bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal degradation of electron beam crosslinked polyethylene and (ethylene–vinylacetate) blends in hot water
Authors: Hassanpour S. , Khoylou F. , Jabbarzadeh E.
Published: June 2003

Low‐density polyethylene and (ethylene–vinylacetate) blends in pure form were exposed to electron beam radiation at doses between (80–150) kGy, at room temperature, in air. Postirradiation thermal aging was done through immersing the samples in hot water at 95°C. Mechanical properties and changes in chemical structure were determined after 1500 h. Accelerated oven aging test was carried out on thin films after immersing them in hot water for 1000 h. Heat aging treatment showed that the blends have a convenient thermal stability compared to polyethylene. Although elongation at break and tensile strength decreased after heat aging procedure, obviously, this reduction was lower in blended samples than that of pure PE. In all samples, hydroxyl and transvinylene unsaturated end groups were formed during heat aging in hot water. Formation of these groups was less in blends at doses between 80–100 kGy, but was higher at 150 kGy than pure polyethylene. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2346–2352, 2003
Thermal and thermomechanical properties of biocomposites made from modified recycled cellulose and recycled polypropylene
Authors: Espert Ana , Camacho Walker , Karlson Sigbritt
Published: June 2003

Residual cellulose fibers from the paper industry have been used as reinforcements in recycled polypropylene (PP) composites. The main obstacle to obtaining good properties with this biocomposite is deficiencies in the compatibility between the nonpolar matrices and the polar cellulose fibers used as reinforcements. The aim of this work was to improve the compatibilization between these cellulose fibers and the PP matrix with four different methods: modification by the addition of polypropylene–maleic anhydride copolymer (PPgMA) during the process of blending, preblending modification of the cellulose with a solution of PPgMA, modification of cellulose by silanes (vinyltrimethoxysilane), and acetylation of cellulose. Blends with all of the differently modified celluloses were prepared with the cellulose content varied up to 40%, and then all of the blends were subjected to thermal (differential scanning calorimetry and thermogravimetric analysis) and thermomechanical (dynamic mechanical thermal analysis) analyses. The results showed that the addition of cellulose fibers improved the thermomechanical behavior of the PP, increasing the value of the log of the dynamic modulus, and affected the thermal and thermooxidative behavior. Moreover, an advantage of the use of a recycled PP containing a small quantity of ethyl vinyl acetate (EVA) as a prime material in the composition was the enhancement of mechanical properties. The use of these methods for the modification of cellulose led to more desirable thermal and thermooxidative stabilities. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2353–2360, 2003
Graft copolymerizaztion of methyl acrylate onto chitosan initiated by potassium diperiodatocuprate (III)
Authors: Liu Yinghai , Liu Zhenghao , Zhang Yanzhe , Deng Kuilin
Published: June 2003

A novel redox system, potassium diperiodatocuprate [Cu (III)–chitosan], was employed to initiate the graft copolymerization of methyl acrylate (MA) onto chitosan in alkali aqueous solution. The effects of reaction variables such as monomer concentration, initiator concentration, pH and temperature were investigated. By means of a series of copolymerization reactions, the grafting conditions were optimized. Cu (III)–chitosan system was found to be an efficient redox initiator for this graft copolymerization. The structures and the thermal stability of chitosan and chitosan‐g‐poly(methyl acrylate) (PMA) were characterized by infrared spectroscopy (IR) and thermogravimetric analysis (TGA). In this article, a mechanism is proposed to explain the formation of radicals and the initiation. Finally, the graft copolymer was used as the compatibilizer in blends of poly(vinyl chloride) (PVC) and chitosan. The scanning electron microscope (SEM) photographs and differential scanning calorimetry (DSC) thermograms indicate that the graft copolymer improved the compatibility of the blend. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2283–2289, 2003
Synthesis and characterization of methyl methacrylate/styrene hyperbranched copolymers via living radical mechanism
Authors: Ishizu Koji , Park Jaebum , Ohta Yoshihiro , Shibuya Takeshi
Published: June 2003

Free‐radical copolymerizations of N,N‐diethylaminodithiocarbamoylmethylstyrene (inimer: DTCS) with a methyl methacrylate (MMA)/zinc chloride (ZnCl2) complex were carried out under UV light irradiation. DTCS monomers play an important role in this copolymerization system as an inimer that is capable of initiating living radical polymerization of the vinyl group. The reactivity ratios (r1 = 0.56 and r2 = 0.52: DTCS [M1]; MMA [M2]) obtained for this copolymerization system were different from a corresponding model system (alternating copolymer) of a styrene and MMA/ZnCl2 complex (r1 = 0.25 and r2 = 0.056). It was found that the hyperbranched copolymers produced exhibited a random branching structure. It was found that the Lewis acid ZnCl2 formed the complex not only with MMA but also with the carbamate group of inimer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2490–2495, 2003
Study on thermoplastic polyurethane/polypropylene (TPU/PP) blend as a blood bag material
Authors: Ajili Shadi H. , Ebrahimi Nadereh G. , Khorasani Mohammad T.
Published: June 2003

