bluuebunny/crossref_metadata_2025 huggingface dataset:
Phosphonium‐based layered silicate—Poly(ethylene terephthalate) nanocomposites: Stability, thermal and mechanical properties
Authors: Patro T. Umasankar , Khakhar Devang V. , Misra Ashok
Published: April 2009

PET‐clay nanocomposites were prepared using alkyl quaternary ammonium and phosphonium modified clays by melt‐mixing at 280°C using a micro twin screw extruder. The latter clays were prepared by synthesizing phosphonium surfactants using a simple one‐step method followed by a cation exchange reaction. The onset temperature of decomposition (Tonset) for phosphonium clays (>300°C) was found to be significantly higher than that of ammonium clays (around 240°C). The clay modified with a lower concentration (0.8 meq) of phosphonium surfactant showed a higher Tonset as compared to the clay modified with a higher concentration (1.5 meq) of surfactants. Nanocomposites prepared with octadecyltriphenyl phosphonium (C18P) modified clay showed a higher extent of polymer intercalation as compared with benzyltriphenylphosphonium (BTP) and dodecyltriphenylphosphonium (C12P) modified clays. The nanocomposites prepared with ammonium clays showed a significant decrease in the molecular weight of PET during processing due to thermal degradation of ammonium surfactants. This resulted in a substantial decrease in the mechanical properties. The molecular weight of PET was not considerably reduced during processing upon addition of phosphonium clay. The nanocomposites prepared using phosphonium clays showed an improvement in thermal properties as compared with ammonium clay‐based nanocomposites. Tonset increased significantly in the phosphonium clay‐based nanocomposites and was higher for nanocomposites which contained clay modified with lower amount of surfactant. The tensile strength decreased slightly; however, the modulus showed a significant improvement upon addition of phosphonium clays, as compared with PET. Elongation at break decreased sharply with clay. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Characterization of methyl‐substituted polyamides used for reverse osmosis membranes by positron annihilation lifetime spectroscopy and MD simulation
Authors: Shintani Takuji , Shimazu Akira , Yahagi Satoshi , Matsuyama Hideto
Published: April 2009

Three kinds of polyamides were synthesized from three diamines and 1,3,5‐benzenetricarbonyl trichloride (TMC). The diamines used were m‐phenylene diamine, N‐methyl‐m‐phenylenediamine, and N,N′‐dimethyl‐m‐phenylenediamine. The average free volume sizes of the polyamides were measured by positron annihilation lifetime spectroscopy (PALS), and the free volume fractions were evaluated by molecular dynamics (MD) simulations. The methyl substitution on amino groups of diamines brought about an increase in interstitial space of molecular chains of the polyamides. In addition, reverse osmosis (RO) membranes were prepared by interfacial polymerization from the three diamines and TMC. The increase in the degree of methyl‐substitution of diamines led to increased chlorine resistance and decreased salt rejections of the polyamide RO membranes. Thus, the methyl‐substitution of diamines significantly influenced membrane performance. The vacancy sizes and fractional volumes in polyamides evaluated by PALS measurement and MD simulation were well correlated with salt rejection of polyamide RO membranes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
PVDF–TiO2 composite hollow fiber ultrafiltration membranes prepared by TiO2 sol–gel method and blending method
Authors: Yu Li‐Yun , Shen Hong‐Mei , Xu Zhen‐Liang
Published: April 2009

Organic–inorganic polyvinylidene fluoride (PVDF)–titanium dioxide (TiO2) composite hollow fiber ultrafiltration (UF) membranes were prepared by TiO2 sol–gel method and blending method, respectively. The membranes were characterized in terms of microstructure, hydrophilicity, permeation performance, thermal stability, and mechanical strength. The experimental results indicated that PVDF–TiO2 composite UF membranes exhibited significant differences in surface properties and intrinsic properties because of the addition of inorganic particles. The TiO2 particles improved the membrane strength and thermal stability of PVDF–TiO2 composite UF membranes. In particular, hydrophilicity and permeability increased dramatically with the increase of TiO2, whereas the retention property of UF membranes was nearly unchanged. However, high TiO2 concentration induced the aggregation of particles, resulting in the decline of hydrophilicity and permeability. Compared with PVDF–TiO2 composite hollow fiber UF membranes prepared by TiO2 blending method, PVDF–TiO2 composite hollow fiber UF membranes prepared by TiO2 sol–gel method formed a dispersed inorganic network, and the stronger interaction between inorganic network and polymeric chains led to TiO2 particles being uniformly dispersed in UF membranes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Two‐phase composite modeling of polyurea/wood interfaces
Authors: Sonnenschein Mark F. , Brune Douglas A. , Wendt Benjamin L.
Published: April 2009

