bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and properties of novel flame‐retardant poly(amide‐imide)s containing phosphine oxide moieties in main chain by microwave irradiation
Authors: Faghihi Khalil , Zamani Khosrow
Published: June 2006

Eight new flame‐retardant poly(amide‐imide)s with high inherent viscosities containing phosphine oxide moieties in main chain were synthesized from the polycondensation reaction of N,N′‐(3,3′‐diphenylphenylphosphine oxide) bistrimellitimide diacid chloride 7, with eight ;aromatic diamine 8a–h by two different methods such as solution and microwave‐assisted polycondensation. Results showed that the microwave‐assisted polycondensation by using a domestic microwave oven proceeded rapidly, compared with solution polycondensation and were completed within about 10–12 min. The resulting poly(amide‐imide)s 9a–h showed high thermal stability and flame‐retardant properties. All of the obtained polymers were fully characterized by means of elemental analysis, viscosity measurements, solubility test, and FTIR spectroscopy. Thermal properties of the PAIs 9a–h were investigated by using thermal gravimetric analysis (TGA), derivative thermogravimetric analysis (DTG), and differential scanning calorimetry (DSC). Char yield measurements at 600°C demonstrated that incorporating phosphine oxide moieties in polymer backbone markedly improves their flame retardancy. All of the earlier polymers were soluble at room temperature in various organic solvents such as NMP, DMF, DMSO, DMAc, and concentrated sulfuric acid. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4263–4269, 2006
Waste‐reducing preparation of PE‐g‐MAH and PE‐g‐DBM via solid phase grafting reaction and their application as compatibilizers
Authors: Song Yujun , Liu Changgeng
Published: June 2006

Kinetics for grafting two reactive monomers (dibutyl maleate (DBM) and maleic anhydride (MAH)) on polyethylene (PE) was investigated for the modified PE (PE‐g‐MAH and PE‐g‐DBM) using solid phase grafting process. This process avoided solvent waste produced in solution process and high operation temperature in melt process. In the presence of the radical initiator, coupling reactions, between the PE and product, and macromolecular radicals, routinely form gels and/or increase molecular weight, resulting in a worse rheological behavior for the grafting products. By adding small amount of interface agents, using combined initiators and optimizing reactor design, graft copolymers with controlled grafting degrees and good rheological properties were prepared. The grafting degrees of copolymers were determined by chemical analysis. FTIR, DSC, and pure water contact angle characterized the chemical structure, the thermal property, and the hydrophilic property of the grafting copolymers, respectively. The peel strength of the graft copolymer as powder coating on the stainless steel surface was measured as high as 12–24 kgf/cm. Mechanical strength and toughness of PE/kaolin clay, PVC/CPE, and PVC/CPE/CaCO3 alloys with small amount of the graft copolymer (∼5 wt %) added were improved significantly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3781–3790, 2006
Two‐dimensional regular nanopatterning on block copolymer substrate having lamellar morphology using star‐hyperbranched nanospheres by electrostatic interaction
Authors: Ishizu Koji , Ochi Koichiro , Uchida Satoshi , Odoi Keisuke
Published: June 2006

Hyperbranched polystyrenes (PS) were prepared by living radical photopolymerization of 4‐vinylbenzyl N,N‐diethyldithiocarbamate as an inimer under UV irradiation. The star‐hyperbranched copolymers were derived by grafting from surface N,N‐diethyldithiocarbamate groups of hyperbranched macroinitiator with t‐butyl methacrylate in the presence of N,N‐tetraethylthiuram disulfide. We obtained poly(methacrylic acid) star‐hyperbranched PS nanospheres by hydrolysis of poly(t‐butyl methacrylate)‐grafted chains. We established two‐dimensional (2D) regular nanopatterning by aligning continuously such nanospheres on poly(2‐vinylpyridine) (P2VP) lamellar layers of PS‐block‐P2VP diblock copolymer film. Electrostatic interaction between nanosphere surface having negative charges (COOCs) and P2VP lamellar layer acted effectively for the 2D nanopattern formation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4206–4210, 2006
Artificial neural network modeling for predicting melt‐blowing processing
Authors: Chen Ting , Wang Jun , Huang Xiubao
Published: June 2006

An artificial neural network (ANN) model is established for predicting the fiber diameter of melt‐blown nonwoven fabrics from the processing parameters. An attempt is made to study the effect of the number of the hidden layers and the hidden layer neurons to minimize the prediction error. The artificial neural network with three hidden layers (5, 2, and 3 neurons in the first, second, and third hidden layer, respectively) yields the minimum prediction error, and thus, is determined as the preferred network. The square of correlation coefficient of measured and predicted fiber diameters shows the good performance of the model. Using the established ANN model, computer simulations of the effects of the processing parameter on the fiber diameter are carried out. The results show great prospects for this research in the field of computer‐assisted design of melt‐blowing technology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4275–4280, 2006
Synthesis and characterization of polyacrylic acid/dexy 85 and polyacrylic acid/gum arabic adducts
Authors: Abo‐Shosha M. H. , Ibrahim N. A. , Allam E. , El‐Zairy M. R. , El‐Zairy E. M.
Published: June 2006

