bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deswelling stresses and reduced swelling of superabsorbent polymer in composites of fiber and superabsorbent polymers
Authors: Buchholz Fredric L. , Pesce Sandra R. , Powell Cynthia L. 
Published: September 2005

AbstractThe desired performance characteristics of absorbent products such as diapers include a low number of leaks, adequate liquid absorption capacity, and high skin dryness. By measuring the absorption behavior of mixtures of cellulose fluff pulp and superabsorbent polymers in nonimmersed conditions, we identify four major parameters that affect the swelling of the polymer in a composite: the Donnan ion‐exclusion effects of limiting the amount of liquid in contact with the superabsorbent polymer, the restriction of swelling by the physical constraints of the fibrous network that surrounds the polymer particles, the restriction of swelling by the capillary tension provided by the pores between the cellulose fibers, and the osmotic pressure of extracted polyelectrolytes. Swelling of the superabsorbent polymer in composites is always smaller than the value measured by immersion of the polymer followed by centrifugation. Donnan exclusion of ions from the gel phase results in about 16% less swelling than when the polymers are swollen in excess liquid. The swelling restriction imposed by the fiber network, which surrounds the granules, reduces swelling a further 10%. In addition, the presence of small pores between the fibers exerts capillary tension on the polymer and lowers the swelling by another 10%. The external compression of the composite pads does not reduce the extent of swelling of the superabsorbent polymer because the stress is supported by the fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2493–2507, 2005
Preparation and evaluation of a dispersant for gypsum paste from acid hydrolysis lignin
Authors: Matsushita Yasuyuki , Imai Masanori , Tamura Takashi , Fukushima Kazuhiko 
Published: September 2005

AbstractThe preparation of dispersants with carboxyl groups from acid lignin (a byproduct in the saccharification process of woody materials that are renewable resources) was investigated, and their dispersion efficiency was evaluated. In this study, sulfuric acid lignin (SAL) was selected as a representative acid lignin. To convert SAL to water‐soluble polymers, it was first subjected to phenolation with sulfuric acid to enhance its chemical reactivity. The introduction of a carboxy group was carried out with two methods. One was carboxymethylation with bromoacetic acid, and the other was the Mannich reaction with glycine, sarcosine, and iminodiacetic acid. The carboxymethylation product [carboxymethylated phenolized sulfuric acid lignin (CP‐SAL)] with 1.4 carboxymethyl groups per phenolated phenylpropane lignin base unit was soluble in water. The Mannich reaction products were also soluble in water with a lower addition of carboxyl groups than that for CP‐SAL. Surprisingly, all the prepared water‐soluble polymers possessed a higher dispersibility for gypsum paste than commercial lignosulfate. This may be due to the higher molecular weights of acid lignin derivatives. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2508–2513, 2005
Effect of ionic content, solid content, degree of neutralization, and chain extension on aqueous polyurethane dispersions prepared by prepolymer method
Authors: Nanda Ajaya K. , Wicks Douglas A. , Madbouly Samy A. , Otaigbe Joshua U. 
Published: September 2005

AbstractThere are many variables in the preparation of aqueous polyurethane (PU) dispersions. Carboxylic acid content, solid content, degree of pre/postneutralization of the carboxylic acids, and chain extension all impact dispersion particle size, viscosity, pH, molecular weights, and glass transition temperature. This study evaluated the impact of these variables on a given PU dispersion formulation prepared from isophorone diisocyanate, an aliphatic polyester polyol, dimethylol propionic acid, and hexamethylene diamine with triethyl amine as the neutralizing base and N‐methyl pyrrolidone as the cosolvent. Changes in carboxylic acid content, degree of preneutralization, and chain extension were found to have the expected impacts on dispersions properties. Increased ionic content in the dispersion step led to lower particle size and higher viscosity, increased chain extension with its concurrent increase in molecular improved subsequent film properties. Surprising results were obtained by varying the amount of postneutralization and from increased solids content at the time of dispersion. Unexpectedly, both of these variations led to much higher dispersion viscosities and particle size in solution. To have these changes take place, it is theorized that there is a major change in solution morphology caused by these modifications. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2514–2520, 2005
Thermodynamic interactions of a copolyester of bisphenol A with terephthalic acid and isophthalic acid with some solvents
Authors: Sakar Dolunay , Cankurtaran Ozlem , Karaman Ferdane Yilmaz 
Published: September 2005