The flexural modulus of oak and pine boards suffused with polymeric methylene diphenyl diisocyanate (pMDI) was measured as a function of the amount of pMDI imbibed. The resulting modulus values were compared to predicted values calculated by assuming a relationship between the composite phases. Specifically, the measured flexural moduli were compared to values obtained from a Kerner model, in which the composite phase consists of isolated and spherical particulate isotropically arranged in the major phase. Results were also compared to a Davies model, in which the two phases exist in a bonded co‐continuous morphology. The measured data was shown to be well fit to the Kerner model and not well described by the Davies model, despite the fact that the Davies model is more physically descriptive of the filled wood pore structure. This incongruous result indicates that the pMDI/wood interface is weak, and the resulting tensile properties are not significantly different from the wood–air composite in the absence of pMDI. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis, characterization, and thermal and antimicrobial studies of newly developed transition metal–polychelates derived from polymeric Schiff base
Authors: Nishat Nahid , Parveen Shadma , Dhyani Swati , Asma  , Ahamad Tansir
Published: April 2009

Monomeric Schiff base derived from salicylaldehyde and 1,3‐diaminopropane was subjected to polycondensation reaction with formaldehyde and piperazine in basic medium. The resin was found to form polychelates readily with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) metal ions. The materials were characterized by elemental analysis, spectral studies (IR, 1H‐NMR, 13C‐NMR, and UV–visible), magnetic moment measurements, and thermal analysis. The electronic spectra and magnetic moment measurements of the synthesized polychelates confirmed the geometry of the central metal ion. Metal–resin bonds were registered in the IR spectra of the polychelates. The thermogravimetric analysis data indicated that the polychelates were more stable than the corresponding polymeric Schiff base. All the synthesized metal–polychelates showed excellent antibacterial activities against the selected bacteria. The antimicrobial activities were determined by using the shaking flask method, where 25 mg/mL concentrations of each compound were tested against 105 CFU/mL bacteria solutions. The number of viable bacteria was calculated by using the spread‐plate method, where 100 μL of the incubated antimicrobial agent in bacteria solutions were spread on agar plates, and the number of bacteria was counted after 24 h of incubation period at 37°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A microwave‐assisted process for coating polymer and glass surfaces with semiconducting ZnO submicron particles
Authors: Irzh Alexander , Gedanken Aharon
Published: April 2009

A new method for coating glass slides with ZnO particles with an average size of 200 nm is proposed in the current article. The coating was performed under microwave radiation. Two main morphologies are found for the ZnO crystals that are deposited on glass slides. The first morphology is that of a very dense coating of ZnO hexagonal rods growing perpendicular to the glass surface. The second is the growth of ZnO flower‐like particles. In addition to coating the glass by ZnO particles, we also report on coating other polymers [poly(methyl methacrylate) plate, polycarbonate beads, Nylon 6,6 beads, and polypropylene beads) by ZnO. The morphology obtained for ZnO coated on polymers is different from that detected for coating ZnO on glass. The unorganized coating of ZnO rods on polymers has been observed. The coated glass slides were characterized by X‐ray diffraction, volumetric titration, EDS, scanning electron microscope, and optical measurements (DRS and transmittance spectroscopy). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of tridentate phenoxy‐imine ligand [N,N,O] nickel(II) and palladium(II) complexes and their catalytic behaviors in vinyl polymerization of norbornene
Authors: Li Aike , Chen Jianxin , Zhang Li , Li Zhongshui , Zhu Meiping , Zhang Wenjie , Lin Xinrong , Zhang Zhichun
Published: April 2009

In this study, new complexes LNiCl(1), LNiBr(2), LNiI(3), and LPdCl(4) (L = 4,6‐di‐tert‐butyl‐2‐(N‐(quinolin‐8‐yl)iminomethyl)phenolato) have been synthesized and characterized. X‐ray diffraction studies on Complexes 1 and 4 revealed that N, N, O, and halogen atoms coordinated to metal, with a nearly square planar geometries in all cases. All these complexes are robust and exhibit high activities for the addition polymerization of norbornene (NB) with methylaluminoxane as cocatalyst [up to 47.62 kg PNB(mmol of Ni)−1h−1] and also lead to various activities and molecular weights of polynorbornenes under different reaction conditions. It is noteworthy that Complexes 1 and 4 show better activity under higher reaction temperature of 80°C. However, Complex 2 showed lower activity, and Complex 3 was found nearly inert toward NB polymerization, probably, because of thermal instability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Reactions of stoichiometric intumescent paints
Authors: Horacek Heinrich
Published: April 2009