Polyacrylic acid/gum arabic or polyacrylic acid/dextrin (PAA/GA or PAA/D) adducts were prepared by free radical polymerization of highly concentrated, partially neutralized AA using Na2S2O8/Na2S2O3redox system in the presence of GA or D. Optimum reaction conditions, viz., AA, 6.76 mol/L; Na2S2O3, 26.87 × 10−3mol/L; Na2S2O8, 34.9 × 10−3mol/L; degree of neutralization, 20%; temperature, 90°C; and time 30 min, were utilized in preparing two adducts of each substrate (GA or D) at two liquor ratios (LRs; 1.25/1 and 6.3/1L/K). The four adducts formed, viz., PAA/GA1, PAA/GA2,PAA/D1, and PAA/D2(where 1 and 2 refer to the low and high LR, respectively) were found to be water soluble at all proportions. IR spectrum of these adducts confirmed the introduction of the COOH group onto their structures. Rheological properties of 7% aqueous solutions of these adducts, including Na‐alginate (Alg), showed that all are characterized by a non‐Newtonian, shear‐thinning, thixotropic behavior. Within the range of shear rate studied, the apparent viscosities of these solutions followed the descending order: PAA/D2> PAA/D1> Alg > GA1= PAA/GA2. Completing neutralization (Na form) of adducts to 100% results in a remarkable enhancement of their apparent viscosities, so that they follow the descending order, depending on the shear rate:equation imageequation imageequation image© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4290–4300, 2006
Effects of chitosan addition to DMEU‐processed cotton fabrics for adsorbing metallic ions in waste water
Authors: Hsieh Sung Huang , Huang Chih Huang , Chiu Shun Pin
Published: June 2006

This study examines the effects of adding chitosan to the curing treatment of cotton fabrics, using dimethylolethyleneurea as a crosslinking reagent; in particular, how the adsorption of the processed cotton fabrics for metallic ions is influenced. Different concentrations of added chitosan, different curing temperatures and time, as well as different adsorption times and temperatures were examined. The cotton fabrics studied were compared with other adsorptive materials, and also, were examined by Fourier Transform Infrared Analysis (FTIR), Scanning Electronic Microscope (SEM), and Thermal Gravity Analysis (TGA) to study the crosslinkage reaction. The experimental results were as follows: the adsorption of copper and zinc ions increases as chitosan concentration increases, with the best adsorption when chitosan concentration is 0.5%; the adsorption of copper and zinc ions increases as the curing temperature rises, with the best adsorption at 140°C; the adsorption increases with longer curing time, with the best adsorption at 6 min after the processing begins. For adsorption of zinc ions, the cotton fabrics containing chitosan have better adsorption than pure chitosan, but worse adsorption than activated carbon. For the adsorption of copper ions, chitosan is the best, processed cotton fabrics are the second, and activated carbon is the poorest. The adsorption of these two kinds of ions increases with the longer time and higher temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4440–4445, 2006
Relationship between structure and properties of modified potato starch biodegradable films
Authors: Cyras Viviana P. , Tolosa Zenklusen María C. , Vazquez Analía
Published: June 2006

Potato starch was gelatinized in the presence of water and varying amounts of glycerol at 90°C. Starch/glycerol films were prepared by casting with water. The addition of glycerol produces a decrease in the crystallinity of the starch in the films. Starch was acetylated (with acetic acid and anhydride) and maleated (with maleic anhydride). Differential scanning calorimetric analysis revealed decrease in the glass transition temperature (Tg) with the chemical modification. The starch modification on the equilibrium moisture content was determined at 25°C. The esterifications produce a decrease in the maximum moisture sorption. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4313–4319, 2006
Separation of metal ions by water‐insoluble polymers containing sulfonic/sulfonate groups
Authors: Rivas Bernabé L. , Muñoz Carla
Published: June 2006

A water‐insoluble polymer, poly(sodium 4‐styrene sulfonate), was synthesized by radical polymerization at different amounts (2, 4, 6, and 8 mol %) of crosslinking reagent (CR). At the lowest CR level (2 mol %), only a water‐soluble polymer is obtained, and consequently it could not be studied as resin. The polymerization yield ranged from 82.6 to 91.6%. The resin is characterized by FTIR spectroscopy, thermal analysis, and scanning electron microscopy. The metal ion affinity is studied for the cations: Hg(II), Cd(II), Zn(II), Pb(II), Cr(III), and Al(III) with a batch equilibrium procedure under different experimental conditions. The metal ion affinity increased as the pH increased. At pH 5, the resin showed an affinity greater than 97% for all metal ions. Hg(II) showed the highest retention value at pH 2. The maximum retention capacity is determined at optimum pH for Hg(II), Cd(II), Pb(II), and Zn(II). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4328–4333, 2006
Enhanced gas separation properties by using nanostructured PES‐Zeolite 4A mixed matrix membranes
Authors: Huang Zhen , Li Yi , Wen Rui , May Teoh May , Kulprathipanja Santi
Published: June 2006

The polymer–zeolite mixed matrix membranes were fabricated by incorporating nanosized or microsized zeolite 4A into polyethersulfone. A comparison of zeolite 4A nanocrystals and microcrystals was made by using SEM, XRD, N2 adsorption–desorption measurements. Zeolite particles were well‐distributed in the polymer phase, as reflected by the SEM images. The effects of the zeolite 4A particle size on the gas permeation performance were studied. Experimental results demonstrate that mixed matrix membranes exhibit decreased gas permeabilities due to the barrier effect of zeolite particles. The obtained permselectivity is greatly enhanced for He/N2, H2/N2, He/CO2, and H2/CO2 gas pairs, especially for nanosized zeolite 4A mixed matrix membranes. The gas permeation performance difference is observed between the nanostructured and microstructured membranes, which is attributed to a combined effect of different zeolite composition and different particle size. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3800–3805, 2006
Thermal cure of phenylethynyl‐terminated AFR‐PEPA‐4 imide oligomer and a model compound
Authors: Li Yuntao , Morgan Roger J.
Published: June 2006