AbstractThe retention diagrams of n‐octane, n‐nonane, n‐decane, n‐butyl acetate, isobutyl acetate, and isoamyl acetate on the polyarylate Ardel D‐100, a copolyester of bisphenol A with terephthalic acid and isophthalic acid, were plotted at temperatures between 120 and 260°C by an inverse gas chromatography technique. The glass‐transition temperature of the copolymer was determined to be 190°C from the discontinuity of these diagrams. The retention diagrams of benzene, ethyl benzene, n‐propyl benzene, isopropyl benzene, and chlorobenzene were also plotted between 200 and 260°C. The specific retention volume, weight fraction activity coefficient, Flory–Huggins polymer–solvent interaction parameter, hard‐core polymer–solvent interaction parameter, and effective exchange energy parameter were determined for the studied solvents. The parameters suggest that the studied aromatic hydrocarbons and aliphatic esters are moderately good solvents and chlorobenzene is a very good solvent for this copolyester, but the n‐alkanes are very poor solvents. The solubility parameter of this copolymer was determined to be 11.6 (cal/cm3)1/2 at room temperature by extrapolation of the values of the solubility parameters from the studied temperatures to 25°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2365–2368, 2005
Properties and application of novel amphoteric polypropylene fabrics
Authors: Mosleh S. , Gawish S. M. , Khalil F. H. , Bieniek R. F. 
Published: September 2005

AbstractThe properties and characterization of a novel series of amphoteric polypropylene fabrics were done by γ‐preirradiation followed by grafting methacrylic acid and then amination using (3‐chloro‐2‐hydroxyl propyl)ammonium derivatives. The new amphoteric grafted PP fabrics have an increase in moisture regain up to 5.5% and100% reduction in growth of Staphylococcus aureus and Klebsiella pneumonia. Also, the dyeability was improved using acid and basic dyes. These new amphoteric textiles properties were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis including TGA and DTA. A slight decrease in the crystallinity was observed by DSC and X‐ray diffraction. The modified PP fabrics can be used for the development of upholstery and medical fabrics with antimicrobial properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2373–2379, 2005
Water absorption in epoxy resins: The effects of the crosslinking agent and curing temperature
Authors: Abdelkader A. F. , White J. R. 
Published: September 2005

AbstractEpoxy systems were prepared with the same epoxide (diglycidyl ether of bisphenol A) with five different hardeners: 4,4′‐diaminodiphenylmethane (H1), diethylenetriamine (H2), a cycloaliphatic amine based on isophorone diamine (H3), a polyaminoimidazoline‐based hardener (H4), and a polyamidoamine‐based adduct hardener (H5). Samples were subjected to four different postcure treatment temperatures (23, 55, 75, and 150°C). Water absorption kinetics were obtained for each material and for each postcure treatment. The water absorption behaviors for the materials with H1, H2, and H3 were similar, whereas those for H4 and H5 were quite different. This is discussed in terms of the molecular structures of the hardeners. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2544–2549, 2005
New polymer synthesis. XXX. Synthesis and thermal behavior of new organometallic polyketones and copolyketones based on diferrocenylidenecycloheptanone
Authors: Aly Kamal I. , Abdel Monem Maisa I. 
Published: September 2005

AbstractA new interesting category of organometallic polyketones and copolyketones was synthesized via Friedel–Crafts reactions through the polymerization of 2,7‐bis[(2‐ferrocenyl)methylene] cycloheptanone (II) with different diacid chlorides. The model compound was synthesized by reacting monomer II with benzoyl chloride and characterized by 1H‐NMR, IR, and elemental analyses. The polyketones and copolyketones were insoluble in most organic solvents but easily soluble in concentrated H2SO4. The thermal properties of these polyketones and copolyketones were evaluated and correlated to their structural units by TGA and DTG measurements and had inherent viscosity of 0.32–0.65 dI g−1. Moreover, the electrical conductivity of polyketone Va and copolyketone VI was investigated above the temperature range (300–500 K) and followed an Arrhenius equation with activation energy 2.09 eV. Also, the morphological properties of selected example of polyketones were detected by scanning electron microscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2394–2401, 2005
Synthesis and characterization of magnetorheological polyimide gels
Authors: Fuchs A. , Hu B. , Gordaninejad F. , Evrensel C 
Published: September 2005

