bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiation crosslinking of biodegradable carboxymethylchitin and carboxymethylchitosan
Authors: Wasikiewicz J. M. , Mitomo H. , Nagasawa N. , Yagi T. , Tamada M. , Yoshii F. 
Published: July 2006

AbstractRadiation induced crosslinking of carboxymethylchitin (CMCht) and carboxymethylchitosan (CMChts) has been investigated both by electron beam (EB) and γ‐irradiations. The highest crosslinking efficiency, measured as gel content of obtained hydrogels, by EB irradiation was 72 and 50% for CMCht and CMChts, respectively, at polymer concentration of 40% at room temperature. For irradiation crosslinking at different temperatures by γ‐irradiation, the best ratio of crosslinking to degradation processes was obtained at low temperature for low concentrated polymers and at high temperature for high concentrated ones. Both hydrogels revealed significant swelling properties in deionized water, with maximum water uptake 241.2 and 63 g water/g dry gel for CMCht and CMChts, respectively. Biodegradation tests, including enzymatic controlled microorganisms degradations and soil burial, have indicated that both hydrogels undergo spontaneous biodegradation with satisfactory results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 758–767, 2006
Fire‐retardant properties of the viscose rayon containing alkoxycyclotriphosphazene
Authors: Chen Sheng , Zheng Qing‐kang , Ye Guang‐dou , Zheng Guang‐kong 
Published: July 2006

AbstractThe viscose rayon containing cyclotriphosphazene were prepared by the method of blending spinning. The combustibility and thermal stability of the fire‐retardant viscose rayon were evaluated by 45 ° slope burning method, limit oxygen index (LOI), differential scanning calorimetry, thermogravimetry analysis. The results indicated that the LOI of the modified fiber could reach LOI ≥ 28, and the combustibility of the modified fiber could reach the fire‐retardant standard of Japan industry standard JIS 10 91–77 (times of ignition ≥ 3 times). The analysis of the fiber's thermal degradation suggested that the flame retardant plays a multirole of heat absorption, catalytic dehydration and carbonization, condensation‐phase and gas‐phase flame retardation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 698–702, 2006
γ‐Irradiation effects on the thermal and structural characteristics of modified, grafted polypropylene
Authors: Khalil Magda M. I. , El‐Sawy Naeem M. , El‐Shobaky Gamil A. 
Published: July 2006

AbstractThe effects of both the degree of grafting and γ irradiation on the thermal stability and structural characteristic of polypropylene‐graft‐polyvinylpyrrolidone and polypropylene‐graft‐polyvinylpyrrolidone modified with α‐cyano‐δ‐(2‐thienyl) crotononitrile were investigated. The employed techniques were thermogravimetric analysis, differential thermogravimetry, and X‐ray diffraction. The thermal stability of various polymeric substrates was investigated through the determination of the degradation temperature and activation energy of degradation. The effects of different parameters on the structural characteristics of different films were investigated through the determination of possible changes in the degree of ordering of the polymeric substrates. The results revealed that the thermal stability of the trunk polymer, grafted polymer, and polymer modified by α‐cyano‐δ‐(2‐thienyl) crotononitrile increased progressively with an increasing degree of grafting. The increase was, however, more pronounced for the sample undergoing the lowest degree of grafting. The activation energy of the thermal degradation process remained almost unchanged, and this indicated that the degradation processes of the different films followed almost the same mechanism. The γ irradiation at a dose of 60 kGy of the sulfur‐treated polymeric films [i.e., the polymeric films treated with α‐cyano‐δ‐(2‐thienyl) crotononitrile] reduced their thermal stability. This conclusion was reached by the consideration of the changes observed in the pre‐exponential factor of the Arrhenius equation due to different chemical and γ‐irradiation treatments. The degree of ordering, evidenced by X‐ray diffraction measurements of the trunk polymer, grafted polymer, and modified polymer, suffered a significant drop. This drop was much more pronounced for the sulfur‐containing polymeric materials. The observed drop in the degree of ordering of the polymeric substrates was taken as a measure of the structure collapse due to a certain treatment (degree of grafting and sulfur inclusion). The γ irradiation of the sulfur‐containing polymeric materials greatly increased their degree of ordering, which reached a value greater than that measured for the trunk polymer. Therefore, it was concluded that the thermal stability increased as the degree of ordering decreased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 506–515, 2006
Synthesis of polyethylene oxide hydrogels by electron radiation
Authors: Branca C. , Magazù S. , Maisano G. , Auditore L. , Barnà R. C. , De Pasquale D. , Emanuele U. , Trifirò A. , Trimarchi M. 
Published: July 2006

