疏水缔合水溶性聚合物的合成与表征

综述了疏水缔合型水溶性聚合物合成与表征方法，介绍了在合成过程中提高油溶性单体和水溶性单体混溶性的方法，简述了疏水物质含量的核磁共振、紫外光谱、裂解气相色谱等测定方法。     

Water‐soluble polymers. LXXXII. Shear degradation effects on drag reduction behavior of dilute polymer solutions

Drag reduction measurements were conducted on extensively characterized poly(ethylene oxide) and poly(acrylamide) utilizing a fully automated rotating disk rheometer equipped with an optical tachometer, torque transducer, and software allowing real‐time data acquisition. The instrument sensitivity allowed the study of concentrations as low as 0.1 ppm. In addition, previously immeasurable concentration‐ and time‐dependent shear degradation effects were readily observed. A power law equation was shown to adequately correlate the percentage of drag reduction and the volume fraction for each polymer. Furthermore, an empirical shift factor was utilized to superimpose data from all the systems that were studied. By conducting measurements in the proper concentration and time domains, it was possible to extract the minimal concentration for the maximum drag reduction efficiency in the absence of shear degradation. The resulting values were significantly higher than those previously reported by our laboratories for poly(ethylene oxide) and poly(acrylamide). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1211–1221, 2001     

Thermal and microwave‐assisted oxidative degradation of poly(ethylene oxide)

The kinetics of the thermal and microwave‐assisted oxidative degradation of poly(ethylene oxide) were determined with potassium persulfate as the oxidizing agent. Gel permeation chromatography was used to determine the variation of the molecular weight with time. The degradation was studied as a function of the temperature and persulfate concentration, and it was found that the degradation rate increased with the temperature and concentration of persulfate. Continuous distribution kinetics were used to determine the rate coefficients for the degradation process, and the activation energies were obtained. The results indicated that the microwave‐assisted process had a lower activation energy of 10.3 kcal/mol, whereas that of the thermal degradation was 25.2 kcal/mol. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2090–2096, 2005     

水溶性单体分散聚合的研究进展

综述了丙烯酰胺等六类水溶性单体分散聚合的研究现状。     

Thermal stability and degradation mechanism of C60 fullerene-based polymers

In this paper, the thermal stability and degradation mechanisms of C₆₀ fullerene-based polymers, obtained by click polymerization between dialkyne-substituted C₆₀ derivative monomers and 1,3,5-tris(dodecyloxy)benzene-based diazide comonomers, were evaluated. The activation energy of the fullerene polymer C₆₀P2 with an ethylene spacer, determined under peak degradation rate conditions, was lower than that of the counter polymer C₆₀P1 with a methylene spacer, suggesting lower thermal stability of C₆₀P2. The combined technique of thermogravimetric analysis—mass spectroscopy and Fourier transform infrared spectroscopy revealed that the thermal decomposition onset of the analyzed samples is accompanied by C C cleavage of the dodecyloxyside chain groups, followed by the decomposition of the 1,2,3-triazole, dicarboxylate and benzoate moieties. It was found that no thermal decomposition of the fullerene carbon cage occurs up to 670°C. Molecular modeling with Hyperchem software version 7.5 confirmed that C₆₀P1 is more thermally stable than C₆₀P2.     

Direct formation of emulsions using water‐soluble porous polymers as sacrificial scaffolds

BACKGROUND: Emulsions are traditionally formed from two immiscible liquids by mechanical stirring, homogenization, or ultrasonication. For the use of emulsions, stability during storage and transport has been an issue which needs to be addressed. Here, a novel method is proposed to form emulsions instantly by hand shaking from porous polymeric materials. RESULTS: The porous materials were prepared by a freeze‐drying method and then soaked in an oil phase. The oil was absorbed into the micron‐sized pores. The oil‐soaked composites were then placed in water. The dissolution of polymer led to the formation of emulsions by gentle hand shaking within 2 min. Mineral oil, soy oil with drug molecules, and perfluorodecalin were tested as the model oil phases. In each case, stable emulsions with high ratios of oil to water were formed instantly. CONCLUSIONS: A novel route is reported to produce emulsions instantly by hand shaking from porous polymeric materials. Using this method, emulsions could be formed instantly on the site just before application, thus avoiding the cost and stability concerns during transport and storage of emulsions. The method also has the advantages of easy operation and scale‐up possibility. Copyright © 2010 Society of Chemical Industry     