AbstractMagnetorheological polymer gels (MRPGs) are composite fluids containing ferrous particles suspended in a polymer gel. In addition to modification of the carrier fluid, the polymer gel, which includes crosslinked copolyimide (CCPI) and solvent N‐octylpyrrolidone, also changes the surface properties of the ferrous particles, thus reducing the particle settling and improving particle redispersion. The viscosity of MRPGs can be easily adjusted by controlling the concentration of CCPI in the carrier medium. High thermally resistant CCPI is synthesized from dianhydride, diamine, diaminobenzonic acid, and crosslinker and has a high glass transition temperature because the crosslinking ratio can be controlled by the molar ratio of diamine to diaminobenzonic acid. The redispersion and rheological properties are also investigated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2402–2413, 2005
Effect of PEG additives on properties and morphologies of membranes prepared from poly(2,6‐dimethyl‐1,4‐phenylene oxide) by benzyl bromination and in situ amination
Authors: Tang Beibei , Wu Dan , Xu Tongwen 
Published: September 2005

AbstractThis study investigated the effect of PEG additive on the structure formation and permeation properties of membranes. The membranes were prepared from a bromomethylated poly(2,6‐dimethyl‐1,4‐phenylene oxide)/chlorobenzene/ethanol system using the phase inversion method with PEG as an additive. As expected, PEG with a fixed molecular weight (e.g., PEG 600) acted as a pore‐forming agent, and membrane porosity increased as the PEG content of the casting solution increased. However, when the PEG content was fixed, the effect of PEG on the membrane properties and morphology was largely dependent on its molecular weight. It was found that when the molecular weight of PEG was less than 800, it acted as a pore former, but when the molecular weight of PEG was more than 1000, the pore size and porosity of the resulting membrane decreased. These results can be explained by the membrane‐forming system's thermodynamic and kinetic properties, which can be assessed by coagulation value and viscosity. Furthermore, the membranes were characterized for pure water flux and rejection of solute and by SEM observation. The filtration results agreed well with the SEM observations. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2414–2421, 2005
Interaction of microcrystalline chitosan with Ni(II) and Mn(II) ions in aqueous solution
Authors: Bodek Kazimiera Henryka , Kufelnicki Aleksander 
Published: September 2005

AbstractThe protonation constant of the NH2 function was determined by the method of Katchalsky and Spitnik and by the SUPERQUAD fitting procedure. Samples with higher concentrations of chitosan indicated aggregations of polymer chains, which led to a loss in the effective concentration of the ligand (L). It followed, as a result of potentiometric titrations, that an excess of L of microcrystalline chitosan (MCCh) with a deacetylation degree of 0.90 was a complexing agent toward the metal (M), which was Ni(II) or Mn(II). Species ML and ML2 were accepted by SUPERQUAD for both of the M's, where coordination occurred via the amino nitrogen. For Ni(II), however, the hydroxyl oxygen may also have been an electron‐pair donor at lower excesses of MCCh and, by that, made possible the formation of five‐membered chelate rings in the hydroxyl deprotonated MLH‐1 species. The evaluated formation constants were compared with the values known until now for monomeric D‐glucosamine. Additional confirmation of the M–L interaction was determined by the spectrophotometric titration of a Ni(II)–MCCh solution. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2572–2577, 2005
Dissolution of condensed tannin with phenol: Optimum reaction parameters and some flow properties
Authors: Samil A. , Alma M. H. , Acemioğlu B. 
Published: September 2005