Under the influence of heat intumescent paints with stoichiometric compositions decomposed to defined compounds: Ammonium polyphosphate degraded to polyphosphoric acid and ammonia. Polyphosphoric acid reacted with pentaerythritols and glycerol to cyclic phosphoric acid esters, which were identified as the blowing agents. Melamine and polyphosphoric acid combined to melamine polyphosphate and dipolyphosphate. In further degradation of polyphosphoric acid, it dehydrated to phosphorus pentoxide, which reacted with titanium dioxide further to titanium pyrophosphate. Intumescent paints with higher efficiency could be developed by the addition of glycerol, which reacted to phosphoric esters with lower temperatures of decomposition. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Induction of chemical and moisture resistance in Saccharum spontaneum L fiber through graft copolymerization with methyl methacrylate and study of morphological changes
Authors: Kaith Balbir Singh , Jindal Rajeev , Maiti Mithu
Published: April 2009

In this article, morphological modification of Saccharum spontaneum L, a natural fiber through graft copolymerization with methylmethacrylate using ferrous ammonium sulfate—potassium per sulfate redox initiator has been reported. Different reaction parameters such as reaction temperature, time, initiator molar ratio, monomer concentration, pH and solvent were optimized to get maximum graft yield (144%). The graft copolymers thus formed were characterized by Fourier transform infrared, scanning electron microscopy, X‐ray diffraction and thermogravimetric, differential thermal analysis, and differential thermogravimetric techniques. Graft copolymer has been found to be more moisture resistant and also showed higher chemical and thermal resistance. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Swelling behavior and metal ion retention from aqueous solution of hydrogels based on N‐1‐vinyl‐2‐pyrrolidone and N‐hydroxymethylacrylamide
Authors: Marambio Oscar.G. , Pizarro Guadalupe del C. , Jeria‐Orell Manuel , Geckeler Kurt E.
Published: April 2009

Hydrophilic copolymer gels were prepared by free‐radical copolymerization of 1‐vinyl‐2‐pyrrolidone (NVP) and N‐hydroxymethyl acrylamide (HMAm). The ratios of both monomers and crosslinker agent (CA) were varied, and the effect of external stimuli such as pH of the swelling media and inorganic ion interaction were investigated. The gels showed a pH‐responsive behavior. The interactions of inorganic ions with the hydrophilic hydrogels were determined as a function of pH, copolymer composition, and variation of the composition crosslinking degree. Additionally, a decrease of the pH of the solution caused a decrease in the equilibrium degree of swelling of the copolymer gels. The capacity to remove several metal ions such as Cu(II), Cr(III), Co(II), Zn(II), Ni(II), Cd(II), and Fe(III) in the aqueous phase was determined by using the liquid‐phase polymer‐based retention (LPR) technique. In addition, the copolymers and their complexes with transition metal ions were characterized by the monomer reactivity ratios by using the Kelen‐Tüdös method, elemental analysis, FTIR and 1H‐NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Based on the results of swelling and retention capacity of metal ions of poly(NVP‐co‐HMAm), it was concluded that the swelling and retention capacity properties of the hydrogels depends on the reaction environment's pH. This is regarded as a functional hydrogel, which could be employed as biodegradable materials for applications in agriculture chemicals and as drug delivery systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation of honeycomb films from nitryl poly(ether ether ketone)s via water‐droplet templating
Authors: Zhang Pei , Jiao Qingze , Zhao Yun , Tian Ye , Li Qingyun , Wang Xiaolin
Published: April 2009

The fabrication of honeycomb‐patterned films from nitryl poly(ether ether ketone)s (PEEK‐NO2) in a high‐humidity atmosphere was reported in this article. PEEK‐NO2 was prepared through acid (nitric acid and sulfuric acid) nitration from poly(ether ether ketone)s (PEEK). The obtained polymer, which was characterized by Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), and differential scanning calorimetry (DSC) showed excellent solubility and thermal stability. Some influence factors on the pattern formation and the fabrication of the porous structure, such as the solution concentration, the solvent, and the atmosphere humidity, were investigated. The results showed that with the increase of the solution concentration, the aperture of the film diminished gradually; the lower the solvents´ boiling point were, the smaller the films´ apertures were and the more regular the pores´ arrange; only under high‐humidity circumstances could obvious and ordered honeycomb films be formed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The ultrasound‐based interfacial treatment of aramid fiber/epoxy composites
Authors: Dong Huijuan , Wu Jian , Wang Guiying , Chen Zhigang , Zhang Guangyu
Published: April 2009