Synthesis of water‐soluble thermosensitive polymers having phosphonium groups from methacryloyloxyethyl trialkyl phosphonium chlorides–N‐isopropylacrylamide copolymers and their functions

Water‐soluble thermosensitive polymers having phosphonium groups were synthesized by the copolymerization of N‐isopropylacrylamide (NIPAAm) with methacryloyloxyethyl trialkyl phosphonium chlorides (METRs) having varying alkyl lengths. The relative viscosities of the copolymer solutions increased with increasing content of phosphonium groups in the copolymers and decreased with increasing chain length of alkyl chains in the phosphonium groups. However, the copolymers of METR with octyl groups in phosphonium groups (METO) and NIPAAm became water insoluble with increasing contents of METO moieties in the copolymers. The transmittance at 660 nm of the copolymer solutions above the lower critical solution temperature (LCST) decreased gradually with increasing temperature and decreased with increasing chain length of alkyl chains in the phosphonium groups. The transmittance at 660 nm of the copolymer solutions above the LCST was greatly affected by the addition of neutral salts such as KCl. The copolymers of METR with ethyl groups in phosphonium groups and NIPAAm and those of METR with butyl groups in phosphonium groups and NIPAAm had high flocculating abilities against bacterial suspensions. The METO–NIPAAm copolymer was found to have a high antibacterial activity. The flocculating ability and the antibacterial activity of the copolymers were affected by not only the content of phosphonium groups but also the alkyl chain length in the phosphonium groups in the copolymers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 386–393, 2003     

Water‐soluble polymers: Optimization of arsenate species retention by ultrafiltration

The liquid‐phase polymer‐based retention (LPR) technique was employed to study the retention of arsenate species by poly(vinylbenzyl trimethylammonium chloride), P(ClVBTA), and poly[2‐(acryloyloxy)ethyltrimethylammonium chloride], P(ClAETA). The effect of parameters such as polymer concentration, time exposure, competition of sulfate and phosphate anions, and the use of natural systems as drinking water on the retention of As(V) species was analyzed. The mole ratios of polymer : As(V) of (31 : 1), (20 : 1), (10 : 1), (6 : 1), and (3 : 1) by using the washing method at pH 8 and 6 were assayed. The retention capacity was a function of polymer concentration and pH. The optimum mole ratio of polymer : As(V) was (20 : 1) for all pHs studied and all polymeric structures. The polymer's activity recovery assays were performed by washing at pH 2 and 3. A 95% As(V) elimination was achieved from polymers. A study of competition in the presence of other anions was performed at the same polymer : As(V) ratio (20 : 1). At pH 8 and at the same concentration of arsenate anions, sulfate, and phosphate anions, no important competition on arsenic retention was observed. Assays for P(ClVBTA) at pH 8 and mole ratio of polymer : As(V) (20 : 1), (40 : 1), and (60 : 1) using drinking water showed that the efficiency was higher under these conditions for the three As(V) retention cases. An unbuffered system with drinking water was tested for washing and enrichment methods by determining the maximum saturation capacity of the P(ClVBTA) polymer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Phase equilibrium data on carbon dioxide hydrate in the presence of electrolytes,water soluble polymers and montmorillonite

Equilibrium formation conditions for carbon dioxide hydrate were measured in pure water and in aqueous polymer and electrolyte solutions. The solutions that were used include: polyethylene oxide, partially (10 and 90 percent) hydrolyzed polyacrylamide, sodium chloride and calcium chloride. Experiments with solutions containing both electrolyte and polymers were also performed. It was found that the electrolytes exhibited a substantial inhibiting effect whereas the polymers only slightly altered the equilibrium hydrate formation conditions. The measured equilibrium formation pressures were compared with the predictions from existing hydrate equilibria methods and were found to be in good agreement. The effect of montmorillonite was also studied and it was found that it did not affect the equilibrium hydrate formation conditions. A total of 101 experimental measurements are reported.     