The thermal cure reactions of phenylethynyl terminated AFR‐PEPA‐4 oligomer and a model compound N‐phenyl‐[4‐(phenylethynyl) phthalimide] were investigated. The kinetics analysis of the thermal cure of AFR‐PEPA‐4 was determined using DSC, with modified DiBenedetto equation. The activation energy of thermal cure reaction of AFR‐PEPA‐4 oligomer is 34.1 kcal/mol with the kinetic order of one, when the reaction conversion is less than 80%. The activation energy of thermal reaction of N‐phenyl‐[4‐(phenylethynyl) phthalimide] is 41.5 kcal/mol with the kinetic order of 0.95. The cure reaction of AFR‐PEPA‐4 imide oligomer can be described as a fast first‐order reaction stage for the formation of polyenes followed by a slow diffusion‐controlled crosslinking reaction stage. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4446–4453, 2006
Cocrystallization mechanism of poly(3‐hexyl thiophenes) with different amount of chain regioregularity
Authors: Pal Susmita , Nandi Arun K.
Published: June 2006

The overall crystallization rates of poly (3‐hexyl thiophene) (P3HT) cocrystals with different amount of regioregularity of the components are measured using differential scanning calorimetry (DSC). Two pairs of cocrystals with varying compositions of the component polymers (viz P3HT(R) (regioregularity 92 mol %)/P3HT‐2 (regioregularity 82 mol %), and P3HT‐2/P3HT‐1 (regioregularity 75 mol %)) are used. The crystallization rate at the same isothermal crystallization temperature (Tc) decreases with increasing regioregularity. The low Avrami exponent values (0.15–1.0) in all the samples suggest the presence of rigid amorphous portion, which cannot diffuse out quickly from the crystal growth front (soft impingement). Analysis of crystallization rate using Laurintzen–Hoffman (L–H) growth rate theory indicates Regime I to Regime II transition in all the samples. The product of lateral and end surface energy values (σσe) increases gradually with increasing regioirregularity in the blend. Analysis of σ values indicates chain extension of the components in the melt of the blend and the entropy of activation (ΔSI–II) of the cocrystals are higher than those of the components. The entropy of cocrystallization (ΔSc) values are 1–2.4 e.u for P3HT(R)/P3HT‐2 system and 0.5–1 e.u for P3HT‐2/P3HT‐1 system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3811–3820, 2006
Plasma modification of cellulose fibers for composite materials
Authors: Morales J. , Olayo M. G. , Cruz G. J. , Herrera‐Franco P. , Olayo R.
Published: June 2006

Composites of natural fibers and thermoplastics can be combined to form new enhanced materials. One of the problems involved in this type of composites is the formation of chemical bonds between the fibers and the polymers at the interface. This work presents a study where low energy glow discharge plasmas are used to functionalize cellulose fibers implanting polystyrene between the fibers and the matrix that improve the adhesion of both components. The interface of polystyrene was synthesized by continuous and periodic glow discharges on the surface of the cellulose fibers. The results show that the adhesion in the fiber–matrix interface increases with time in the first 4 min of treatment. However, at longer plasma exposures, the fiber may be degraded reducing the adhesion with the matrix. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3821–3828, 2006
Blue light‐emitting poly(p‐phenylenevinylene) derivative with oxadiazole and carbazole pendant groups
Authors: Mikroyannidis John A.
Published: June 2006

A blue light‐emitting statistical poly(p‐phenylenevinylene) (PPV) copolymer with hole‐transporting carbazole and electron‐transporting oxadiazole pendant groups attached to the kinked m‐terphenyl unit was prepared by Heck coupling between 1,4‐divinylbenzene and dibromides. The latter were synthesized through pyrylium salts. The polymer had optical band gap of 2.89 eV and emission maximum at 446 nm in THF solution and 434 nm in thin film. It showed a pure blue emission with no aggregates or excimers formed even in solid state because of the long and bulky pendant groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3842–3849, 2006
Molecularly imprinted polymer membranes for substance‐selective solid‐phase extraction from aqueous solutions
Authors: Zhu Xiaolan , Su Qingde , Cai Jibao , Yang Jun , Gao Yun
Published: June 2006

Thin‐layer molecularly imprinted polymer (MIP) composite membranes for selective binding of monocrotophos (MCP) pesticide from aqueous solutions were developed. The procedure was based on commercially available membrane modules that were rinsed with prepolymerization imprinting mixtures. After the in situ polymerization and generation of MIP films on the membranes within the modules, the membranes were evaluated in terms of affinity toward the target molecule MCP. MIP membranes with different porogens and different monomers on Nylon‐6 membranes were prepared. It was shown that MIP membranes synthesized with methacrylic acid as monomer and toluene as porogens on the Nylon‐6 membranes provided a highly selective binding of MCP from aqueous solutions under the optimized elution conditions. With the novel surface modification technique, the low nonspecific binding properties of the microfiltration membrane could successfully be combined with the receptor properties of molecular imprints, yielding substance‐specific MIP composite membranes. The high affinity of these synthetic membranes to MCP pesticide together with their straightforward and inexpensive preparation could be applied in a fast preconcertration step, solid‐phase extraction, by a simple microfitration for the determination of MCP in water. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4468–4473, 2006
Dipolar chains and 2D aligned stripes of polymer‐coated magnetic iron colloid
Authors: Yan Lifeng , Shen Sui , Li Wan , Wang Xiaoping
Published: June 2006