The quality of interfacial adhesion of aramid/epoxy composites affects the mechanical performance of the material, and thus there is a need to improve the condition by using the ultrasound‐based interfacial treatment. To do so, an ultrasonic transducer has been developed and evaluated under various operational conditions when it is installed in the winding system. It has demonstrated several key characteristics such as low power, high amplitude (more than 80 μm), and continuous working (more than 8 h) without water‐cooling. Subsequently, experiments were carried out to determine the mechanical performance of the polymer material with and without ultrasound treatment, showing that the ultrasonic treatment has improved the interfacial performance up to 10%, compared with those without any ultrasound‐treatment. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Kinetics of alkaline hydrolysis and morphologies of novel poly(ethylene terephthalate) micro‐porous hollow fibers and functional characteristics of fabrics
Authors: Tsen Wen‐Chin , Hsiao Kai‐Jen , Shu Yao‐Chi
Published: April 2009

This investigation explores the kinetics of the alkaline hydrolysis of regular poly(ethylene terephthalate) (PET) solid fibers and PET micro‐porous hollow fibers, using statistical regression analysis. Statistical regression analysis results concerning the kinetics of the alkaline hydrolysis of regular PET solid fibers and PET micro‐porous hollow fibers yielded a β value of 1. The R2 of the kinetic equation for α values from 1.07 to 1.16 exceeded that for α = 1. The rate constants of alkaline hydrolysis followed the order PET micro‐porous hollow fibers ≫ regular PET solid fibers. A morphology of large pores of diameter 0.1–3.5 μm was observed following alkali treatment of the PET micro‐porous hollow fibers. The weight loss percentage of the hollow fibers was around 20%. The hollowness of the PET micro‐porous hollow fibers after alkali treatment was between 30 and 32%. The PET micro‐porous hollow fibers exhibited simultaneous water‐absorption/release and keep‐warm functions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Reactive extrusion of zein with glyoxal
Authors: Selling Gordon W. , Woods Kristen Kruger , Biswas Atanu , Willett J. L.
Published: April 2009

Cross‐linked zein has been produced using glyoxal (GLY) as the cross‐linking reagent via reactive extrusion for the first time in a twin screw extruder using dilute sodium hydroxide as catalyst. Tri(ethylene glycol) was used as a plasticizer for various items. The extrudate was then ground and processed using either compression or injection molding. At the highest level of GLY (6%), tri(ethylene glycol) was used at 10% as a plasticizer to allow further processing to take place. With this formulation, samples could be obtained from the injection mold, however, the samples did not hold their molded shape due to the elasticity of the sample at the mold temperature. When lower levels of GLY were used, injection molded sample bars of similar quality to control were obtained. The physical properties of these samples were similar to control. At GLY levels of 1.75% and higher, the samples were resistant to dissolution by acetic acid. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Dynamically vulcanized blends of polypropylene and ethylene‐octene copolymer: Comparison of different peroxides on mechanical, thermal, and morphological characteristics
Authors: Babu R. Rajesh , Singha Nikhil K. , Naskar Kinsuk
Published: April 2009

Thermoplastic vulcanizates (TPVs) are prepared by the dynamic vulcanization process, where crosslinking of an elastomer takes place during its melt mixing with a thermoplastic polymer under high shear. TPVs based on polypropylene (PP) with different grades of ethylene‐octene copolymers (EOC) were prepared with a coagent assisted peroxide crosslinking system. The effect of dynamic vulcanization and influence of various types and concentrations of peroxide were mainly studied on the basis of the mechanical, thermal, and morphological characteristics. Three structurally different peroxides, namely dicumyl peroxide (DCP), tert‐butyl cumyl peroxide (TBCP), and di‐tert‐butyl peroxy isopropyl benzene (DTBPIB) were investigated. The mechanical properties of the TPVs are primarily determined by the extent of crosslinking in the EOC and the degree of degradation in the PP phase. Among all peroxides used DCP gives best overall properties with low‐molecular‐weight EOC, whereas TBCP shows best property level with high‐molecular‐weight EOC‐based TPVs. These can be explained on the basis of the molecular characteristics of EOC and the nature of the peroxide used. Differential scanning calorimetery (DSC) and morphological analysis reveal that PP and EOC are a thermodynamically immiscible system. The melting endotherm was studied to determine the influence of various peroxides on crystallinity of the PP phase. Tensile fracture patterns were also analyzed to study the failure mechanism of the samples. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of temperature on polyethylene teraphthalate coated ECCS plates in acetic‐acetate medium
Authors: Zumelzu E. , Rull F. , Ortega C. , Cabezas C.
Published: April 2009