Blends with different ratios of thermoplastic polyurethane/polypropylene (TPU/PP) were prepared by melt mixing using an internal Haake mixer. Properties of the blends were investigated using SEM micrographs of cryofractures and measurement of the mechanical strength, water absorption, cell culture, and platelet adhesion in vitro tests, which were compared with those of PVC blood bags. The effect of the addition of the ethylene–vinyl acetate (EVA) copolymer on the TPU/PP blend properties was investigated. The results indicated that a TPU/PP/EVA = 80/20/5 blend can be used as a new blood bag material. It was observed that the blend is homogeneous with higher mechanical strength than that of the commercial PVC blood bag. This blend also showed a compatible cell response in contact with L929 fibroblast cells and fewer tendencies to interaction with platelets compared to the PVC blood bag. Although the blends were immissible and no chemical reaction at the interface could be found, the blood compatibility of the blends were improved. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2496–2501, 2003
Viscosity behavior and surface and interfacial activities of hydrophobically modified water‐soluble acrylamide/N‐phenyl acrylamide block copolymers
Authors: Abu‐Sharkh B. F. , Yahaya G. O. , Ali S. A. , Hamad E. Z. , Abu‐Reesh I. M.
Published: June 2003

In this study, the viscosity behavior and surface and interfacial activities of associative water‐soluble polymers, which were prepared by an aqueous micellar copolymerization technique from acrylamide and small amounts of N‐phenyl acrylamide (1.5 and 5 mol %), were investigated under various conditions, including the polymer concentration, shear rate, temperature, and salinity. The copolymer solutions exhibited increased viscosity due to intermolecular hydrophobic associations, as the solution viscosity of the copolymers increased sharply with increasing polymer concentration, especially above a critical overlap concentration. An almost shear‐rate‐independent viscosity (Newtonian plateau) was also displayed at high shear rates, and typical non‐Newtonian shear‐thinning behavior was exhibited at low shear rates and high temperatures. Furthermore, the copolymers exhibited high air–water and oil–water interfacial activities, as the surface and interfacial tensions decreased with increasing polymer concentration and salinity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2290–2300, 2003
Pervaporation membranes based on imide‐containing poly(amic acid) and poly(phenylene oxide)
Authors: Polotskaya G. A. , Kuznetsov Y. P. , Goikhman M. Y. , Podeshvo I. V. , Maricheva T. A. , Kudryavtsev V. V.
Published: June 2003

Three imide‐containing poly(amic acids) were synthesized and used for homogeneous and composite membrane preparation. The transport properties of composite membranes consisting of an imide‐containing poly(amic acid) top layer on an asymmetric porous poly(phenylene oxide) support were studied in the pervaporation of aqueous solutions of organic liquids (ethanol, isopropanol, acetone, and ethylacetate) and organic/organic mixtures (ethylacetate/ethanol, methanol/cyclohexane). For most of the aqueous/organic mixtures, the composite membranes exhibited dehydration properties. Dilute aqueous solutions of ethylacetate were an exception. In these solutions, the composite membranes exhibited organophilic properties, high permeability, and selectivity with respect to ethylacetate. In the pervaporation of methanol/cyclohexane mixtures, methanol was removed with very high selectivity. To account for specific features of pervaporation on the composite membranes, the sorption and transport properties of homogeneous membranes prepared from polymers comprising the composite membrane [imide‐containing poly(amic acids) and poly(phenylene oxide)] were studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2361–2368, 2003
Effects of maleated syndiotactic polystyrene on the morphology, mechanical properties, and crystallization behavior of syndiotactic polystyrene/polyamide 6 blends
Authors: Quan Zhang Xue , Son Younggon
Published: June 2003

The compatibilization of syndiotactic polystyrene (sPS)/polyamide 6 (PA‐6) blends with maleic anhydride grafted syndiotactic polystyrene (sPS‐g‐MA) as a reactive compatibilizer was investigated. The sPS/PA‐6 blends were in situ compatibilized by a reaction between the maleic anhydride (MA) of sPS‐g‐MA and the amine end group of PA‐6. The occurrence of the chemical reaction was substantiated by the disappearance of a characteristic MA peak from the Fourier transform infrared spectrum. Morphology observations showed that the size of the dispersed PA‐6 domains was significantly reduced and that the interfacial adhesion was much improved by the addition of sPS‐g‐MA. As a result of reactive compatibilization, the impact strengths of the sPS/PA‐6 blends increased with an increase in the sPS‐g‐MA content. The crystallization behaviors of the blends were affected by the compatibilization effect of sPS‐g‐MA. A single melting peak of sPS in the noncompatibilized blend was gradually split into two peaks as the amount of the compatibilizer increased. A single crystallization peak of PA‐6 in the noncompatibilized blend became two peaks with the addition of 3 wt % sPS‐g‐MA. The new peak was a result of the fractionation crystallization. As the amount of sPS‐g‐MA increased, the intensity of the new peak increased, and the original peak nearly disappeared. Finally, the crystallization peak of PA‐6 disappeared with 20 wt % sPS‐g‐MA in the blend. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2502–2506, 2003
Ionic conduction of polyurethane/sulfonated polyether blends
Authors: Wang Xinling , Zhu Weihua , Liu Yunhang , Tang Xiaozhen , Yang Xiaohui
Published: June 2003

Sodium single‐ion poly(ether urethane)/sulfonated polyether blends based on the synthesis of a series of poly(ethylene oxide)s with sodium sulfonate side chains (SPEO) with different molecular weights were prepared and characterized by Fourier transform infrared spectroscopy, elemental analysis, Fourier transform Raman spectroscopy, differential scanning calorimetry, and complex impedance analysis. The results showed that the molecular weight and content of SPEO significantly influenced the compatibility between the hard and soft segments of polyurethane (PU), the glass‐transition temperature, and the ionic conductivities of PU/SPEO complexes. The glass‐transition temperature of the system obviously decreased and the ionic conductivities of PU/SPEO complexes progressively increased with an increase in the SPEO content. In a certain range of temperatures, the ionic conductivities of PU/SPEO complexes agreed with an Arrhenius equation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2369–2373, 2003
Use of new diimide‐dinaphthols in preparation of novel thermally stable poly(ester‐imide)s
Authors: Mehdipour‐Ataei S. , Keshavarz S.
Published: June 2003