Thermal degradation of poly(ethylene oxide) and polyacrylamide with ascorbic acid

The degradation of poly(ethylene oxide) and polyacrylamide in aqueous solution was studied with ascorbic acid. Gel permeation chromatograph was used to monitor molecular weight dynamics with time. A model based on continuous distribution kinetics showed that the experimental data matched well with theory. The results showed that the degradation of polymers is significantly enhanced in the presence of ascorbic acid. The degradation rate initially increased with ascorbic acid concentration but was independent of it at higher concentrations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3067–3072, 2006     

Thermal and photochemical degradation of PPO/HIPS blends

In general, polymer blends show a degradation behavior different from a simple combination of the individual components, making any forecast difficult without experiments. Interactions between polymers can sensibilize or stabilize the blend against degradation. In this work, the thermal and photooxidative degradation of blends of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) and high impact polystyrene (HIPS) have been studied under accelerated conditions. The extent of degradation was accompanied by infrared spectroscopy (FTIR) and Raman spectroscopy (FT‐Raman) and impact resistance and strain–stress testing followed its influence on the macroscopic properties of the blends. The results showed that HIPS and the blend containing 60 wt % of PPO are more susceptible to thermal and photochemical degradation, while the blends containing 40 and 50 wt % of PPO are more stable. Infrared and Raman spectroscopic analyses showed that the degradation of HIPS and its blends is caused not only by degradation of the polybutadiene phase. Effects of interactions, such as exchange of energy in excited state between the PPO and PS components of the polymeric matrix may also be responsible for the degradation and loss of mechanical properties of the PPO/HIPS blends. The chemical degradation directly affects the mechanical properties of the samples with photodegradation being more harmful than the thermal degradation at 75°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Convenient method for removing and concentrating hydrophobic organic compounds from water with amphiphilic polymers

A stable fluoroacrylate copolymer emulsion was successfully prepared by miniemulsion polymerization with fluoroacrylate, lauryl methylacrylate, and methyl methacrylate as monomers. Extremely hydrophobic fluoroacrylate, instead of conventional cosurfactants, was used as a reactive cosurfactant to stabilize the miniemulsions. The results indicated that fluoroacrylate retarded Ostwald ripening and allowed the production of stable miniemulsions. The chemical compositions of the copolymer were studied with Fourier transform infrared and ¹H‐NMR. The average composition of the copolymers prepared with miniemulsions was in good agreement with the feed ratio according to ¹H‐NMR from the integration ratios corresponding to typical protons of the individual monomers. The particle size distribution and morphology of the latex particles were determined with laser particle analysis and transmission electron microscopy. The particle size of the latex underwent no change in the process of miniemulsion polymerization, but the particle size distributions were broader than those of conventional emulsion polymerization. The effects of various reaction parameters, including the temperature and concentrations of the emulsifier and initiator, on the miniemulsion polymerization were also investigated, and the polymerization rate and conversion increased with increasing concentrations of nonylphenol polyethoxylate (with an average of 40 ethylene oxide units per molecule), cetyltrimethylammonium, and 2,2′‐azobisisobutyronitrile. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 641–647, 2007     

Intermolecular interactions between bovine serum albumin and certain water‐soluble polymers at various temperatures

Viscometric behaviors of dextran (Dx), poly(N‐vinyl‐2‐pyrrolidone) (PVP), and poly(ethylene oxide) (PEO) with bovine serum albumin (BSA) in aqueous solutions have been studied at 25, 30, and 35°C. The reduced viscosity and intrinsic viscosity have been experimentally measured for the polymer/water and polymer/BSA/water systems by classical Huggins equation. Measurements of reduced viscosities of the Dx, PVP, and PEO in water have been calculated and all intrinsic viscosities of PEO([η]_PEO) are larger than that of Dx([η]_Dx), and PVP([η]_PVP) in aqueous solutions, at all temperatures. The intrinsic viscosities of PVP, PEO, and Dx were found to be dependent on the concentration of BSA. The presence of BSA (0.05, 0.10, and 0.30 wt %) led to a decrease in the intrinsic viscosities of polymers, at 25, 30, and 35°C. The concentration difference of BSA (Δ[BSA]) is most effective in decreasing the intrinsic viscosities of Dx at 25°C and PEO at 30 and 35°C. In other words, Δ[η] (%) order followed as Dx > PEO > PVP at 25°C and PEO > Dx > PVP at 30 and 35°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1554–1560, 2006     

