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The surface of carbonyl iron powder (CIP) was modified in supercritical fluid with silicone polymers containing reactive Si-OCH3 groups. Fourier-transformed infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and thermo gravimetric analysis were adopted to characterize CIP. The dispersibility of CIP in epoxy resin matrix was evaluated by castor oil absorption factor, dynamic viscosity, Mooney viscosity, and scanning electric micrograph. The electromagnetic reflectivity of the CIP-filled epoxy resin coatings was also checked. It was confirmed that comparing with those treated at atmosphere, the supercritical treated CIP presented higher surface carbon content, higher dispersibility, higher thermal stability, and its original crystalline structure did not change greatly. Even though it experienced a high temperature and a high pressure (250 °C, 7.8 Mpa) during supercritical treatment, it was not oxidized, and its electromagnetic reflectivity did not decrease. Copyright © 2016 John Wiley & Sons, Ltd.

The terpolymer (PASA) of acrylamide with butyl styrene and sodium 2-acrylamido-2-methylpropane sulfonate was synthesized. The composition and molecular structure were characterized by elemental analysis, UV, FTIR, and 1H NMR. The aggregation behaviors of PASA were studied by means of the fluorescent probe analysis and environmental scanning electron microscope (ESEM). The flourescent probe analysis indicates that the PASA molecules form excellent hydrophobically associating structures in pure water and with the increase in PASA concentration at low concentrations, the nonpolarity of hydrophobic microdomains and the degree of intermolecular hydrophobic association increase in aqueous and brine solution. ESEM measurements show that gigantic aggregates have been formed in the PASA aqueous solution at the polymer concentration of 0.05 g dL−1, which is the critical association concentration of the polymer, and excellent solution properties of PASA are attributed to integrated network-structures formed by PASA in aqueous solution, which are collapsed by the addition of salt, resulting in the decrease in apparent viscosity of PASA in brine solution. However, with the increase in the NaCl concentration or the PASA concentration, the number and size of aggregates increase, leading to the remarkable increase in the apparent viscosity of PASA in brine solution. These results are consistent with the AFM and viscosity study results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:277–286, 2007

The synthesized hydrophobically associating water-soluble polymer P(AM-BST-NaAMPS) (PASA) exhibits good viscosification properties in the aqueous and brine solution. To study the viscosifying mechanisms of the polymer in the aqueous solution and brine solution, atomic force microscope (AFM) was applied to observe the micromorphology of the polymer solution. The AFM measurements show that continuous network structures have been formed in the aqueous solution of 0.05 g dL−1 PASA, and with the increase in PASA concentration, the network structures become much bigger and more condensed. The network structures of PASA are collapsed by the addition of salt, and tree-like crystals are formed, leading to the decrease in the apparent viscosity of PASA solution. However, by increasing the NaCl concentration or the polymer concentration in the brine solution, the sizes of crystals increase. These results are consistent with the ESEM and viscosity study results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3996–4002, 2006

The terpolymers (PASA) with acrylamide (AM), butyl styrene (BST), and sodium 2-acrylamido-2-methylpropane sulfonate (NaAMPS) were synthesized by the micellar free radical copolymerization technique. The polymer composition was determined by the elemental analysis, and the block structure of PASA was characterized directly by DSC measurement. Incorporation of NaAMPS into the terpolymers may improve the water solubility and intermolecular association, and the feed amount of BST, sodium dodecyl sulfate (SDS) amount, and the total monomer concentration in the polymerization can influence apparently the viscosities of PASA. The polymer exhibits excellent viscosification effect, salt-thickening, temperature-thickening, thixotropy, pseudoplastic behavior or shear-thickening relative to the BST content in PASA, excellent antiaging property at 85°C, and a dramatic increase in solution viscosity by the addition of little amount of SDS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4027–4038, 2007