AbstractPoly(ethylene oxide) (PEO) hydrogels were prepared by crosslinking of aqueous PEO 35,000 solutions at a 30% concentration by using electron irradiation. Measurements were performed at different dose rates and irradiation doses. The swelling properties of each sample have been investigated and the network properties of the PEO hydrogels calculated. In particular, the effect of dose rate and dose irradiation on the crosslinking density were investigated. Finally, the experimental results illustrating the effects of the beam parameters on the network properties for a pulsed irradiation are compared to those of a continuum beam. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 820–824, 2006
Ion exchange properties of carboxylated bagasse
Authors: Nada Abd‐Allah M. A. , Hassan Mohammad L. 
Published: July 2006

AbstractBagasse fibers were chemically modified with the aim to prepare lignocellulosic materials that have the ability to remove heavy metal ions from waste water. Three different reactions were used for the modification: etherification using monochloroacetic acid, esterification using succinic anhydride, and oxidation using sodium periodate and sodium chlorite. Bagasse was crosslinked using epichlorohydrin before chemical modification to avoid loss of its constituents during the chemical modification or application. The structure of the prepared derivatives was proofed using Fourier transform infrared and chemical methods. The ability of the prepared bagasse cation exchangers to adsorb heavy metal ions (Cu2+, Ni2+, Cr3+, Fe3+), on a separate basis or in a mixture of them, at different metal ion concentration was tested. Thermal stability of the different bagasse derivatives was studied using thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1399–1404, 2006
ABA triblock copolymers from poly(p‐dioxanone) and poly(ethylene glycol)
Authors: Yang Ke‐Ke , Zheng Li , Wang Yu‐Zhong , Zeng Jian‐Bing , Wang Xiu‐Li , Chen Si‐Chong , Zeng Qiang , Li Bin 
Published: July 2006

AbstractPoly(p‐dioxanone)–poly(ethylene glycol)–poly(p‐dioxanone) ABA triblock copolymers (PEDO) were synthesized by ring‐opening polymerization from p‐dioxanone using poly(ethylene glycol) (PEG) with different molecular weights as macroinitiators in N2 atmosphere. The copolymer was characterized by 1H NMR spectroscope. The thermal behavior, crystallization, and thermal stability of these copolymers were investigated by differential scanning calorimetry and thermogravimetric measurements. The water absorption of these copolymers was also measured. The results indicated that the content and length of PEG chain have a greater effect on the properties of copolymers. This kind of biodegradable copolymer will find a potential application in biomedical materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1092–1097, 2006
Transverse alignment of liquid crystalline epoxy resin on carbon fiber surface
Authors: Lee Jun Yeob 
Published: July 2006

AbstractTransverse alignment of liquid crystalline epoxy (LCE) resin was effectively induced on carbon fiber (CF) surface by amine treatment. Aliphatic and aromatic amines were grafted on oxidized CF surface, and anisotropic orientation of LCE network was identified with X‐ray diffraction and it was correlated with mechanical properties of CF/LCE composites. Vertical alignment of LCE enhanced the transverse dynamic modulus of the composite. Especially, aromatic diamines were effective in promoting the interfacial adhesion as well as transverse composite modulus. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 684–689, 2006
Solvents effect in horseradish peroxidase catalyzed modification of UHMWPE fiber
Authors: Fan Guoning , Zhao Jingchan , Yuan Hongan , Guo Zhian , Wang Junlong , Liang Guozheng 
Published: July 2006

AbstractGraft copolymerization of acrylamide onto ultrahigh molecular weight polyethylene (UHMWPE) using horseradish peroxidase as catalyst was performed in different reaction solution to study the solvent effect. The factors affecting the grafting effect such as the solvents composition, initiator, reaction temperature, and reaction time were investigated. The grafted UHMWPE fiber surface was characterized by IR spectrum, scanning electron microscopy, thermal analysis, contact angle measurement, and single fiber pull out test. Polar groups such as CO and NH2 are approved to appear on the surface after treatment. The contact angle with water decreased from 85 to 50, indicating the wettability of the fiber has been increased. The surface of the grafted fiber became rougher and its adhesion to resin increased significantly, and hence is expected to produce reinforced plastics with resin. It was also found that the grafting effect was higher in dioxane than in other solvents used and the initiator substituted by electron donating group facilitates the grafting reaction. And the optimum reaction condition was determined to be reacting in 40% (v/v) dioxane solution at 30°C for 2 h. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 674–678, 2006
Preparation and characterization of poly(vinyl chloride)/layered double hydroxides nanocomposite via in situ suspension polymerization
Authors: Bao Yong‐Zhong , Huang Zhi‐Ming , Weng Zhi‐Xue 
Published: July 2006