Low molecular weight water‐soluble chitosans: Preparation with the aid of cellulase,characterization, and solubility

Preparation of water‐soluble chitosan (WSC) was made by treating partially N‐deacetylated chitosan with acetic anhydride in aqueous acetic acid. The optimal conditions of preparing WSC were determined on the basis of orthogonal tests. Low molecular weight WSC with broad molecular weight (600–1.5 kDa) were obtained by the depolymerization of WSC using cellulase at optimum condition of pH 4.5 and 60°C. The solubility of WSC in water and aqueous organic solvents was investigated in detail. Weight–average molecular weight (M_w) and molecular weight distribution (M_w/M_n) of samples were measured by gel permeation chromatography. The structure of WSC and its degraded products were characterized by XRD, FTIR, and MALDI‐TOF MS. The decrease of molecular weight led to transformation of crystal structure and the increase of solubility, but the chemical structures of residues were not modified compared to WSC, which was not hydrolyzed. The solubility of the WSC in water and aqueous organic solvents increased with the decrease of molecular weight. The solubility of the WSC with low molecular weight was rather high even in aqueous dimethylacetamide and dimethylsulfoxide. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1098–1105, 2006     

Exactly alternating silarylene—siloxane polymers: 6. Thermal stability and degradation behaviour

The thermal stability and degradation behaviour of a series of twelve different exactly alternating silarylene—siloxane polymers were investigated by several different methods including thermal gravimetric analysis (t.g.a.) in air and in nitrogen, long term (up to 48 h) high temperature (600° and 900°C) isothermal degradation in nitrogen, and rapid pyrolysis in helium. No weight loss was observed by t.g.a. until about 400°C, and two distinctly different mechanisms were observed, one for degradation in nitrogen (a single step process), and the other in air (a three step process). Under nitrogen, black, insoluble, carbon-hydrogen-silicon containing degradation products were obtained, which were stable in pure oxygen to at least 1100°C. In air, pure SiO₂ was obtained after heating to above 730°C. Isothermal investigations revealed that at temperatures of 600°C and above, weight loss by thermal degradation under a nitrogen atmosphere was completed in less than an hour, and the polymeric products which remained thereafter did not change any further even after 48 h at 900°C.     

Synthesis and solution properties of water soluble copolymers based on acrylamide and quaternary ammonium acrylic comonomer

We have prepared cationic polyelectrolytes with a large range of compositions by the redox polymerization and copolymerization of acrylamide and (N,N,N-trimethyl) aminoethyl chloride acrylate. Molecular weights of the various samples were determined by light scattering, and the intrinsic viscosities of these polymers measured in aqueous solutions of various ionic strengths. We propose empirical laws between viscosity, composition in comonomers, molecular weight and ionic strength. Results also give the radius of gyration of macromolecules in NaCl solution (between 10^?2M and 1 M).     

Water‐soluble polymers. LXXXIII. Correlation of experimentally determined drag reduction efficiency and extensional viscosity of high molecular weight polymers in dilute aqueous solution

The extensional viscosity for aqueous solutions of high molecular weight poly(acrylamide) copolymers and poly(ethylene oxide) homopolymers was measured using a laboratory‐designed screen extensional rheometer. A Bingham model was developed to estimate the average local polymer coil extensional viscosity (η_coil). A strong correlation was found between the measured η_coil values and the polymer extensional viscosity predicted by a bead‐spring model. The dilute aqueous solution drag reduction was measured with a rotating disk instrument under conditions minimizing the effects of shear degradation. Extensional viscosity and drag reduction measurements were performed in deionized water and in 0.514M sodium chloride. The relative drag reduction efficiency values (Δ) in both solvents were found to strongly correlate with measured η_coil values. This is the first report of the accurate prediction of drag reduction behavior for a wide range of polymer types in various solvents from the independently measured molecular parameters η_coil and [η]C. The often‐used relative drag reduction efficiency expressed as the product of [η]C and Δ can now be replaced by the absolute drag reduction efficiency [η]Cη_coil. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1222–1231, 2001     