Reaction of 5‐amino‐1‐naphthol with pyromellitic dianhydride (PMDA), benzophenonetetracarboxylic dianhydride (BTDA), and hexafluoroisopropylidene diphthalic anhydride (6FDA) afforded aromatic diols with preformed imide structure. High temperature solution polycondensation reactions of the obtained diimide‐dinaphthols with aromatic and aliphatic diacid chlorides resulted in the preparation of nine different poly(ester‐imide)s. These were fully characterized, and the physical and thermal properties of the obtained polymer were studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2567–2572, 2003
Graft copolymerization of nitrogen‐ and phosphorus‐containing monomers onto cellulosics for flame‐retardant finishing of cotton textiles
Authors: Abdel‐Mohdy F. A.
Published: June 2003

Phosphoramide containing an active vinyl group (P‐III) was prepared. Its structure was confirmed by elemental analysis and Fourier transform infrared, nuclear magnetic resonance, and mass spectroscopy. P‐III was evaluated as a fire‐retardant finishing agent for cotton fabrics. It was applied to cotton fabrics using a graft process with an Fe2+/H2O2 redox system. The major factors affecting the reaction were studied. The finished cotton fabrics were examined for flammability, and the effect of washing on treated fabrics was also examined. The results showed that P‐III can be successfully used as a flame retardant for cotton fabrics. Durably flame‐retardant cotton fabrics were obtained at add‐on levels higher than 38%. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2573–2578, 2003
Thermooptical properties of poly(methyl methacrylate)‐based azobenzene composites
Authors: Wu Shuizhu , Zeng Fang , Wang Hai , She Weilong , Cai Zhigang
Published: June 2003

In this article, poly(methyl methacrylate)‐based azobenzene composites were prepared. The temperature coefficient of the refractive index of these composites was investigated. The dependence of the temperature coefficient of the refractive index on the azobenzene chromophore concentrations was studied experimentally. These optically interesting thermal parameters are very useful in material optical applications, thermooptical polymeric switches, and waveguide technology. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2374–2377, 2003
Fractal analysis of thermooxidative degradation process of polymeric melts
Authors: Kozlov G. V. , Shustov G. B. , Zaikov G. E.
Published: June 2003

The fractal dimension of a macromolecular coil is used for the characterization of a polymeric melt structure. It is shown that the kinetics of oxygen consumption is defined by both the chemical constitution of a polymer and its structure. The quantitative analysis of the kinetical curves of the oxygen consumption in the thermooxidative degradation process was carried out in the framework of the fractal approach. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2378–2381, 2003
Fractal analysis of polymer molecular weight distribution: Dynamic scaling
Authors: Kozlov G. V. , Malkanduev Yu. A. , Zaikov G. E.
Published: June 2003

The correctness of the molecular weight distribution (MWD) of a poly(dimethyl diallyl ammonium chloride) type was shown in the frame‐work of the dynamic distribution function of the irreversible aggregation cluster–cluster model. The buildup of a generalized distribution curve confirms the possibility to describe the polymerization processes within the framework of the mentioned model and allows one to predict the kinetics of MWD changes as the function of the initial monomer concentration c0 and reaction time t. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2382–2384, 2003
Gel point determination for the copolymerization system of cardanyl acrylate and styrene and its critical conversion
Authors: Nguyen Le Huong , Koerner Hilmar , Lederer Klaus
Published: June 2003

The copolymerization of cardanyl acrylate (CA) and styrene (S) with methyl ethyl ketone peroxide (MEKP) and cobalt salt as the initiator was studied by means of rheometry and isothermal DSC. The gel point of the CA‐S reaction system was determined by rheological measurements at 50 and 70°C. In addition, rheological measurements provide very useful information on the evolution of the physical properties of the system during curing, such as viscosity and shear modulus. We demonstrate that isothermal DSC experiments, using the Avrami model, can be used to obtain a more detailed description of the curing process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2385–2390, 2003
Tire rubber–sisal composites: Effect of mercerization and acetylation on reinforcement
Authors: Martins Maria Alice , Joekes Ines
Published: June 2003

Tire rubber particles were mixed randomly with short sisal fibers and hot pressed. Sisal fibers were used as received, mercerized, and mercerized/acetylated. The fibers were characterized by scanning electron microscopy (SEM), thermal gravimetry analysis (TGA), infrared spectroscopy (FTIR), water sorption, and mechanical properties. Thermal stability of the mercerized/acetylated fibers improves (from 200 to 300°C) with respect to the raw fibers, and water sorption is ∼ 20% smaller than for the raw and the mercerized fibers. Tensile strength is unchanged after the chemical treatments. Water sorption, mechanical properties, and SEM evaluated the performance of the tire rubber composites. All composites showed enhanced elastic modulus; increase is dependent on fiber load. Smallest water sorption was obtained in composites with the mercerized/acetylated fibers. With these fibers at 10% load, the best results were obtained with the smaller tire rubber particles (320 μm) and at 5% load with the bigger (740 μm) tire rubber particles. Both composites showed ∼ 50% increase in tensile strength when compared to similar composites with raw fibers. SEM of the surface of fracture showed that the adhesion between fiber and rubber was enhanced after both chemical treatments. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2507–2515, 2003
Polyurethane–polyaniline conducting graft copolymer with improved mechanical properties
Authors: Abbati G. , Carone E. , D'Ilario L. , Martinelli A.
Published: June 2003