AbstractPoly(vinyl chloride)/layered double hydroxides (PVC/LDHs) composite resins were prepared by in situ suspension polymerization of vinyl chloride monomer in the presence of LDHs intercalated with dodecyl sulfate anions (LDH‐DS), and were further processed to obtain PVC/LDH‐DS nanocomposites. It was found that the mean particle size of PVC composite resins decreased as LDH‐DS was added in the polymerization system. The 5 and 10% weight loss temperatures of PVC resins significantly increased with the increase of LDH‐DS weight fraction in the composite resins. The transmission electron microscopy images showed that LDH‐DS particles were partially intercalated and partially exfoliated, and well distributed in the PVC nanocomposites. The storage modulus below the glass transition region and the glass temperature of the PVC/LDH‐DS nanocomposites are greater than that of the pristine PVC. The mechanical properties of PVC/LDH‐DS nanocomposites indicate that LDH‐DS nanoparticles stiffen and toughen PVC. The tensile strength, Young's modulus, and Charpy notched impact strength of the PVC/LDH‐DS nanocomposites are greater than those of the pristine PVC and PVC/LDH‐DS composites prepared by the melt blending. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1471–1477, 2006
Electron beam synthesis and characterization of poly(vinyl alcohol)/montmorillonite nanocomposites
Authors: Abd Alla Safaa G. , Nizam El‐Din Horia M. , El‐Naggar Abdel Wahab M. 
Published: July 2006

AbstractPoly(vinyl alcohol) (PVA)/montmorillonite clay (MMT) nanocomposites in the form of films were prepared under the effect of electron beam irradiation. The PVA/MMT nanocomposites gels were characterized by X‐ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and mechanical measurements. The study showed that the appropriate dose of electron beam irradiation to achieve homogeneous nanocomposites films and highest gel formation was 20 kGy. The introduction of MMT (up to 4 wt %) results in improvement in tensile strength, elongation at break, and thermal stability of the PVA matrix. In addition, the intercalation of PVA with the MMT clay leads to an impressive improved water resistance, indicating that the clay is well dispersed within the polymer matrix. Meanwhile, it was proved that the intercalation has no effect on the metal uptake capability of PVA as determined by a method based on the color measurements. XRD patterns and SEM micrographs suggest the coexistence of exfoliated intercalated MMT layers over the studied MMT contents. The DSC thermograms showed clearly that the intercalation of PVA polymer with these levels of MMT has no influence on the melting transitions; however, the glass transition temperature (Tg) for PVA was completely disappeared, even at low levels of MMT clay. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1129–1138, 2006
Concentrated emulsion polymerization for preparation of β‐cyclodextrin‐supported chromatography columns
Authors: Baharvand H. , Zeynali M. E. , Rabiee A. 
Published: July 2006

AbstractConcentrated inverse emulsion polymerization was used for making chromatography columns (based on crosslinked polystyrene divinylbenzene (PS‐DVB)) with pore sizes less than 10 μm. According to DSC‐thermal gravimetry thermograms, it was confirmed that the residual monomer concentration after polymerization process is negligible. For application of these columns in chiral chromatography, the β‐cyclodextrin is chemically fixed on the PS‐DVB resin pore surface. The presence of hydroxyl groups in the PS‐DVB resin after chemical modification was confirmed by FTIR spectroscopy. By chemical modification of the PS‐DVB resin, thermal stability increased up to 446°C. The structure of columns was analyzed by scanning electron microscopy (SEM). SEM evaluations showed that the porous structure of PS‐DVB resin was maintained intact after the chemical modification with β‐cyclodextrin. According to X‐ray data, presence of the crystalline domain that is related to β‐cyclodextrin is confirmed.© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 857–863, 2006
Dehydration of tetrahydrofuran by pervaporation using crosslinked PVA/PEI blend membranes
Authors: Rao P. Srinivasa , Sridhar S. , Krishnaiah A. 
Published: July 2006