Water‐soluble cationic polymers and their polymer–metal complexes with biocidal activity: A genotoxicity study

Water‐soluble polyelectrolytes containing ammonium and sulfonic groups, their polymer–Ag(I) complexes, and silver nitrate were investigated as bactericidal compounds for Staphylococcus aureus (Collection No. ATCC 28922) and Escherichia coli (Collection No. 6538P) according to the National Committee for Clinical Laboratory Standards (NCCL) method. All the compounds, except Ag(I), showed bactericidal activity only for S. aureus. Ag(I) showed high bactericidal activity for both bacteria. No important effect of the molecular weight or macromolecular size on the maximum bactericidal concentration value was observed. The genotoxicity was studied using the rec assay. None of the macromolecular compounds showed genotoxicity, except silver ions, whose value was borderline. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 452–457, 2003     

Arsenite retention properties of water‐soluble metal–polymers

The properties of water‐soluble metal–polymers to retain As(III) from aqueous solution are investigated. Poly(acrylic acid)s with different tin contents are prepared. Amounts of 3, 5, 10, and 20 wt % of tin are added to the polymer. The metal compositions are evaluated by thermogravimetry (TG‐DSC) and atomic absorption spectroscopy. Structural properties are analyzed by infrared and ¹H nuclear magnetic resonance spectroscopy, and X‐ray diffraction. Additionally, specific surface area was measured using CO₂ as adsorbate. Arsenic retention properties are studied using the liquid‐phase polymer‐based retention (LPR) technique. The polymers can bind arsenic species from an aqueous solution in the pH range 4–8. The studies show that the retention capacity is a function of tin content and polymer concentration. At pH 8, the following mol ratios poly(AA)‐Sn : As(III) are analyzed: 600 : 1, 400 : 1, 200 : 1, 100 : 1, and 20 : 1. The highest retention, 80%, is obtained with poly(AA)‐Sn at 10 and 20 wt % of tin at mole ratios 400 : 1, and at nearly to 20 : 1 or 40 : 1 Sn‐As(III). The highest retention is observed at pH 8 and 4. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Functional water‐soluble polymers: polymer–metal ion removal and biocide properties

Water‐soluble polymers have attracted much interest due to their potential applications in environmental protection engineering to remove harmful pollutants and in biomedicine in the areas of tissue engineering, within‐body implants or other medical devices, artificial organ prostheses, ophthalmology, dentistry, bone repair, and so on. In this review, particular emphasis is given to the ability of water‐soluble polymers with amine, amide, carboxylic acid, hydroxyl and sulfonic acid functional groups to remove metal ions by means of the liquid‐phase polymer‐based retention (LPR) technique that combines the use of water‐soluble polymers and ultrafiltration membranes. The second part is dedicated to showing the potential application of functional water‐soluble polymers and their polymer–metal complexes as biocides for various bacteria. These polymers and polymer–metal complexes show an efficient bactericide activity, especially to Gram‐negative bacteria, Staphylococcus aureus reaching concentrations lower than 4 µg mL^?1. This activity depends on polymer size, type of metal ion, contact time and concentration of polymer and metal ion. The discussion reveals that in the case of the LPR process the efficiency of metal ion removal depends strongly on the type of polymer functional group and the feed pH value. In general, two mechanisms of ion entrapment are suggested: complex formation and electrostatic interaction. In the case of the medical use of water‐soluble polymers and their complexes with metal ions, the review documents the unique bactericide properties of the investigated species. The polymer‐metal ion complexes show a reduced genotoxic activity compared with free metal ions. Copyright © 2009 Society of Chemical Industry