The crosslinking effects on the mechanical and electrical properties of a conducting copolymer obtained by grafting polyaniline on a carboxylated polyurethane were investigated. The synthesis and characterization of the polyurethane–polyaniline copolymer (PEUAPAN) were previously reported. The crosslinking process was carried out by reacting ethylenediamine with those polyurethane residual carboxylic groups not involved in the amide binding to the conducting chains. The insoluble material obtained (PEUAPANc) shows a marked elastomeric feature, as evidenced in stress–strain and stress–relaxation measurements. Although the crosslinked graft copolymer conductivity is lower than that of the pristine material, its variation during deformation cycles is reversible because the chain relaxation and viscous flow phenomena are drastically suppressed by the crosslinks. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2516–2521, 2003
A new postfunctional method to synthesize C60‐containing polysiloxanes
Authors: Li Zhen , Qin Jingui
Published: June 2003

Two new C60‐containing polysiloxanes were synthesized by a new postfunctional method. First, the predesigned amimo end‐functionalized polysiloxane was prepared, and then the reactive macromolecular intermediate reacted with C60 molecules in chlorobenzene to yield the C60‐containing polysiloxanes. Molecular structural characterization for the polymers was presented by 1H‐NMR, IR, and ultraviolet‐visible spectra. The polymers exhibited good solubility in common organic solvents and were air stable. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2068–2071, 2003
Synthesis of poly(acrylamide‐co‐4‐vinylpyridine) hydrogels and their application in heavy metal removal
Authors: El‐Hamshary Hany , El‐Garawany Mohamed , Assubaie Fahad N. , Al‐Eed Mohamed
Published: June 2003

A series of poly(acrylamide‐co‐4‐vinylpyridine) hydrogels having varied acrylamide/4‐vinylpyridine content and different crosslink ratios of N,N′‐methylene‐bisacrylamide was prepared by using solution polymerization. The prepared hydrogel polymers were characterized by their elemental analysis, infrared spectroscopy, and equilibrium water content. The polymers were investigated toward metal ion uptake of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II). The polymers were more sensitive to Cu(II) and Ni(II) and the order of metal ion binding was Ni(II), Cu(II) > Zn(II) > Co(II) > Mn(II). Metal ion uptake by the polymers was reduced as the pH of the medium decreased. Recycling of the resins resulted in high recovery of the metal ions from their aqueous solutions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2522–2526, 2003
Thermal and flammability properties of a silica–poly(methylmethacrylate) nanocomposite
Authors: Kashiwagi Takashi , Morgan Alexander B. , Antonucci Joseph M. , VanLandingham Mark R. , Harris Richard H. , Awad Walid H. , Shields John R.
Published: June 2003

PMMA, poly(metheylmethacrylate), nanocomposites were made by in situ radical polymerization of MMA, methylmethacrylate, with colloidal silica (ca. 12 nm) to study the effects of nanoscale silica particles on the physical properties and flammability properties of PMMA. Transparent samples resulted and the dispersity of the particles was examined by transmission electron microscopy and atomic force microscopy. The addition of nanosilica particles (13% by mass) did not significantly change the thermal stability, but it made a small improvement in modulus, and it reduced the peak heat release rate roughly 50%. Last, the flame‐retardant mechanism provided by the addition of nanosilica particles in PMMA is discussed. Published 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2072–2078, 2003
Effects of nanofiber treatments on the properties of vapor‐grown carbon fiber reinforced polymer composites
Authors: Cortés P. , Lozano K. , Barrera E. V. , Bonilla‐Rios J.
Published: June 2003

Vapor‐grown carbon fibers (VGCFs) were exposed to a series of chemical treatments and to electrochemical deposition of copper to modify their surface conditions and alter their electrical properties. The fibers were then mixed with polypropylene using a Banbury‐type mixer obtaining composites up to 5 wt % VGCFs. Rheological, electrical, and mechanical properties were evaluated and compared to unfilled polypropylene processed in a similar manner. The composites made with HNO3‐treated VGCFs showed a lower electrical resistivity compared to the untreated samples. The composites containing VGCFs subjected to the copper electrodeposition process showed the lowest resistivity with no change in the mechanical properties. Changes in rheological properties demonstrated the effects of varying surface conditions of the VGCFs. Microscopic analysis of these composites showed a heterogeneous distribution of VGCFs forming an interconnected network with the presence of copper on the surface of the VGCFs and in the matrix. Both the interconnected network and the presence of copper led to a lower percolation threshold than those seen in a previous work where high dispersion was sought. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2527–2534, 2003
Structural development of HDPE in injection molding
Authors: Sousa R. A. , Reis R. L. , Cunha A. M. , Bevis M. J.
Published: June 2003

This study investigated some relevant structure/properties relationships in shear‐controlled orientation in injection molding (SCORIM) of high‐density polyethylene (HDPE). SCORIM was used to deliberately induce a strong anisotropic character in the HDPE microstructure. Three grades with different molecular weight characteristics were molded into tensile test bars, which were subsequently characterized in terms of the mechanical behavior by tensile tests and microhardness measurements. The structure developed upon processing was also characterized by polarized light microscopy (PLM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and wide‐angle X‐ray diffraction (WAXD). SCORIM allows the production of very stiff molded parts, exhibiting a very well‐defined laminated morphology. This morphology is associated with both an M‐shaped microhardness profile and a pronounced mechanical anisotropy. These characteristics are supported by an analogous variation in the crystallinity and a high level of molecular orientation, as indicated, respectively, by calorimetric measurements and X‐ray diffraction results. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2079–2087, 2003
Electrochemical behavior of an interpenetrating polymer network hydrogel composed of poly(propylene glycol) and poly(acrylic acid)
Authors: Kim Seon Jeong , Lee Ki Jung , Kim Sun I. , Lee Young Moo , Chung Tack Dong , Lee Sang Hoon
Published: June 2003