AbstractCondensed tannins from the bark of black wattle (Acacia mearnsii L.) were solubilized with phenol using HCl as a catalyst. The optimum reaction parameters (temperature, time, and acid concentration) of the dissolution were determined. The results showed a clear effect on the percentage of reacted phenol and residue tannin by temperature, time and, particularly, acid concentration. It was found that almost 77% of the phenol used could be reacted with the tannin, and about 90% of the tannin could be solubilized into phenol in the presence of HCl (as a catalyst) having a concentration of 5%. The optimum temperature, time, and acid concentration were 160°C, 90 min, and 4%–5%, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2450–2453, 2005
The dynamic mechanical properties of EPDM/Al(OH)3 composites
Authors: Gao Naikui , Li Jianying , Li Shengtao , Peng Zongren 
Published: September 2005

AbstractThe effects of volume fraction, particle size, and surface state of Al(OH)3 fillers on the dynamic mechanical properties of EPDM/Al(OH)3 composites were investigated by dynamic mechanical analysis (DMA). The interfacial structure parameters of EPDM/Al(OH)3 composites were also investigated. The results show that dynamic mechanical property and the glass‐transition process of composites are distinctly influenced by the volume fraction, particle size, and surface state of Al(OH)3 fillers. With the increase of volume fraction and decrease of particle size of Al(OH)3 fillers, the temperature corresponding to the maximum damping factor of composites shifts to a higher temperature with lower peak value and broader half‐peak width. The treatment of fillers with coupling agent can greatly enhance two‐phase interaction and thus improve the dynamic mechanical properties of composites. Consequently, a lower damping factor, broader half‐peak width, and larger apparent activation energy of glass transition can be achieved. In addition, a novel method of calculating the apparent activation energy of composites is put forward based on the DMA method, which has been verified by calculating the apparent activation energy of glass transition of Al(OH)3‐filled EPDM composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2454–2460, 2005
A novel microsurgery method for intact plant tissue at the single cell level using ArF excimer laser microprojection
Authors: Kajiyama Shin'ichiro , Shoji Takeshi , Okuda Shinya , Izumi Yoshihiro , Fukusaki Ei‐ichiro , Kobayashi Akio 
Published: September 2005

AbstractA novel microsurgery technique for the partial removal of rigid cell‐walls in intact plant tissue is established. Using a size‐variable slit, an ArF excimer laser was microprojected on the surface of the targeted cell, and this method enabled the area‐ and depth‐controllable processing of the cortical structure of plant cells including the cuticle and cell wall layer. In epidermal cells of all tested plants, viabilities of more than 90% were retained 24 h after irradiation. Scanning electron microscope (SEM) observation revealed that the cuticle layer of the irradiated region was completely ablated, and the cellulose microfibrils of the secondary cell wall were partially removed; furthermore, 4 days after laser treatment, the regeneration of cell wall fibrils was observed. As a model experiment, the transient expression of synthetic green fluorescent protein (sGFP) was performed by the microinjection of cauliflower mosaic virus (CMV) 35S promoter‐derived sGFP gene through an “aperture” in the treated cell surface. Moreover, micron‐sized fluorescent beads were successfully introduced by the same method into the onion cells indicating that this method can be used to introduce foreign materials as large as organelles. © 2005 Wiley Periodicals, Inc.
Characteristics of protein partitioning in an aqueous micellar‐gel system
Authors: van den Broeke L.J.P. , van Roosmalen D. , Dohmen‐Speelmans M.P.J. , Dietz C.H.J.T. , van der Wielen L.A.M. , Keurentjes J.T.F. 
Published: September 2005

AbstractPartitioning of proteins has been studied experimentally in a system combining a gel‐bead phase and a nonionic micellar phase. The micellar phase consists of cylindrically shaped micelles, which are completely excluded from the gel‐bead phase. Partitioning of single‐component protein solutions (myoglobin, ovalbumin, and BSA) is determined by excluded‐volume interactions in the micellar phase, and as a result the proteins prefer the gel‐bead phase to the micellar phase. The protein concentration inside the gel beads increases with an increase in volume fraction of the micelles and increases with an increase in the size of the proteins. The protein partition coefficients obtained for a binary mixture of myoglobin and bovine serum albumin (BSA) show the same protein concentration dependence as the single‐component protein partition coefficients. © 2005 Wiley Periodicals, Inc.
Phytol‐modified heme in mesoporous silica: Conjugates as models of hemoproteins
Authors: Itoh Tetsuji , Yano Kazuhisa , Kajino Tsutomu , Inada Yuji , Fukushima Yoshiaki 
Published: September 2005

