophilic, the equilibrium releasing ratio at high temperature is almost the same as that at low temperature. Equilibrium releasing ratios of the three gels are significantly different from each other for salicylic acid when the temperature is below LCST while the equilibrium releasing ratios of the three gels are all 100% for sodium salicylate. __________ Translated from Journal of Central South University (Science and Technology), 2007, 38(5): 906–911 [译自: 中南大学学报(自然科学版)]     

A near-infrared study of the hydration of various ions and nonelectrolytes

The differential infrared absorption spectra of H₂O at 1200 nm and HOD/D₂O at 1450 nm have been recorded as function of temperature between 2 and 55°C. Following earlier investigations in the 1000 nm region,^(1,2) the data were interpreted on the basis of a hydrogen-bonding equilibrium invoking two states of the OH oscillators which are found to differ by a van't Hoff heat of formation of 2–3 kcal-mole^–1. The spectral changes induced by various non-electrolytes (1.0m) on the 1000 nm band have been recorded at 25°C for the following: tetrahydrofuran, tetrahydropyran, dioxane, dimethoxyethane, dimethyl sulfoxide, acetone, methyl acetate, propylene carbonate, dimethylformamide, dimethylacetamide, tetramethylurea, acetonitrile, and nitromethane. The specific influence of hydrocarbon chains on the near-IR absorption spectrum of water was further studied using a series of homologous sodiumn-alkyl carboxylates (formate to octanoate). The differential solvation spectra of three azoniaspiroalkane bromides have been obtained to compare the relative effects of cyclic and linear alkyl substituents. Finally, the study of ionic hydration effects has been extended to include the following electrolytes: NaPF₆, NaClO₄, NaBF₄, NaClO₃, NaNO₃, NaBrO₃, NaCN, NaSCN, Na₂SO₄, Na₂SO₃, Na₂CO₃, Na₂S₂O₃, MgCl₂, CaCl₂, BaCl₂, and SrCl₂. These data are discussed in terms of perturbations of the hydrogen-bonding equilibrium in water originating from one of the following: (1) direct OH... [polar group or anion] interactions, (2) structure-breaking effects due to weak OH... solute interactions, and (3) water-structure-promoting effects by alkyl groups.     

Ion association in lithium metaborate solution: a Raman and ab initio insight

Ion association and hydration clusters in aqueous lithium borate solution are extremely important to understand some extraordinary properties of lithium borates. In the present work, polyborate distribution in aqueous LiBO₂ solution was investigated through Raman and thermodynamics equilibrium analysis. Geometry and stability of hydrated clusters LiB(OH)₄(H₂O)_n up to n = 8 were calculated at the B3LYP/aug-cc-pVDZ level. Three different types of ion association, namely, contact ion pairs (CIP), solvent-shared ion pairs (SIP) and solvent separated ion pairs (SSIP) were obtained; characteristics of all of these stable configurations were determined, and the most stable hydrated clusters were chosen. Then the mechanisms of ion aggregation and crystal nuclei formation in the LiB(OH)₄ solution were proposed. The tight four-hydrated sphere of Li⁺ makes it difficult for the dehydrated form of its first hydration sphere to from a CIP, which is the passible reason that lithium borate always has a large super-saturation degree.