Electrolytic chromium‐coated steel plates with a polyethylene teraphthalate (PET) polymer coating, used in the manufacturing of both flat and rippled wall cans and containers, were submitted to 40, 60, and 80°C heating in an acetic‐acetate medium and to electrochemical polarization tests, to study the PET coating degradation and the structural changes leading to a loss of the protection capacity of the steel, as well as to determine the detachment at the interface level. The samples were analyzed by Raman vibrational spectroscopy, micro‐Raman, and attenuated total reflection to evaluate changes in the composition and structure of the coatings. Also, the PET surface was characterized by scanning electron microscopy (SEM) to establish the coating degradation. Spectroscopy analyses showed small changes of crystallinity in the PET thickness at 80°C and a reduced effect of the mechanical forming of plates on crystallinity. The SEM characterization evidenced the presence of surface defects and failures on the coating caused by the acetic‐acetate medium. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of gel spinning accompanied with cross‐linking using boric acid on the structure and properties of high‐molecular‐weight poly(vinyl alcohol) fiber
Authors: Jo Yong Gu , Shin Eun Joo , Lee Young Jae , Yoon Won Sik , Han Sung Soo , Lee Yang Hun , Lee Yong Rok , Noh Seok Kyun , Gal Yeong Soon , Lyoo Won Seok
Published: April 2009

To enhance the thermal stability of poly(vinyl alcohol) (PVA) fiber, the fiber was prepared from the gel spinning of high molecular weight (HMW) PVA by using dimethyl sulfoxide/water (8/2, v/v) as a solvent, accompanied with the cross‐link by boric acid (B‐PVA). In addition, the structure and properties of the B‐PVA fiber were compared with those of the HMW PVA fiber obtained by using the same spinning system without cross‐linking (NB‐PVA). Through a series of experiments, it turned out that cross‐linking actualized by an optimum amount of boric acid (0.3 wt % based on PVA) and zone drawing caused significant changes in the properties of HMW PVA gel fiber. That is, cross‐linking increased thermal degradation temperatures at each degradation step and amounts of final residues, resulting in improving thermal properties of the PVA fiber. On the contrary, it was found that in the case of the B‐PVA fiber, some broadening of the original PVA unit cell occurred, which was identified by the peak shift to lower angle in X‐ray diffractogram. The tensile strength and Young's modulus of B‐PVA fiber with draw ratio of 15 are 23.1 and 308.3 g/d, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Nanocomposites of styrene–butadiene rubber and synthetic anatase obtained by a colloidal route and their photooxidation
Authors: Arantes Tatiane M. , Leite Edson R. , Longo Elson , Camargo Emerson R.
Published: April 2009

Photodegradable styrene–butadiene rubber (SBR)/TiO2 nanocomposites were prepared by a colloidal route through the simple mixing of a commercial polymer latex and synthetic anatase nanoparticles. Stable colloids of pure anatase TiO2 nanoparticles with an average diameter of 7 nm were prepared by a solvothermal route from the hydrolysis of titanium alkoxide by hydrogen peroxide in the presence of oleic acid. The photocatalytic degradation of the SBR–TiO2 nanocomposites was carried out in ambient air at room temperature under a UV lamp and was monitored by Fourier transform infrared and UV–visible spectroscopies and differential scanning calorimetry. The results show that the SBR–TiO2 nanocomposites were photocatalytically degraded under UV light, which indicate that the butadiene chains in the nanocomposite were oxidized during UV irradiation. Thermal analysis measurements indicated that crosslinking reactions occurred. The presence of anatase TiO2 nanoparticles was found to accelerate the photocatalytic process, and the degradation mechanism was similar to that of the pure SBR polymer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Poly(L‐lactic acid) nanocomposites with layered double hydroxides functionalized with ibuprofen
Authors: Dagnon Koffi L. , Ambadapadi Sriram , Shaito Ali , Ogbomo Sunny M. , DeLeon Vallerie , Golden Teresa D. , Rahimi Maham , Nguyen Kytai , Braterman Paul S. , D'Souza Nandika Anne
Published: April 2009

The detrimental effect of cell adhesion on polymer surfaces has been a limiting factor in the medical deployment of many implants. We examined the potential to decrease cell proliferation while simultaneously increasing mechanical performance through Zn–Al layered double hydroxide (LDH) organically modified with ibuprofen dispersed in poly(L‐lactic acid) (PLLA). These composites are commonly referred to as nanocomposites. The thermophysical and mechanical properties of the hybrids were studied with wide‐angle X‐ray diffraction (WAXD), transmission electron microscopy (TEM), differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, and tensile testing. The WAXD and TEM results indicated that intercalated and exfoliated nanocomposites were obtained. The storage modulus, tensile modulus, and ultimate tensile strength were improved. The LDH affected the cold crystallization and reduced the thermal stability of the neat PLLA. Smooth muscle cells were used for in vitro studies of the nanocomposites. It was found that the hybrids reduced cell proliferation, and the amount of cell reduction was related to ibuprofen release. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of different interphases on the mechanical properties of cured silanized silica‐filled styrene–butadiene/polybutadiene rubber blends for use in passenger car tire treads
Authors: Ostad‐Movahed S. , Ansarifar A. , Song M.
Published: April 2009