Studies on the self‐assembly of core–shell magnetic nanospheres under or without an external magnetic field are the subject of intense research. It is believed that after being coated by organic molecules, the magnetic nanoparticles can still have chance to form chain‐like structure driven by the dipole–dipole interactions while the coated shell minimizes the effect of Van der Waals attractions. However, still there are no direct experimental observations for polymer‐modified magnetic colloids sized hundreds of nanometers. In this article, PEG‐ and PSt‐coated Fe2O3 nanospheres were synthesized and their self‐assembly behaviors were studied. MFM and TEM measurements reveal that the prepared spheres owning a core–shell structure. Under zero magnetic field, a direct observation of chain‐like structure was achieved for the PEG‐coated magnetic colloids. For the PSt‐modified magnetic spheres, there formed a 2D aligned stripes pattern at the surface of mica when the suspending of sample was dried under an external magnetic field. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4211–4215, 2006
High PVC film‐forming composite latex particles via miniemulsification, part 1: Preparation
Authors: Al‐Ghamdi Ghurmallah H. , Sudol E. David , Dimonie Victoria L. , El‐Aasser Mohamed S.
Published: June 2006

Miniemulsification technology was used to encapsulate TiO2 particles inside a styrene/n‐butyl acrylate copolymer with high loading levels (11 to 70% PVC (pigment volume concentration)). In this approach, a St/BA copolymer dissolved in toluene in the presence of a costabilizer (hexadecane) was mixed with a dispersion of TiO2 particles in toluene and sonified, and then emulsified in an aqueous surfactant solution by sonification. The effect of sonification time on both the dispersibility of the TiO2 particles in the presence of the copolymer and hexadecane and on the encapsulated particle size was investigated. Particle size analysis by dynamic light scattering showed that these composite latexes are quite stable. It was also found that as the TiO2 loading increased from 11 to 43% PVC, the particle size of the TiO2 dispersion decreased while the polymer‐encapsulated TiO2 particle size increased. The effect of surfactant concentration (sodium lauryl sulfate, SLS) on the encapsulated particle size was investigated using four different SLS concentrations in the 11% PVC system. The results showed that as the SLS concentration increased the particle size decreased, as expected. Also it was found that the minimum surfactant concentration that gives stable encapsulated TiO2 particles is above 10 mM SLS. The role of HD in the recipe was studied for an artificial latex containing no TiO2 and one prepared at 11% PVC, in terms of particle size before and after solvent stripping, and its effect on the Tg. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4504–4516, 2006
Effect of various plasticizers on the transport properties of hexanoyl chitosan‐based polymer electrolyte
Authors: Winie Tan , Arof A. K.
Published: June 2006

Hexanoyl chitosan that exhibited solubility in tetrahydrofuran was prepared by acyl modification of chitosan. Films of hexanoyl chitosan‐based polymer electrolyte were prepared by the technique of solution casting. Ethylene carbonate, propylene carbonate, and diethyl carbonate with different dielectric constants were employed as the plasticizing solvents and lithium trifluoromethanesulfonate (LiCF3SO3) was used as the salt. The importance of dielectric constant affecting conductivity and transport properties of hexanoyl chitosan:LiCF3SO3 electrolytes have been examined in the present study. An enhancement in the ionic conductivity has been found on plasticization, and the magnitude of conductivity increment strongly depended on the dielectric constant of the plasticizer. Transport properties such as activation energy and charge carrier concentration have been calculated to obtain information that may be used to elucidate the mechanism of conductance. In addition to conductivity studies, thermal studies and transference number measurements were performed to correlate the phase structure and diffusion phenomena to the conductivity behavior of hexanoyl chitosan‐based polymer electrolyte. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101:4474–4479, 2006
Fundamental parameters affecting electrospinning of PAN nanofibers as uniaxially aligned fibers
Authors: Jalili Rouhollah , Morshed Mohammad , Ravandi Seyed Abdolkarim Hosseini
Published: June 2006

Electrospinning with a collector consisting of two pieces of electrically conductive substrates separated by a gap has been used to prepare uniaxially aligned PAN nanofibers. Solution of 15 wt % of PAN/DMF was used tentatively for electrospinning. The effects of width of the gap and applied voltage on degree of alignment were investigated using image‐processing technique by Fourier power spectrum method. The electrospinning conditions that gave the best alignment of nanofibers for 10–15 wt % solution concentrations were experimentally obtained. Bundles like multifilament yarns of uniaxially aligned nanofibers were prepared using a new simple method. After‐treatments of these bundles were carried out in boiling water under tension. A comparison was made between the crystallinity and mechanical behavior of posttreated and untreated bundles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4350–4357, 2006
Physical properties of electron beam irradiated poly(vinyl butyral) composites with carbamate, imidazole, and tetrazolium dye
Authors: Said Hossam M. , Ali Z. I. , Ali Hussein E.
Published: June 2006