Hydrophobically modified hydroxyethyl cellulose (BD-HAHEC) was synthesized by the macromolecular reaction of hydroxyethyl cellulose (HEC) with bromododecane (BD). Study of the effects of polymer concentration, shear rate, temperature, and electrolytes on the rheological behavior of BD-HAHEC indicated that the polymers had high viscosity, excellent viscosity retention in brine water, good thermal stability, and surface activity. Furthermore, investigation of the micromorphology of BD-HAHEC solutions revealed the close relationship of rheological behavior and a hydrophobically associating effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3346–3352, 2006

Through the macromolecule reaction method, the hydrophobically modified hydroxyethyl cellulose (EP16–HAHEC) was synthesized using 1, 2-epoxyhexadecane as the hydrophobic monomer. The solution properties of EP16–HAHEC were comprehensively investigated, which showed that the polymer with enhanced; viscosification property, thermal stability, shear resistance, and salt resistance was obtained. Amphiphilic structure of EP16–HAHEC molecules contributed to the surface activity of the polymer. By forming complex solution with surfactants or carboxylmethyl cellulose (CMC), the viscosification property of EP16–HAHEC could be enhanced through the interactions of hydrophobic groups and hydrogen bonds. The viscosity-enhancing mechanism of HAHEC was studied by the environment scan electronic microscope (ESEM) and the fluorescence spectrum measurements, which demonstrated that the formation of the supramolecular aggregation networks was coincident with the increase of the apparent viscosity of HAHEC. With the gradual formation of the complete polymer molecule networks, the apparent viscosity rised dramatically, and the associating aggregations of the polymer molecules appeared far before the great change of the macroproperty of the polymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2953–2959, 2006

Through the macromolecule reaction method, a series of 4-isopropylbenzyl chloride (IPBC) hydrophobically-modified hydroxyethyl cellulose (HAHEC) were synthesized. The use of suitable amount of hydrophobic monomer can ensure both the strong intermolecular association and good water-solubility of HAHEC. Effects of polymer concentration, shear rates, temperature, and electrolytes on the solution behavior of HAHEC were comprehensively studied, which indicated that the polymers show high viscosification property, excellent viscosity retention in brine water, and surface activity. FTIR, DSC, and UV measurements were applied to characterize the molecular structure and composition of HAHEC to confirm the incorporation of hydrophobic group into the polymer chain. Atomic force microscope (AFM) and fluorescence spectrum measurements were applied to study the formation of the molecule aggregation and hydrophobic microdomain of HAHEC, and revealed the close relationship between the rheological behaviors and the hydrophobic viscosification effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2824–2831, 2006

Alginate and gelatin blend fibers were prepared by spinning their solution through a viscose-type spinneret into a coagulating bath containing aqueous CaCl2 and ethanol. The structure and properties of the blend fibers were studied with the aid of infrared spectra, scanning electron micrography, X-ray diffraction, and thermogravimetric analysis. Mechanical properties and water-retention properties were measured. The best values of the tensile strength and breaking elongation of blend fibers were obtained when gelatin content was 30 wt %. The water-retention values of blend fibers increase as the amount of gelatin is raised. The structural analysis indicated that there was strong interaction and good miscibility between alginate and gelatin molecules resulted from intermolecular hydrogen bonds. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1625–1629, 2005

Copolymers of acrylamide, 2-acrylamide-2-methylpropanesulfate (AMPS), and hydrophobic monomer N-arylalkylacrylamide (BAAM) were synthesized by free-radical micellar copolymerization. The effects of the copolymer, BAAM, AMPS, and NaCl concentrations and the pH value on the apparent viscosity of the copolymers were studied. The solution viscosities increased sharply when the copolymer concentration was higher than the critical associating concentration. The apparent viscosities of aqueous solutions of poly(N-arylalkylacrylamide-co-acrylamide-co-2-acrylamide-2-methylpropanesulfate) (PBAMS) increased with increasing BAAM and AMPS concentrations. PBAMS exhibited good salt resistance. With increasing pH, the apparent viscosities first increased and then decreased. Dilute PBAMS solutions exhibited Newtonian behavior, whereas semidilute aqueous and salt solutions exhibited shear-thickening behavior at a lower shear rate and pseudoplastic behavior at a higher rate. Upon the removal of shear, the aqueous solution viscosities recovered and became even greater than the original viscosity, but the salt solution viscosities could not recover instantaneously. The elastic properties of PBAMS solutions were more dominant than the viscous properties, and this suggested a significant buildup of a network structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 316–321, 2005