AbstractDense blend membranes were prepared by blending hydrophilic polymers poly(vinyl alcohol) (PVA) and poly(ethyleneimine) (PEI), which were then crosslinked by glutaraldehyde (GA) in a mixture of solvents under the catalysis of hydrochloric acid (HCl) for the dehydration of tetrahydrofuran (THF) by pervaporation. The effect of experimental parameters such as feed water concentration, permeate pressure, and membrane thicknesses on permeate parameters, i.e., flux and selectivity were determined with feed water concentration less than 40 wt %. The membranes were found to have good potential for breaking the azeotrope of 94 wt % THF with a flux of 1.072 and 0.376 kg/m2 h for plane PVA/PEI and crosslinked PVA/PEI blend membrane, which exhibited high selectivity of 156 and 579 respectively. Selectivity was found to improve with decreasing feed water concentration and increasing membrane thickness, whereas flux decreased correspondingly. High permeate pressure causes a reduction in both flux and selectivity. These effects were clearly elucidated with the aid of the known relationship among plasticization effect, degree of swelling, permeate pressure, and feed water concentration. These blend membranes were also subjected to sorption studies to evaluate the extent of interaction and degree of swelling in pure as well as binary feed mixtures. Further ion exchange capacity studies were carried out for all the crosslinked and uncrosslinked membranes to determine the total number of interacting groups present in the membranes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1152–1161, 2006
Soybean‐ and castor‐oil‐based thermosetting polymers: Mechanical properties
Authors: Can E. , Wool R. P. , Küsefoğlu S. 
Published: July 2006

AbstractMaleic anhydride modified soybean‐ and castor‐oil‐based monomers, prepared via the malination of the alcoholysis products of the oils with various polyols, such as pentaerythritol, glycerol, and bisphenol A propoxylate, were copolymerized with styrene to give hard rigid plastics. These triglyceride‐based polymers exhibited a wide range of properties depending on their chemical structure. They exhibited flexural moduli in the 0.8–2.5 GPa range, flexural strength in the 32–112 MPa range, glass transition temperatures (Tg) ranging from 72 to 152°C, and surface hardness values in the 77–90 D range. The polymers prepared from castor oil exhibited significantly improved modulus, strength, and Tg values when compared with soybean‐oil‐based polymers. These novel castor and soybean‐oil‐based polymers show comparable properties to those of the high‐performance unsaturated polyester (UP) resins and show promise as an alternative to replace these petroleum‐based materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1497–1504, 2006
Blending and white spirit permeation properties of the blends of modified polyamide and ethylene vinyl alcohol with varying vinyl alcohol contents
Authors: Yeh Jen‐Taut , Chen Heng‐Yi , Tsai Fang‐Chang 
Published: July 2006

AbstractThe blending and white spirit permeation properties of the MPAEVOH blends of modified polyamide (MPA) and ethylene vinyl alcohol copolymer (EVOH) were systematically investigated in this study. Three types of EVOHs with varying vinyl alcohol contents were used to prepare the MPAEVOH resins by melt blending them with the MPA resin, respectively. The peak melting temperatures and percentage crystallinity (Wc) values of the EVOH specimens increase significantly as their vinyl alcohol contents increase. The X‐ray diffraction patterns of the melt‐crystallized EVOH crystals transform from monoclinic to orthorhombic lattice as their vinyl alcohol contents are equal to or less than 56 wt %. After blending EVOH in MPA resins, the main melting endotherms and characteristic X‐ray diffraction patterns of both monoclinic and orthorhombic lattices of EVOH crystals originally present in MPAEVOH specimens almost disappear completely, when the weight ratios of MPA to EVOH are equal to or greater than 4. The free‐volume properties and white spirit permeation rates of the EVOH specimens reduce significantly as their vinyl alcohol contents increase. A noticeable “negative deviation” was found on the plots of white spirit permeation rates, annihilation intensity (I3), and/or fractional free‐volume (Fv) versus MPA contents as the MPA contents of each MPAEVOH sample series reach about 80 wt %. Possible reasons accounting for these interesting blending and barrier properties of MPAEVOH specimens are discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1224–1233, 2006
Investigation of free volume, interfacial, and toughening behavior for cyanate ester/bentonite nanocomposites by positron annihilation
Authors: Yu D. H. , Wang B. , Feng Y. , Fang Z. P. 
Published: July 2006