An interpenetrating polymer network (IPN) hydrogel based on poly(propylene glycol) and poly(acrylic acid) was prepared by UV irradiation. The swelling behavior of the IPN hydrogel was studied by the immersion of the gel in aqueous NaCl solutions of various concentrations. The swelling ratio decreased with an increase in the NaCl concentration. The electrically sensitive behavior of the IPN hydrogel in electric fields was also investigated. The IPN hydrogel also showed a stepwise bending behavior that depended on the electric stimulus. The bending angle and bending speed of the IPN hydrogel were greatest in 0.6 wt % aqueous NaCl and increased with an increase in the applied voltage. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2301–2305, 2003
Determination of the competitive adsorption of heavy metal ions on poly(n‐vinyl‐2‐pyrrolidone/acrylic acid) hydrogels by differential pulse polarography
Authors: Çaykara Tuncer , İnam Recai
Published: June 2003

Poly(N‐vinyl‐2‐pyrrolidone) and poly(N‐vinyl‐2‐pyrrolidone/acrylic acid) hydrogels were prepared by gamma irradiation for the removal of heavy metal ions (i.e., lead, copper, zinc, and cadmium) from aqueous solutions containing different amounts of these ions (2.5–10 mg/L) and at different pH values (1–13). The observed affinity order in adsorption of these metal ions on the hydrogels was Zn(II) > Pb(II) > Cu(II) > Cd(II) under competitive conditions. The optimal pH range for the heavy metal ions was from 7 to 9. The adsorption of the heavy metal ions decreased with increasing temperature in both water and synthetic seawater conditions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2013–2018, 2003
Polarographic determination of the competitive adsorption of U(VI), Pb(II), and Cd(II) ions on poly(N‐vinyl‐2‐pyrrolidone‐g‐citric acid) hydrogels
Authors: İnam Recai , Çaykara Tuncer , Alan Şerife Şirin
Published: June 2003

Poly(N‐vinyl‐2‐pyrrolidone‐g‐citric acid) [P(VP‐g‐CA)] hydrogels were prepared for the removal of U(VI), Pb(II), and Cd(II) from aqueous solutions containing different amounts of these ions (2.5–10 mg/L). Different pHs (1–13), temperatures (20–40°C), and ionic strengths (0.5M) were also tried for the adsorption behavior of these ions. The competitive adsorption values of U(VI), Pb(II), and Cd(II) ions on pure poly(N‐vinyl‐2‐pyrrolidone) were low [0.71–2.03 mg of U(VI)/g of dry gel, 0.15–1.58 mg of Pb(II)/g of dry gel, and 0.10–0.68 mg of Cd(II)/g of dry gel]. The incorporation of citric acid significantly increased the adsorption of these ions [0.67–2.12 mg of U(VI)/g of dry gel, 0.44–1.88 mg of Pb(II)/g of dry gel, and 0.04–0.92 mg of Cd(II)/g of dry gel for P(VP‐g‐CA)‐1; 0.71–2.36 mg of U(VI)/g of dry gel, 0.60–2.16 mg of Pb(II)/g of dry gel, and 0.14–0.80 mg of Cd(II)/g of dry gel for P(VP‐g‐CA)‐2; and 0.79–2.47 mg of U(VI)/g of dry gel, 0.70–2.30 mg of Pb(II)/g of dry gel, and 0.20–0.86 mg of Cd(II)/g of dry gel for P(VP‐g‐CA)‐3]. The observed affinity order of adsorption was U(VI) > Pb(II) > Cd(II) for competitive conditions. The optimal pH range for the removal of these ions was 5–9. Competitive adsorption studies showed that other stimuli, such as the temperature and ionic strength of the solution, also influenced the U(VI), Pb(II), and Cd(II) adsorption capacity of P(VP‐g‐CA) hydrogels. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2019–2024, 2003
Preparation of high‐molecular‐weight poly(N‐vinylcarbazole) by the photoinduced low‐temperature solution polymerization of N‐vinylcarbazole in 1,1,2,2‐tetrachloroethane
Authors: Lee Joon‐Seok , Seok Lyoo Won , Kyun Noh Seok , Ho Kim Joon , Won Lee Jin , Do Ghim Han , Youl Lee Ji
Published: June 2003

For the preparation of high‐molecular‐weight (HMW) poly(N‐vinylcarbazole) (PVCZ) with a narrow molecular weight distribution, N‐vinylcarbazole (VCZ) was solution‐polymerized in 1,1,2,2‐tetrachloroethane (TCE) at −20, 0, and 20°C with photoinitiation. The effects of the polymerization temperature and the concentrations of the polymerization solvent and photoinitiator on the polymerization behavior and molecular parameters of PVCZ were investigated. A low polymerization temperature with photoirradiation was successful in obtaining HMW PVCZ with a smaller temperature rise during polymerization than that for thermal free‐radical polymerization by azobisisobutyronitrile (AIBN). The photo‐solution‐polymerization rate of VCZ in TCE was proportional to [AIBN]0.45. The molecular weight was higher and the molecular weight distribution was narrower for PVCZ made at lower temperatures. For PVCZ prepared in TCE at −20°C with a photoinitiator concentration of 0.00003 mol/mol of VCZ, a weight‐average molecular weight of 920,000 was obtained, with a polydispersity index of 1.46, and the degree of transparency converged to about 99%. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2391–2396, 2003
Phase behavior of hydrogen‐bonded ternary polymer blends
Authors: Hsu Wen‐Ping
Published: June 2003