This work focuses on the AFM study of the aggregation morphology and association mechanism of the hydrophobically-association water-soluble polymer P (AM-AA-BPAM) in aqueous solution. It shows that the P (AM-AA-BPAM) molecule chain, which has hydrophobic and hydrophilic ionic groups, forms the “spherical” aggregations as micelles below 0.2 g · dL−1, and then connect each other to form the string-like aggregations, which produce large viscosity for the polymer solution. It is also coincident with the FCS, DLS, and viscosity study result. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1175–1178, 2004

The interactions of hydrophobically modified polyelectrolytes poly(acrylamide–sodium acrylic acid–N-(4-butyl)phenylacrylamide [P(AM-AA-BPAM)] with anionic (sodium dodecyl sulfate), cationic (cetyl trimethylammonium bromide), and nonionic (tetradecyldimethyl-aminoxid) surfactants were studied via solution rheology, surface tension, and atomic force microscopy measurements. Viscosity measurements indicated that the intermolecular association of the polymer was greatly enhanced by the interaction with the surfactants, especially the oppositely charged surfactants with both a hydrophobic association and an electrostatic attraction. The greatest viscosity increase was realized with the addition of such oppositely charged surfactants. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2664–2671, 2003

Chitosan and poly(vinyl alcohol) blend fibers were prepared by spinning their solution through a viscose-type spinneret at 25°C into a coagulating bath containing aqueous NaOH and ethanol. The influence of coagulation solution composition on the spinning performance was discussed, and the intermolecular interactions of blend fibers were studied by infrared analysis (IR), X-ray diffraction (XRD), and scanning electron micrograph (SEM) and by measurements of mechanical properties and water-retention properties. The results demonstrated that the water-retention properties and mechanical properties of the blend fibers increase due to the presence of PVA in the chitosan substract, and the mechanical strength of the blends is also related to PVA content and the degree of deacetylation of chitosan. The best mechanical strength values of the blend fibers, 1.82 cN/d (dry state) and 0.81 cN/d (wet state), were obtained when PVA content was 20 wt % and the degree of deacetylation of chitosan was 90.2%. The strength of the blend fibers, especially wet tenacity could be improved further by crosslinking with glutaraldehyde. The water-retention values (WRV) of the blend fibers were between 170 and 241%, obviously higher than pure chitosan fiber (120%). The structure analysis indicated that there are strong interaction and good miscibility between chitosan and poly(vinyl alcohol) molecular resulted from intermolecular hydrogen bonds. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2558–2565, 2001

A new kind of hydrophobically associating water-soluble terpolymer P(AM-NVP-DMDA) was synthesized by free radical terpolymerization. Compared with micellar terpolymerization, this terpolymerization can be conducted in aqueous solution in absence of external surfactant, because the hydrophobic monomer is surface active. Synthesis, structure, and solution properties of P(AM-NVP-DMDA) terpolymer were studied, including its electrolyte effect, rheological behavior, temperature dependence of viscosity, dilute solution property, and the polymer-alkali, polymer-surfactant interaction. The terpolymer shows strong hydrophobic effect, and the terpolymer aqueous brine solution exhibits high viscosity at low polymer concentration. Incorporation of N-vinyl-pyrrolidone into the terpolymer causes an improvement in thermal stability of the terpolymer. The transmission electron photomicrograph analysis of the terpolymer indicates that the presence of the microphase separation of the terpolymer in aqueous solution plays an important role in the viscosification efficiency of the terpolymer.