AbstractA ferriprotoporphyrin, hemin (Fe3+), modified with 3,7,11,15‐tetramethyl‐2‐hexadecen‐1‐ol, phytol, was adsorbed in nano‐spaces of about 4 nm in diameter in mesoporous silica (FSM; folded‐sheet mesoporous material) forming a phytol‐modified hemin (Fe3+)–FSM nano‐conjugate. The properties and the structure of the conjugate were studied by UV‐visible light absorption, IR absorption spectroscopy, and a nitrogen adsorption isotherm. Although the hemin without phytol could not be adsorbed to the mesoporous silica, modification with phytol imparted preferential adsorption properties. The conjugate was not only stable but also had a peroxidase‐like activity in a 0.1% hydrogen peroxide solution, while free hemin in the solution was easily destroyed. The hemin (Fe3+) in the FSM was reduced to heme (Fe2+) by hydrazine. The phytol‐modified heme (Fe2+)–FSM conjugate formed an O2–heme complex with a superoxide type structure, resembling oxyhemoglobin or oxymyoglobin, which has not been previously observed for free heme in solution. The addition of carbon monoxide or nitrogen monoxide to the phytol‐modified heme (Fe2+)–FSM conjugate caused the formation of CO– or NO–heme complex in the nano‐spaces of the FSM. These properties are attributed not only to the Fe‐complex but also to the cooperative functions of the heme with mesoporous silica, resembling properties of a natural heme–protein conjugate; hemoglobin or peroxidase. These results are an elegant example of biomimetic nano‐technology. © 2005 Wiley Periodicals, Inc.
Regions of Tau Implicated in the Paired Helical Fragment Core as Defined by NMR
Authors: Sillen Alain , Leroy Arnaud , Wieruszeski Jean‐Michel , Loyens Anne , Beauvillain Jean‐Claude , Buée Luc , Landrieu Isabelle , Lippens Guy 
Published: September 2005

AbstractWe have studied the mature Alzheimer‐like fibers of tau by fluorescence and NMR spectroscopy. Assembly of the protein into paired helical filaments after incubation with heparin at 37 °C was verified by electron microscopy and size‐exclusion chromatography. NMR spectroscopy on these mature fibers revealed different regions of residual mobility for tau: the N‐terminal domain was found to maintain solution‐like dynamics and was followed by a large domain of decreasing mobility; finally the core region was distinguished by a solid‐like character. Heteronuclear‐NOE data indicate that the decreasing mobility is due to both a slowing down of the rapid nanosecond movements and the introduction of slower movements that lead to exchange broadening. Fluorescence spectroscopy confirmed the presence of this rigid core, and some degree of protection from hydrogen exchange for those residues was observed. Hence, our data give a more precise picture of the dynamics of tau when it is integrated into mature filaments and should provide further understanding of the molecular processes that govern aggregation.
Site‐Selective DNA Hydrolysis by CeIV–EDTA with the Use of One Oligonucleotide Additive Bearing Two Monophosphates
Authors: Chen Wen , Komiyama Makoto 
Published: September 2005

AbstractTwo deoxyuridine derivatives each bearing a monophosphate group at the 5‐position with a C3 linker, were incorporated into an oligonucleotide. By using this modified oligonucleotide, a bulge was formed at a predetermined position in a DNA substrate, and two monophosphate groups were placed at both junctions of the bulge. Upon treatment of the mixture with CeIV–EDTA at pH 7.0, the phosphodiester linkages at the bulge site were selectively and efficiently hydrolyzed. The monophosphate groups introduced into the bulge site greatly accelerated site‐selective DNA scission. Compared with the previously reported two‐additive system, which combines two oligonucleotide additives each with a monophosphate at their termini, the present one‐additive system is simpler and more convenient. Furthermore, site‐selective DNA hydrolysis by using this one‐additive system is successful even at high reaction temperatures (e.g., 55 °C). This reflects the thermodynamic stability of the duplexes formed between the substrate and the additive DNA.