Films of poly(vinyl butyral) composites with triphenyl tetrazolium chloride dye (TTC) and the antioxidant nickel dibutyl dithiocarbamate (NBC) or 2‐mercaptobenzimidazole (MBI) were prepared by the solution casting method using butyl alcohol as a solvent. The effect of various doses of electron beam irradiation (50–200 kGy) on color response, thermal, and mechanical properties were investigated. The color measurements showed that the films of the different composites possessed a high sensitivity to electron beam irradiation, in which the nearly colorless films were changed to deep red color, which can be easily detected by visual observations. In addition, the change in color depends on irradiation dose and the contents of the TTC dye. Moreover, the presence of the antioxidants NBC or MBI has no effect on the development of color. However, PVB/TTC and PVB/TTC/MBI composites showed high regular change in color as a function of irradiation dose. The thermogravimetric analysis used to study the thermal stability indicated that PVB/TTC composites either before or after electron beam irradiation are thermally more stable than neat PVB polymer. The presence of the antioxidants NBC or MBI offered protection to PVB/TTC composites against decomposition or oxidative degradation resulted from irradiation. Blending unirradiated PVB with TTC dye, mixture of TTC and NBC, and mixture of TTC and MBI reduced the tensile strength by 4, 20, and 17% upon blending, respectively. However, the reduction in tensile strength of the entire composite films (∼7% based on the initial value) upon exposure to a dose of 50 kGy is acceptable for practical applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4358–4365, 2006
Investigation on preparation and property of nano‐CaCO3/PP masterbatch modified by reactive monomers
Authors: Zhidan Lin , Zishou Zhang , Zhenzhen Huang , Kancheng Mai
Published: June 2006

Nano‐CaCO3/polypropylene (PP) masterbatch containing above 80 wt % nano‐CaCO3 was prepared by nano‐CaCO3 coated PP modified by reactive monomers. The chemical interaction, crystallization and melting behavior, thermal stability, morphology, and surface contact angle of masterbatch were investigated with IR, DSC, TEM, TGA, ESCA, and surface contact angle. The results indicated that nano‐CaCO3 was coated by PP graft copolymers in the masterbatch modified by reactive monomers. The graft ratio and crystallization and melting behavior of PP in the masterbatch depended on the type and content of reactive monomer. The crystallization temperatures of masterbatch modified by reactive monomer is methyl methacrylate > butyl acrylate > methyl acrylate ≈ mixture of acrylic acid and styrene > unmodified ≈ maleic anhydride ≈ acrylic acid > styrene. Modification by reactive monomer increased the thermal stability and surface contact angle of masterbatch. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3907–3914, 2006
The conversion of calcium alginate fibers into alginic acid fibers and sodium alginate fibers
Authors: Qin Yimin , Hu Huiqun , Luo Aixiang
Published: June 2006

Alginate is a natural polymer extracted from brown seaweeds. Over the last two decades, alginate fibers have become well established in the wound management industry where their ion exchange and gel forming abilities are particularly useful in the treatment for exuding wounds. Alginate fibers are commonly made by extruding sodium alginate solution into a calcium chloride bath, producing calcium alginate fibers. To improve the gelling ability and the absorption capacity of calcium alginate fibers, this study used hydrochloric acid to convert calcium alginate fibers into alginic acid fibers, which was further converted into sodium alginate fibers by treating the fibers with sodium hydroxide in organic solvent. Results showed that alginic acid and sodium alginate fibers and fabrics can be readily made by treating the calcium alginate fibers and fabrics, respectively, with hydrochloric acid and sodium hydroxide. Improved gel blocking properties and absorption capacities were obtained with the sodium alginate fibers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4216–4221, 2006
Synthesis and properties of brominate bismaleimide monomers
Authors: Sava M.
Published: June 2006

Brominated bismaleimides were prepared by reacting 3(4)‐maleimidobenzoylchloride with various bisphenols, using chloroform as solvent and triethylamine as acid acceptor. These monomers were characterized by elemental analysis, infrared (IR), and proton nuclear resonance (1H‐NMR) spectroscopy. Thermal properties of monomers were accomplished by differential scanning calorimetry (DSC) and dynamic thermogravimetric analysis (ATG). The properties of these compounds were compared with those of monomers derived from bisphenol A and bisphenol A chlorinated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3881–3885, 2006
Cure kinetics of aqueous phenol–formaldehyde resins used for oriented strandboard manufacturing: Effect of zinc borate
Authors: Lei Yong , Wu Qinglin
Published: June 2006

The effect of zinc borate (ZB) on the cure kinetics of commercial phenol–formaldehyde oriented strandboard adhesives was studied using differential scanning calorimetry. ZB caused a separation of the addition and condensation reactions for both face and core resin (CR) systems with lowered cure temperature for the addition reaction. For the face resin, ZB did not change its nth‐order curing mechanism, but retarded the whole cure reactions, and increased the reaction order and the activation energy. Compared with neat CR, the addition reaction of the CR/ZB mixture, which occurred at temperatures lower than 60°C, also followed an nth‐order reaction mechanism. The condensation reaction of the mixture was changed from an autocatalytic reaction to an nth‐order one with the reaction order of about 1. The proposed models fitted the experimental data well. Relationships among cure reaction conversion (i.e., cure degree), cure temperature, and cure time were predicted for various resin/ZB systems. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3886–3894, 2006
Stiffness and strength of asymmetric laminates made of isotropic PCBA and PMMA layers
Authors: Papadopoulos G. A. , Sideridis E.
Published: June 2006