Although poly(ethyl methacrylate) (PEMA) and poly(methyl methacrylate) (PMMA) are only slightly different in structure, they are known to be immiscible. Polystyrene is not miscible with PEMA or PMMA. However, when polystyrene is modified to contain certain vinyl phenol groups to become poly(styrene‐co‐vinyl phenol) (PSVPh), it can be miscible with both PEMA and PMMA. What is the miscibility of a ternary blend consisting of PEMA, PMMA, and PSVPh? For this question to be answered, binary blends of PEMA (or PMMA) were first made with PSVPh. Their miscibility was examined. Then, ternary blends composed of PEMA, PMMA, and PSVPh were prepared and measured calorimetrically. The role of PSVPh between PEMA and PMMA and the effect of different contents of vinyl phenol groups on the miscibility of the ternary blends were investigated. On the basis of experimental results, increasing the vinyl phenol contents of PSVPh seemed to have an adverse effect on the miscibility of the ternary blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2088–2094, 2003
Fourier transform near‐infrared and electron spin resonance studies on the crosslinking reaction of liquid carboxylated poly(acrylonitrile‐co‐butadiene) rubber with dicumyl peroxide in dioxane
Authors: Masaki Kohji , Ohkawara Shin‐Ichi , Hirano Tomohiro , Seno Makiko , Sato Tsuneyuki
Published: June 2003

The crosslinking reaction of liquid carboxylated poly(acrylonitrile‐co‐butadiene) [or nitrile rubber (NBR); acrylonitrile = 10 wt %] with dicumyl peroxide (DCPO) was studied in dioxane by means of Fourier transform near‐infrared spectroscopy (FT‐NIR) and electron spin resonance spectroscopy (ESR). Among the three butadiene units (1,2, cis‐1,4, and trans‐1,4 units) of NBR, only the pendant vinyl group of the 1,2 unit showed an absorption at 6110 cm−1 from the FT‐NIR examination of dioxane solutions of NBR, 1‐octene, 3,3‐dimethyl‐1‐butene, trans‐2‐octene, cis‐5‐octen‐1‐ol, poly‐cis‐1,4‐butadiene, and poly‐1,2‐butadiene. The crosslinking reaction was followed in situ in dioxane by the monitoring of the disappearance of the pendant vinyl double bond with FT‐NIR. The initial disappearance rate (R0) of the vinyl group was expressed by R0 = k[DCPO]0.9[NBR]−0.2 (120°C). The overall activation energy of the reaction was calculated to be 20.7 kcal/mol. This unusual rate equation suggests unimolecular termination due to degradative chain transfer and depressed reactivity of the vinyl group caused by crosslinking. ESR study of the reaction mixture revealed that an allyl‐type polymer radical was formed in the reaction, and its concentration increased with time and was then saturated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2095–2101, 2003
Mechanical and thermal properties of high‐density polyethylene toughened with glass beads
Authors: Yuan Qiang , Jiang Wei , An Lijia , Li R. K. Y. , Jiang Zhenhua
Published: June 2003

Glass beads were used to improve the mechanical and thermal properties of high‐density polyethylene (HDPE). HDPE/glass‐bead blends were prepared in a Brabender‐like apparatus, and this was followed by press molding. Static tensile measurements showed that the modulus of the HDPE/glass‐bead blends increased considerably with increasing glass‐bead content, whereas the yield stress remained roughly unchanged at first and then decreased slowly with increasing glass‐bead content. Izod impact tests at room temperature revealed that the impact strength changed very slowly with increasing glass‐bead content up to a critical value; thereafter, it increased sharply with increasing glass‐bead content. That is, the Izod impact strength of the blends underwent a sharp transition with increasing glass‐bead content. It was calculated that the critical interparticle distance for the HDPE/glass‐bead blends at room temperature (25°C) was 2.5 μm. Scanning electron microscopy observations indicated that the high impact strength of the HDPE/glass‐bead blends resulted from the deformation of the HDPE matrix. Dynamic mechanical analyses and thermogravimetric measurements implied that the heat resistance and heat stability of the blends tended to increase considerably with increasing glass‐bead content. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2102–2107, 2003
Physicochemical properties of irradiated and loaded LDPE films with polyfunctional monomers
Authors: Ali Z. I. , Youssef H. A. , Saleh H. H. , Zahran A. H.
Published: June 2003

Polyfunctional monomers (PFMs), namely, trimethylol propane trimethacrylate (TMPTMA), trimethylol propane triacrylate, ethylene glycol dimethacrylate, and diethylene glycol diacrylate were blended with low‐density polyethylene (LDPE) and exposed to different doses of EB irradiation. Fourier transform infrared and ultraviolet and UV–vis spectroscopy of the unirradiated, irradiated, unloaded, and PFMs‐loaded LDPE films were studied under various irradiation doses up to 300 kGy. The degree of crosslinking and oxidative degradation, as measured by the spectroscopic parameters, were dependent on both the irradiation dose and the type of loaded PFMs. For all of the loaded monomers, the extent of crosslinking increased at different rates as a function of irradiation dose. TMPTMA monomer was the most efficient in enhancing the crosslinking of LDPE films compared to the other loaded monomers. However, the unloaded LDPE film showed the least extent of crosslinking. In addition, the EB‐radiation‐induced changes, such as trans‐vinylene formation, a decrease in vinyl and vinylidene unsaturation; and carbonyl double‐bond formation and change in crystallinity were correlated. The importance of these results on the prediction of the role of polyfunctional monomers in the production of crosslinked polymers is discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2025–2035, 2003
Polymorphism in intercalated poly(vinylidene fluoride)/clay nanocomposites
Authors: Priya L. , Jog J. P.
Published: June 2003