Polybutadiene (BR) and styrene–butadiene (SBR) rubbers containing the same loading of precipitated silica nanofiller were prepared. The silica surfaces were pretreated with bis(3‐triethoxysilylpropyl) tetrasulfide to chemically bond the silica to the rubber. The rubber compounds were mixed together for different times and at different temperatures to produce SBR/BR blends. The mass fraction and composition values of the interphases in the blends were subsequently determined with modulated‐temperature differential scanning calorimetry. These properties changed substantially as a function of mixing temperature and mixing time. The hardness, tensile strength, elongation at break, stored energy density at break, tear strength, modulus, abrasion resistance, heat buildup, and loss tangent of the cured blends were measured over a wide range of test conditions. Elongation at break, stored energy density at break, tearing energy, and abrasion resistance benefited from increases in the mass fraction of the interphase. The remaining properties were influenced mainly by the filler loading and mixing time of the two rubber compounds. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Poly[4‐(4‐vinylbenzyloxy)‐2‐hydroxylbenzaldehyde] for rapid removal of low concentrations of Pb(II)
Authors: Amoyaw Prince , Ingram Conrad , Hsu Fu‐Lian , Bu Xiu R.
Published: April 2009

Poly[4‐(4‐vinylbenzyloxy)‐2‐hydroxylbenzaldehyde] was evaluated for removing low concentrations of lead(II) in ppb levels from aqueous media. The effects of the pH condition and the initial lead concentrations on removal were examined. It was found that the metal absorption is best described with the Langmuir model. The RL values obtained between 0.01 and 0.23 indicate that favorable absorption occurs in the studied concentration ranges. The kinetic study revealed that the metal removal proceeds at a very fast pace—less than 30 s—to reach the maximum capacity. The data fit the description of pseudo–second‐order rate. The dynamic column study for real‐time practical absorption also was investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The effects of spinning temperature on morphologies and properties of polyethersulfone hollow fiber membranes
Authors: Zhu Li‐Ping , Yu Jing‐Zhen , Xu You‐Yi , Zhu Bao‐Ku
Published: April 2009

Polyethersulfone (PES) hollow fiber membranes were prepared by traditional dry‐wet spinning technique. Scanning electronic microscopy (SEM) was used to characterize membrane morphologies, and the membrane properties were evaluated via bubble point measurements and ultrafiltration experiments. The effects of spinning temperature on the morphologies and properties of PES fibers were investigated in detail. At a high spinning temperature, the obtained membrane structure consisting of a thin skin‐layer and loose sponge‐like sublayer endows PES membrane with not only good permeability, but also high solute rejection. Based on the determination of ternary phase diagrams and light transmittance curves, the relationship of membrane morphologies with thermodynamics and precipitation kinetics of membrane‐forming system was discussed. It was concluded that the morphologies and properties of PES hollow fiber membrane could be conveniently tuned by the adjustment of the spinning temperature and air gap. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Thermally responsive poly[N‐isopropylacrylamide‐co‐2‐hydroxyethylacrylate] colloidal crystals included in β‐cyclodextrin for controlled drug delivery
Authors: Mathews Anu Stella , Cho Won‐Jei , Kim Il , Ha Chang‐Sik
Published: April 2009

Novel temperature‐sensitive poly[N‐isopropylacrylamide‐co‐2‐hydroxyethylacrylate] [P(NIPAAm‐HEAc)] colloidal crystals containing β‐cyclodextrin (β‐CD) were prepared. These reversibly tunable supramolecular inclusion complexes display brilliant colors, due to the self‐assembly of several structured nanoparticles to form crystal structures. The hydrogels displayed rainbow colors upon the variation of the β‐CD concentration and can be made either visible or invisible by simply changing the temperature. The inclusion complexes were characterized using NMR spectroscopy, laser light scattering, UV–visible spectroscopy, and viscometer measurements. Compared with the conventional poly(N‐isopropylacrylamide) gel, the β‐CD‐incorporated hydrogels in aqueous solution showed a lower critical solution temperature of about 57°C, which can be attributed to the hydrogen bonding between P(NIPAAm‐HEAc) included in β‐CD and water, which is enhanced by the hydrophilic groups of β‐CD. The use of these materials as drug carriers was also evaluated by making use of their thermo‐responsive behavior. The release time of a model drug, 5‐fluorouracil (5‐FU), from the novel inclusion complexes was prolonged in comparison to that from P(NIPAAm‐HEAc) without β‐CD. The significance of the present drug delivery system is the mixing of the gel and drug without any chemical reaction at room temperature, resulting in a gelled drug depot for slow and controlled release. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Electrospinning fabrication and characterization of poly(vinyl alcohol)/montmorillonite nanofiber mats
Authors: Lee Hyun Woo , Karim Mohammad Rezaul , Ji Hyun Mi , Choi Jin Hyun , Ghim Han Do , Park Sung Min , Oh Weontae , Yeum Jeong Hyun
Published: April 2009