In this work the stiffness and strength of a composite material in the form of an asymmetric laminate are obtained from the properties of the constituent laminae made of isotropic layers, Lexan (PCBA) and Plexiglas (PMMA). The influence of the stacking sequence of the laminate and the interface between the laminae that affects the mechanical properties are investigated. A theoretical analysis based on the lamination theory was performed to determine the stress and strain distribution as well as the elastic constants. Experimental measurements with specimens made of asymmetric laminates of various stacking sequences were carried out. The obtained values were compared with the theoretical values given by the lamination theory and mechanics of materials approach. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4493–4503, 2006
Development of antimicrobial polypropylene sutures by graft polymerization. I. Influence of grafting conditions and characterization
Authors: Anjum Nishat , Gulrez S. K. H. , Singh Harpal , Gupta Bhuvanesh
Published: June 2006

Modification of polypropylene monofilament was carried out by the graft polymerization of 1‐vinylimidazole (VIm) using simultaneous radiation grafting method. The effect of radiation dose, monomer concentration, and the grafting medium on the degree of grafting was evaluated. It was observed that the presence of organics as additives in the reaction medium had significant influence on the graft levels. These grafted sutures were characterized using several techniques, such as infrared spectroscopy (IR), X‐ray diffraction, and differential scanning calorimetry (DSC). It was found that the grafts are confined to the amorphous region of the monofilament and the crystalline regions remain intact. The surface morphology of sutures was evaluated by scanning electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3895–3901, 2006
Nonlinear viscoelastic properties of molten thermoplastic vulcanisates: An insight on their morphology
Authors: Leblanc Jean L.
Published: June 2006

A series of thermoplastic vulcanisates (TPVs) in the molten state were submitted to large amplitude oscillating strain tests at different frequencies, to investigate their nonlinear viscoelastic properties. A purposely modified torsional harmonic tester with a closed cavity was used to run such experiments, whose results were treated with a Fourier transform (FT) algorithm to extract main torque and strain components, and harmonics if any. Quarter cycle integrations of (averaged) torque signal were also performed, to supplement FT analysis, namely to distinguish extrinsic and intrinsic nonlinear viscoelasticity. The nonlinear viscoelastic character of TPVs was found substantially differing from the one of a molten polypropylene (PP) used for comparison. Within the strain window investigated, no linear behavior is observed with TPVs, in contrast with the pure PP. However, extrapolated “linear” complex modulus G*0 tends to decrease with increasing hardness of TPVs, but subtle differences between the various grades are clearly detected, when using simple models to fit experimental data. While the (room temperature) hardness is somewhat related with the viscoelastic behavior in the molten state, the strain sensitivity of TPVs appears essentially affected by the extractible content (mainly oil). TPVs nonlinear viscoelastic character appears to depend on the strain amplitude: mainly intrinsic, i.e., due to their morphology, at low strain, and essentially extrinsic, i.e., due to the large strain amplitude, at high strain, and in this respect, qualitatively similar to pure PP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4193–4205, 2006
Systemic sclerosis–associated Sjögren's syndrome and relationship to the limited cutaneous subtype: Results of a prospective study of sicca syndrome in 133 consecutive patients
Authors: Avouac J. , Sordet C. , Depinay C. , Ardizonne M. , Vacher‐Lavenu M. C. , Sibilia J. , Kahan A. , Allanore Y.
Published: June 2006

Objective

To determine the prevalence of sicca symptoms and Sjögren's syndrome (SS) in a 2‐center prospective series of patients with systemic sclerosis (SSc), using the American–European Consensus Group criteria for SS.

Methods

Consecutive SSc patients hospitalized for followup care were evaluated for sicca symptoms. When the initial clinical evaluation yielded positive findings, a labial salivary gland biopsy was performed; histologic analysis evaluated focal lymphocytic sialadenitis and/or glandular fibrosis. Computed tomography and respiratory function tests were used to assess pulmonary fibrosis.

Results

We included 133 SSc patients (mean ± SD age 55 ± 13 years; mean ± SD disease duration 6.5 ± 6 years). Eighty‐one patients had limited cutaneous SSc (lcSSc). Ninety‐one patients (68%) had sicca syndrome. Histologic analysis revealed fibrotic involvement in 50 of these 91 patients, but labial salivary gland fibrosis was not associated with any organ involvement we evaluated. Nineteen of the 133 patients (14%) had SS. In this subgroup, lcSSc was present at a significantly higher frequency (18 of 19 patients) than in the remaining patients with sicca syndrome (39 of 72 patients) and the patients without sicca syndrome (24 of 42 patients). This subgroup also had a significantly higher frequency of anticentromere antibodies (18 of 19 patients) than did the remaining patients with sicca syndrome (19 of 72 patients) and the patients without sicca syndrome (5 of 42 patients). In addition, this subgroup had a significantly lower prevalence of pulmonary fibrosis (2 of 19 patients) than did the remaining patients with sicca syndrome (29 of 72 patients) and the patients without sicca syndrome (19 of 42 patients).