Polymorphism in poly(vinylidene fluoride) (PVDF)/clay nanocomposites was studied. Poly(vinylidene fluoride)/clay nanocomposites were prepared with melt intercalation. The samples were characterized with X‐ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The nanocomposite exhibited the β form. Thermal annealing performed at 125 and 185°C showed that the β form of PVDF was stable. The stability of the β form of PVDF was ascertained from these studies. The β form of PVDF in the nanocomposites could be due to crystallization in the constrained phase. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2036–2040, 2003
Poly(sulfobetaine)s and corresponding cationic polymers. XI. Synthesis and aqueous solution properties of a cationic poly(methyl iodide quaternized ethyl vinyl ether/N,N‐dimethylaminopropyl maleamidic acid) copolymer
Authors: Lee Wen‐Fu , Chen Yan‐Ming
Published: June 2003

A copolymer prepared by the copolymerization of ethyl vinyl ether and maleic anhydride underwent amidoacidation with N,N‐dimethylaminopropylamine. The obtained ethyl vinyl ether/dimethylaminopropyl maleamidic acid copolymer was then reacted with methyl iodide to yield poly(methyl iodide quaternized ethyl vinyl ether/N,N′‐dimethylaminopropyl maleamidic acid) (MIQEDMAPMA). The greatest difference from other polyelectrolytes was the carboxylic group on the polymer chain unit of MIQEDMAPMA. Its aqueous solution properties in various salts and at various pH values were studied by measurements of the reduced viscosity and intrinsic viscosity. The reduced viscosity and intrinsic viscosity of this cationic polyelectrolyte were related to the types and concentrations of the added salts. The tendency of the salt effect was similar to that of other polyelectrolytes; that is, soft salt anions were more easily bound to the quaternary ammonium (R4N+) of MIQEDMAPMA than hard salt anions. Some salt ions strongly attracted the quaternary ammonium of the cationic polymeric side chain for the agglomeration of the polymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2261–2269, 2003
Highly efficient flocculant synthesized through the dispersion copolymerization of water‐soluble monomers induced by γ‐ray irradiation: Synthesis and polymerization kinetics
Authors: Ye Qiang , Zhang Zhicheng , Ge Xuewu
Published: June 2003

A water‐soluble cationic copolymer dispersion was prepared by the polymerization of the cationic monomer (2‐methacryloyloxyethyl)trimethyl ammonium chloride and acrylamide initiated with60Co γ‐rays. The polymerization was carried out in a salt solution that did not dissolve the resulting copolymer and in the presence of a polymeric dispersant that was soluble in the salt solution. The polymerization conversion was studied gravimetrically. The bulk viscosity of the copolymer dispersion was determined with a rotation viscometer. The intrinsic viscosity of the copolymer was measured viscometrically, and the particle size was determined with an optical microscope. The influence of some conditions on the copolymerization was studied, including the irradiation dose, dose rate, concentrations and compositions of the monomers, dispersant content, and types and contents of the inorganic salts. The flocculating characteristics of a synthetic cationic copolymer dispersion were also briefly investigated. The optimal conditions for polymerization were summarized, and some aspects of the polymerization mechanisms were examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2108–2115, 2003
Physical properties of polyethylene/silicate nanocomposite blown films
Authors: Hyun Ki , Chong Wang , Koo Min , Chung In Jae
Published: June 2003

Maleated polyethylene/silicate nanocomposite and maleated polyethylene/SiO2 blown films were prepared by melt extrusion. The silicate and SiO2 significantly affected the physical properties of the films. The former films showed higher tensile strength than the latter films. This high reinforcement effect seemed to be attributable to the strong interaction between the matrix and silicate as well as the uniform dispersion of silicate layers in the polymer matrix. The addition of silicate beyond a certain content gave a worse Elmendorf tear strength than SiO2. The silicate did not increase the falling dart impact strength at all. The worst Elmendorf strength apparently originated from the orientation of anisotropic silicate rather than the orientation of lamellae of the polymer matrix, and the silicate made the films more brittle. The well‐dispersed silicate layers in the polymer matrix gave almost the same optical properties as the pure polymer despite the increase in the silicate content. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2131–2136, 2003
Crystallization behavior, mechanical properties, and environmental biodegradability of poly(β‐hydroxybutyrate)/cellulose acetate butyrate blends
Authors: Wang Tiezhu , Cheng Guoxiang , Ma Shihu , Cai Zhijiang , Zhang Liguang
Published: June 2003

The miscibility, crystallization behavior, tensile properties, and environmental biodegradability of poly(β‐hydroxybutyrate) (PHB)/cellulose acetate butyrate (CAB) blends were studied with differential scanning calorimetry, scanning electron microscopy, wide‐angle X‐ray diffraction, and polarizing optical microscopy. The results indicated that PHB and CAB were miscible in the melt state. With an increase in the CAB content, the degree of crystallinity and melting temperature of the PHB phase decreased, and this broadened the narrow processability window of PHB. As the elongation at break increased from 2.2 to 7.3%, the toughness and ductility of PHB improved. From the degradation test, it could be concluded that degradation occurred gradually from the surface to the inside and that the degradation rate could be adjusted by the addition of the CAB content. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2116–2122, 2003
Effects of rosin‐type cocrystal nucleating agents on the crystallization process and the properties of polypropylene
Authors: Wang Hui , Li Chun‐Cheng , Zhang Dong , Li Zhen‐Yi
Published: June 2003