Poly(vinyl alcohol) (PVA)/montmorillonite clay (MMT) nanofiber mats have been fabricated by the electrospinning technique. The PVA/MMT nanofiber mats were characterized by X‐ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and mechanical measurements. The study showed that the introduction of MMT results in improvement in tensile strength, and thermal stability of the PVA matrix. XRD patterns and SEM micrographs suggest the coexistence of exfoliated MMT layers over the studied MMT contents. FTIR revealed that there might be possible interaction occurred between the MMT clay and PVA matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Dielectric properties of nanotube reinforced butyl elastomer composites
Authors: Dang Thi To Nga , Mahapatra S. P. , Sridhar V. , Kim J. K. , Kim K‐J. , Kwak H.
Published: April 2009

Dielectric relaxation behavior of multiwalled carbon nanotube reinforced butyl rubber composites has been studied as a function of variation in filler in the frequency range of 20–2 × 106 Hz. The effect of variation in filler loadings on the complex and real parts of impedance was distinctly visible, which has been explained on the basis of interfacial polarization of fillers in a heterogeneous medium and relaxation dynamics of polymer chains in the vicinity of fillers. The electric modulus formalism has been used to further investigate the conductivity and relaxation phenomenon. The frequency dependence of AC conductivity has been investigated by using Percolation theory. The phenomenon of percolation in the composites has been discussed based on the measured changes in electric conductivity and morphology of composites at different concentrations of the filler. The percolation threshold as studied by AC conductivity occurred in the vicinity of 6–8 phr of filler loading. Scanning electron microscope microphotographs showed agglomeration of the filler above this concentration and formation of a continuous network structure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Thermal and crystallization properties of PBT/ABAS blends
Authors: Tomar Neetu , Maiti S. N.
Published: April 2009

Blends of poly(butylene terephthalate) (PBT) with poly(acrylonitrile‐butyl acrylate‐styrene) (ABAS) were characterized by differential scanning calorimetry, infrared, thermogravimetric analysis, and wide‐angle X‐ray diffraction (WAXD) studies. Addition of ABAS polymer to PBT improved the thermal stability of PBT. Infrared studies showed that ABAS polymer chemically interacts with PBT. The crystallization behavior of PBT was modified in the presence of ABAS polymer. The ABAS polymer showed inappreciable effect on melting behavior of PBT but decreased its crystallization. WAXD studies showed some modification in PBT peaks and a peak with increasing intensity corresponding to the β‐crystalline form of PBT. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Optimization of PVC– PAN‐based polymer electrolytes
Authors: Rajendran Somasundaram , Babu Ravishanker , Sivakumar Periyasami
Published: April 2009

The hybrid plasticized polymer electrolyte composed of the blend of poly(vinyl chloride) (PVC) and poly(acrylonitrile) (PAN) as host polymer, propylene carbonate as plasticizer, and LiClO4 as a salt was studied. An attempt was made to optimize the polymer blend ratio. XRD, Fourier transform infrared, and DSC studies confirm the formation of polymer–salt complex and miscibility of the PVC and PAN. The electrical conductivity and temperature dependence of ionic conductivity of polymer films are also studied and reported here. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and characterization of cross‐linked polymeric nanoparticles for enhanced oil recovery applications
Authors: Al‐Manasir Nodar , Kjøniksen Anna‐Lena , Nyström Bo
Published: April 2009

Chemically cross‐linked nanoparticles from dilute aqueous alkali solutions of hydroxyethylcellulose (HEC) in the presence of a cross‐linker agent (divinyl sulfone, DVS) were prepared from a reaction mixture, which was exposed to different stirring speeds during the cross‐linking process. At various stages during the cross‐linking procedure, the reaction was terminated and the species were characterized by means of turbidimetry, asymmetric flow field‐flow fractionation (AFFFF), dynamic light scattering (DLS), and rheo‐small‐angle light scattering (rheo‐SALS) methods. During the cross‐linking of a dilute polymer solution, the competition between intrapolymer and interpolymer is a prominent feature. The DLS results show that at early times in the cross‐linking process, intrachain cross‐linking with contraction of the complexes is promoted by high stirring speeds; at later times the growth of aggregates is inhibited by high stirring speeds. The results from the rheo‐SALS measurements disclosed that at early times during the cross‐linker reaction, the complexes are fragile against shear forces if the reaction mixture had been subjected to low stirring speeds. At a later state of cross‐linking, more cross‐links lead to better stability of the species, even for solutions that have been exposed to low stirring speeds during the cross‐linking process. This study shows that the sizes of the particles can be tuned by exposing the solutions to different stirring speeds during the cross‐linker reaction and to terminate the reaction at desired reaction times. The strategy discussed in this work for the preparation of particles of various sizes is of special interest in connection with enhanced oil recovery applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Phase structure and properties of poly(ethylene terephthalate)/high‐density polyethylene based on recycled materials
Authors: Lei Yong , Wu Qinglin , Clemons Craig M. , Guo Weihong
Published: April 2009