Conclusion

There was a 68% prevalence of sicca syndrome in this prospective series of SSc patients. Sicca syndrome was related primarily to glandular fibrosis, the hallmark of SSc. The prevalence of secondary SS, as defined by the American–European Consensus Group criteria, was 14% and was markedly associated with lcSSc. We believe that lcSSc should be regarded as a specific autoimmune subgroup of SSc.
Nephritogenic Anti‐DNA antibodies regulate gene expression in MRL/lpr mouse glomerular mesangial cells
Authors: Qing Xiaoping , Zavadil Jiri , Crosby Michelle B. , Hogarth Mark P. , Hahn Bevra H. , Mohan Chandra , Gilkeson Gary S. , Bottinger Erwin P. , Putterman Chaim
Published: June 2006

Objective

Lupus‐associated IgG anti–double‐stranded DNA antibodies are thought to be pathogenic in the kidney due to cross‐reaction with glomerular antigens, leading subsequently to immune complex formation in situ and complement activation. We undertook this study to determine if pathogenic anti‐DNA antibodies may also contribute to renal damage by directly influencing mesangial gene expression.

Methods

Complementary DNA microarray gene profiling was performed in primary mesangial cells (derived from lupus‐prone MRL/lpr mice) treated with pathogenic, noncomplexed anti‐DNA antibodies. Significant gene up‐regulation induced by anti‐DNA antibodies as determined by microarray analysis was further investigated by real‐time polymerase chain reaction and methods to detect the relevant proteins. Induction of proinflammatory genes by pathogenic antibodies was confirmed by comparing gene expression in glomeruli of old versus young MRL/lpr mice, and by antibody injection in vivo.

Results

Pathogenic, but not nonpathogenic, antibodies significantly induced a number of transcripts, including CXCL1/KC, LCN2, iNOS, CX3CL1/fractalkine, SERPINA3G, and IκBα (“marker genes”). Blocking of Fcγ receptors or using Fcγ chain–knockout mesangial cells had no effect on the gene regulation effect of the pathogenic antibody R4A, indicating a non–Fc‐dependent mechanism. The glomerular expression of these marker genes increased over time with the development of glomerular antibody deposition and active nephritis in MRL/lpr mice. Moreover, injection of R4A into SCID mice in vivo significantly up‐regulated glomerular marker gene expression.

Conclusion

These findings indicate that the renal pathogenicity of anti‐DNA antibodies may be attributed in part to their ability to directly modulate gene expression in kidney mesangial cells through both Fc‐dependent and non–Fc‐dependent mechanisms.
Identification of transitional type II B cells in the salivary glands of patients with Sjögren's syndrome
Authors: Daridon Capucine , Pers Jacques‐Olivier , Devauchelle Valérie , Martins‐Carvalho Christine , Hutin Pascal , Pennec Yvon‐Louis , Saraux Alain , Youinou Pierre
Published: June 2006

Objective

To identify B cell subpopulations participating in the lymphocyte infiltrate of salivary glands from patients with primary Sjögren's syndrome. A special emphasis was placed on those B lymphocytes included in the ectopic germinal centers (GCs).

Methods

The presence of B cells in salivary glands and their polyclonality were ascertained by phenotyping and reverse transcription–polymerase chain reaction in salivary gland samples from 18 patients. Their phenotype was thoroughly analyzed using a number of double‐staining combinations. The results obtained in tissue sections were confirmed by fluorescence‐activated cell sorting analysis of B cells eluted from salivary glands, and these findings were compared with those in tonsils.

Results

Memory‐type B cells were defined as CD20+,CD27+ and were seen in all specimens, whereas GCs were found in only 7 specimens. Furthermore, B cells found in these GCs lacked certain characteristics of centroblasts and centrocytes. Instead, they fulfilled the criteria for transitional type II (TII) B cells and resembled marginal‐zone B cells. BAFF (the assistance of which is required for proper transformation of transitional TI B cells into transitional TII B cells) accumulated adjacent to transitional and marginal‐zone–like B lymphocytes. Further evidence for the involvement of BAFF came from the expression of its receptors on infiltrating B cells.

Conclusion

These transitional TII and marginal‐zone–like B cells are probably instrumental in the local production of autoantibodies and possibly influential in the ensuing destruction of epithelial cells.
Association between enhanced type I collagen expression and epigenetic repression of the FLI1 gene in scleroderma fibroblasts
Authors: Wang Youngqing , Fan Pan‐Sheng , Kahaleh Bashar
Published: June 2006

Objective

Scleroderma (systemic sclerosis; SSc) is an autoimmune disease characterized by vasculopathy and widespread organ fibrosis. Altered fibroblast function, both in vivo and in vitro, is well documented and illustrated by augmented synthesis and deposition of extracellular matrix proteins. We undertook this study to investigate the possibility that epigenetic mechanisms mediate the emergence and persistence of the altered SSc fibroblast phenotype.

Methods

The effects of DNA methyltransferase and histone deacetylase inhibitors on collagen expression and the level of epigenetic mediators in fibroblasts were examined. The effects of transient transfection of SSc fibroblasts with FLI1 gene and normal cells with FLI1 antisense construct on collagen expression were determined. The methylation status of the FLI1 promoter was tested in cultured cells and in SSc and normal skin biopsy specimens.

Results

Increased levels of epigenetic mediators in SSc fibroblasts were noted. The addition of epigenetic inhibitors to cell cultures normalized collagen expression in SSc fibroblasts. The augmented collagen synthesis by SSc fibroblasts was linked to epigenetic repression of the collagen suppressor gene FLI1. Heavy methylation of the CpG islands in the FLI1 promoter region was demonstrated in SSc fibroblasts and skin biopsy specimens.