A new kind of rosin‐type nucleating agent for polypropylene (PP), the cocrystal of dehydroabietic acid, potassium dehydroabietate, and sodium dehydroabietate, was prepared, and the effects of the nucleating agents on the mechanical and crystallization properties of PP were also studied. The results of differential scanning calorimetry and X‐ray diffraction proved that the cocrystal of dehydroabietic acid and compound alkali dehydroabietate was formed rather than a simple blend of dehydroabietic acid and single alkali dehydroabietate. When it was added to PP, the size of the PP spherulite decreased; the mechanical properties, crystallization temperature, and transparency of PP were substantially improved. Thus, the cocrystal of dehydroabietic acid, potassium dehydroabietate, and sodium dehydroabietate acted as a more effective nucleating agent for PP. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2137–2141, 2003
Thermal and morphological studies of chemically prepared emeraldine‐base‐form polyaniline powder
Authors: Chen Cheng‐Ho
Published: June 2003

In this study, emeraldine base (EB)‐form polyaniline (PANI) powder was chemically prepared in 1M HNO3 aqueous solution. The thermal characteristics and chemical structures of this powder were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD). A polarizing optical microscope was also used to examine the crystalline morphology of this sample. The results indicated that the EB‐form PANI powder had a discernible moisture content. Moreover, in the first run of DSC thermal analysis, the exothermic peak at 170–340°C was due to the crosslinking reaction occurring among the EB‐form PANI molecular chains. FTIR and XRD examinations further confirmed the chemical crosslinking reaction during thermal treatment. TGA results illustrated that there were two major stages for weight loss of the EB‐form PANI powder sample. The first weight loss, at the lower temperature, resulted from the evaporation of moisture. The second weight loss, at the higher temperature, was due to the chemical structure degradation of the sample. The degradation temperature of the EB‐form PANI powder was around 420–450°C. The degradation temperature of emeraldine salt (ES)‐form PANI powder was lower (around 360–410°C) than that of the EB form (around 420–450°C). From the TGA results, I roughly estimated that 2.74 aniline repeat units, on average, were doped with 1 HNO3 molecule in the ES‐form PANI. I found a single crystalline morphology of EB‐form PANI, mostly like a conifer leaf. More complex, multilayered dendritic structures were also found. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2142–2148, 2003
Highly thermally conductive room‐temperature‐vulcanized silicone rubber and silicone grease
Authors: Wang Qian , Gao Wei , Xie Zemin
Published: June 2003

In this study, the effects of thermally conductive filler type (α‐Al2O3, SiC), volume fraction of the filler, and filler particle size distribution on the thermal conductivity and viscosity of room‐temperature‐vulcanized (RTV) silicone rubber and silicone grease were investigated. We were interested to find that silicone grease (or the RTV silicone rubber) had a maximum thermal conductivity (∼1.48 W/mK) and a minimum viscosity (∼3.4 × 104 mPa s), with a definite total volume fraction of the filler (0.55) when the distribution of filler sizes (the number ratio of two different particles sizes, i.e., 0.8 and 6 μm) was 600–700. We were able to increase the thermal conductivity of the RTV silicone rubber and silicone grease beyond 2 W/mK by increasing the total volume fraction of the filler with adequate filler size distributions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2397–2399, 2003
Thermodynamic theory of the viscoelasticity and yield of glassy polymers: Internal time theory
Authors: Cho Kwang Soo , Kim Sang Yong
Published: June 2003

A nonlinear viscoelastic constitutive equation of glassy polymers has been developed on the basis of the internal time and irreversible thermodynamics of internal variables. The constitutive equation is a generalization of spring–dashpot models and describes the yield behavior of glassy polymers. With this constitutive equation, the rate of entropy production has been determined to show a peak near the yield. We propose a new yield criterion, that yield occurs at the maximum rate of entropy production. The yield criterion is almost equivalent to that of peak stress and a thermodynamic interpretation of yield. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2400–2411, 2003
Preparation of magnetic ion‐exchange resins by the suspension polymerization of styrene with magnetite
Authors: Lee Yonghoon , Rho Joonho , Jung Bumsuk
Published: June 2003

Magnetic polymer microspheres composed of magnetite, styrene, and divinylbenzene were prepared by suspension polymerization to produce magnetic ion‐exchange resins (MIEXs). The magnetite was grafted with oleic acid to improve the magnetic properties of the MIEXs and to prevent the magnetite from flushing out of the MIEXs. The shape and magnetic properties of the magnetic microspheres were investigated with scanning electron microscopy and vibrating‐sample magnetometry. The average diameter of the prepared magnetic polymer microspheres was about 219 μm. The two types of MIEXs were prepared, magnetic cation‐exchange resins (MCEXs) and magnetic anion‐exchange resins (MAEXs). MCEX was prepared by sulfonation of magnetic polymer microspheres, and MAEX was made by a quaternization reaction with triethylamine of chloromethylated magnetic polymer microspheres. With diffuse‐reflectance Fourier transform infrared spectroscopy, elemental analysis, and acid–base titration, the degree of substitution and ion‐exchange capacity of the MIEXs were assessed. The efficiency of each MCEX and MAEX for the purification of contaminated water was examined with Co2+ and NO solutions, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2058–2067, 2003