AbstractEffects of filler on microstructure and toughening behavior of cyanate ester (CE)/bentonite (BT) nanocomposites with different content of BT have been studied by positron annihilation lifetime spectroscopy, X‐ray diffraction, transmission electron microscopy, dynamic mechanical analysis, etc. The interesting results found by PALS indicate that the size and concentration of the free volume holes and the apparent free volume fraction increased with increasing the content of BT, which indicates that adding nano‐layers to thermosetting materials can lead to the high crosslinking density structure “looser.” The experimental results reveal that the increases in size of free volume holes and apparent free volume fraction are related to the increasing conversion of cure reaction. On the other hand, the mechanism of toughening (by adding the nano‐clay to the thermosetting material) has been discussed by combining free volume and interfacial property. It is shown that, for the high crosslinking thermosetting material‐based nanocomposites, both the property of free volume and dispersion state of nano‐layers are the two key factors in determining toughening property. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1509–1515, 2006
Preparation and characterization of cyclic polyesters from ring‐chain reactions of poly(oxyepichlorhydrin oxymaloyl)
Authors: Ferrahi Mohammed Issam , Belbachir Mohammed 
Published: July 2006

AbstractIn this article, the synthesis and characterization of cyclic polyesters of poly(oxyepichlorhydrin oxymaloyl) from a ring‐chain reaction induced by “Maghnite,” an acid‐exchanged montmorillonite as acid solid ecocatalyst (Mag‐H+), is described. Maghnite is already used as catalyst for polymerization of many vinylic and heterocyclic monomers [Belbachir, U.S. Pat. 066969.0101 (2001)]. The reactions were monitored by gel permeation chromatography and 1H‐NMR spectroscopy and the existence of cyclic species was proven. The effect of the amount of catalyst on yield and molecular weight of polymer was studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1240–1243, 2006
Preparation and physical properties of films prepared by crosslinking 1,9‐bis(glycidyloxypropyl)pentasiloxanes with α,ω‐bis(3‐aminopropyl)polydimethylsiloxane and their settlement and release properties
Authors: Lee Nam S. , Callow James A. , Callow Maureen E. , Finlay John A. , Weber William P. 
Published: July 2006

AbstractSix films were prepared by phenol‐catalyzed crosslinking of 1,9‐bis(glycidyloxypropyl)decamethylpentasiloxane (I) or 1,9‐bis[glycidyloxypropyl]‐3,5,7‐tris(3′,3′,3′‐trifluoropropyl)heptamethylpentasiloxane (II) with α,ω‐bis(3‐aminopropyl)‐PDMSs [Mn = 250 (a), 1700 (b), or 3200 (c)]. These films exhibited a wide range of glass transition temperatures (Tgs), high thermal stabilities, hydrophobicities, and fouling‐release properties. Thermal stabilities were measured by thermogravimetric analysis. Surface properties were evaluated by static and dynamic contact angle measurements. Mechanical properties and Tgs were determined by dynamic mechanical thermal analysis. The fouling‐release properties of films Ia–Ic and IIa–IIc toward spores and sporelings (young plants) of the green fouling macroalgae Ulva (syn. Enteromorpha) was also studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 751–757, 2006
Molecular weight distribution of polyethylene catalyzed by Ziegler–Natta catalyst supported on MgCl2 doped with AlCl3
Authors: Chen Yong‐Ping , Fan Zhi‐Qiang , Liao Jian‐He , Liao Shuang‐Quan 
Published: July 2006

AbstractTi‐based Ziegler–Natta catalysts supported on MgCl2 doped with AlCl3 were prepared by the reaction of MgCl2/AlCl3–ethanol adduct with TiCl4. No AlCl3 crystallites were found in the AlCl3‐doped catalysts by WAXD analysis, suggesting that AlCl3/MgCl2 solid solution was formed. The effect of doping on the catalyst performance in ethylene polymerization was investigated. The results showed that the catalysts based on AlCl3‐doped MgCl2 support exhibited a slightly higher activity than did the MgCl2‐supported catalyst and the molecular weight distribution (MWD) of polyethylene (PE) markedly increased (from 10.8 to 47.9) with the increase of AlCl3 content in catalysts. The changes in catalyst's active center distribution were studied based on nonlinear fitting of the polymer GPC curves by multiple Flory functions. It was found that increase of types of active centers by introducing AlCl3 into the support should be responsible for the broadening of MWD of PE. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1768–1772, 2006