Conclusion

The results of this study indicate that epigenetic mechanisms may mediate the fibrotic manifestations of SSc. The signal transduction leading to the SSc fibrotic phenotype appears to converge on DNA methylation and histone deacetylation at the FLI1 gene.
A randomized controlled trial of calcium supplementation to increase bone mineral density in children with juvenile rheumatoid arthritis
Authors: Lovell Daniel J. , Glass David , Ranz Julie , Kramer Sandy , Huang Bin , Sierra Rosa I. , Henderson Carol J. , Passo Murray , Graham Brent , Bowyer Suzanne , Higgins Gloria , Rennebohm Robert , Schikler Kenneth N. , Giannini Edward
Published: June 2006

Objective

To examine the effects of daily supplementation with calcium (Ca) in combination with vitamin D on total body and lumbar spine bone mineral density (BMD) in patients with juvenile rheumatoid arthritis (JRA) who had not taken corticosteroids for at least 3 months prior to the beginning of the study.

Methods

One hundred ninety‐eight children and adolescents (141 girls and 57 boys) with JRA, ages 6 to 18 years, with a mean ± SD age of 11.7 ± 3.3 years and a mean ± SD disease duration of 5.6 ± 3.8 years at the beginning of the study, were enrolled in this randomized double‐blind, placebo‐controlled trial to receive either daily oral supplements of 1,000 mg of Ca and 400 IU of vitamin D (n = 103) or matched placebo tablets and 400 IU of vitamin D (n = 95) for 24 months. Total body BMD (TBBMD) was measured by dual x‐ray absorptiometry at baseline and every 6 months for 24 months.

Results

At baseline, the mean ± SD TBBMD was 0.89 ± 0.14 gm/cm2 among patients randomized to the Ca group and 0.87 ± 0.14 gm/cm2 among those randomized to placebo (P = 0.445). At 24 months, the mean ± SD TBBMD among those receiving Ca was 0.95 ± 0.13 gm/cm2, compared with 0.92 ± 0.14 gm/cm2 among those receiving placebo. A longitudinal random‐effects mixed model analysis that controlled for differences in the subject's initial BMD, sex, Tanner stage, adherence to the study medication regimen, and body composition revealed significantly higher TBBMD among patients who received Ca compared with patients who received placebo during the study period (P = 0.03).

Conclusion

Ca supplementation resulted in a small, but statistically significant, increase in TBBMD compared with placebo in children with JRA.
Manipulation of isoprenoid biosynthesis as a possible therapeutic option in mevalonate kinase deficiency
Authors: Schneiders Marit S. , Houten Sander M. , Turkenburg Marjolein , Wanders Ronald J. A. , Waterham Hans R.
Published: June 2006

Objective

In cells from patients with the autoinflammatory disorder mevalonate kinase (MK) deficiency, which includes the hyperimmunoglobulin D with periodic fever syndrome, MK becomes the rate‐limiting enzyme in the isoprenoid biosynthesis pathway. This suggests that up‐regulation of residual MK activity in these patients could be a way in which to prevent or alleviate the associated symptoms. We studied the effect of 2 specific inhibitors of isoprenoid biosynthetic enzymes on the residual activity of MK in cells from patients with MK deficiency.

Methods

Skin fibroblasts from MK‐deficient patients and from controls were cultured for 7 days with either simvastatin, an inhibitor of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase, or zaragozic acid A, an inhibitor of squalene synthase. Following culture, MK activity, MK protein levels, MVK messenger RNA levels, and the effect on the pathway flux toward nonsterol isoprenoid biosynthesis were determined.

Results

Treatment of the fibroblasts with either of the inhibitors led to a marked increase in residual MK enzyme activity, which was largely attributable to increased MVK gene transcription. This effect was even more pronounced when the cells were cultured in lipoprotein‐depleted medium. The flux toward nonsterol isoprenoid end‐product synthesis was reduced when cells were treated with simvastatin but was partly restored by concomitant treatment with zaragozic acid A.

Conclusion

Our results indicate that manipulations of the isoprenoid biosynthesis pathway that promote the synthesis of nonsterol isoprenoids may provide an interesting therapeutic option for the treatment of MK deficiency.
A severe case of chronic infantile neurologic, cutaneous, articular syndrome treated with biologic agents
Authors: Matsubara Tomoyo , Hasegawa Masanari , Shiraishi Masahiro , Hoffman Hal M. , Ichiyama Takashi , Tanaka Takeo , Ueda Haruo , Ishihara Tokuhiro , Furukawa Susumu
Published: June 2006

In this report we describe a case of severe chronic infantile neurologic, cutaneous, articular (CINCA) syndrome with a novel G307V cryopyrin mutation and all of the characteristic clinical and laboratory features of this autoinflammatory disease. There was no clear response to standard therapies, including human interleukin‐1 (IL‐1) receptor antagonist (anakinra) and soluble tumor necrosis factor receptor (etanercept). The patient finally had a partial clinical response (reduction in fever and irritability) and complete laboratory response (improved C‐reactive protein and serum amyloid A levels) to humanized anti–IL‐6 receptor antibody (MRA), but died from congestive heart failure and interstitial pneumonia 2 months after initiation of therapy. We serially measured the serum cytokine levels and expression of NF‐κB activation in the patient's peripheral blood mononuclear cells before and during consecutive therapies. Pathologic examination of autopsy specimens was also performed. This case illustrates the continued difficulty in management of patients with CINCA syndrome and the complexity of the inflammatory pathways in this disorder.