Blends based on recycled high density polyethylene (R‐HDPE) and recycled poly(ethylene terephthalate) (R‐PET) were made through reactive extrusion. The effects of maleated polyethylene (PE‐g‐MA), triblock copolymer of styrene and ethylene/butylene (SEBS), and 4,4′‐methylenedi(phenyl isocyanate) (MDI) on blend properties were studied. The 2% PE‐g‐MA improved the compatibility of R‐HDPE and R‐PET in all blends toughened by SEBS. For the R‐HDPE/R‐PET (70/30 w/w) blend toughened by SEBS, the dispersed PET domain size was significantly reduced with use of 2% PE‐g‐MA, and the impact strength of the resultant blend doubled. For blends with R‐PET matrix, all strengths were improved by adding MDI through extending the PET molecular chains. The crystalline behaviors of R‐HDPE and R‐PET in one‐phase rich systems influenced each other. The addition of PE‐g‐MA and SEBS consistently reduced the crystalline level (χc) of either the R‐PET or the R‐HDPE phase and lowered the crystallization peak temperature (Tc) of R‐PET. Further addition of MDI did not influence R‐HDPE crystallization behavior but lowered the χc of R‐PET in R‐PET rich blends. The thermal stability of R‐HDPE/R‐PET 70/30 and 50/50 (w/w) blends were improved by chain‐extension when 0.5% MDI was added. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of functional polypropylene via solid‐phase grafting soft vinyl monomer and its mechanism
Authors: Wang Jian , Wang Dengfei , Du Wei , Zou Enguang , Dong Qun
Published: April 2009

Solid‐phase grafting of a soft vinyl monomer, butyl methylacrylate (BMA), onto polypropylene (PP) matrixes with 2,2′‐azobisisobutyronitrile (AIBN) as initiator was carried out to enhance the polarity of polymer. Soft vinyl monomer was a novel notion in grafting modification of PP. Effects of swell time, BMA concentration, AIBN concentration, grafting reaction time, and temperature on grafting percentage (Gp) and grafting efficiency (Ge) were examined. The optimal conditions of grafting reaction were obtained: swell time of 60 min, BMA concentration of 6 wt %, AIBN concentration of 0.05 wt %, reaction temperature of 85°C, and reaction time of 2 h. The grafting samples were investigated by such characterization techniques as Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and scanning electron microscope (SEM) analysis. FTIR results indicated that BMA was actually grafted onto PP backbone. TGA results showed that the decomposition temperature increases with addition of BMA into PP backbone. SEM results indicated that the surfaces of PP‐g‐BMA had a markedly bumpy texture, whereas the pure PP surface was very smooth. Water contact angle results showed that the polarity and hydrophilicity of PP were improved effectively. Compared with the traditional monomer MAH, Gp, and Ge, melt flow rate and mechanical property results all indicated that the soft vinyl monomer had a many advantages in the modification of PP. In the end, the mechanism of solid grafting was discussed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Influence of compatibilizer on notched impact strength and fractography of HDPE–organoclay composites
Authors: Rattanawijan Waraporn , Amornsakchai Taweechai , Amornsakchai Pornsawan , Petiraksakul Pinsupha
Published: April 2009

The focus of this study was the notched impact property of high‐density polyethylene (HDPE)–organoclay composites and the resultant morphology of impact‐fractured surfaces. Composites with a different organoclay content and degree of organoclay dispersion were compared with neat HDPE under identical conditions. The degree of organoclay dispersion was controlled through the use of a compatibilizer, maleic anhydride grafted polyethylene. It was found that the addition of organoclay can slightly increase the elastic modulus and notched impact strength of the composite. When the level of organoclay dispersion was improved by using compatibilizer, elastic modulus and toughness further increased. A significant increase in yield strength was also notable. The presence of organoclay was found to suppress strain hardening of the matrix during tensile testing. The impact‐fractured surfaces of failed specimens were studied with scanning electron microscopy. The micromechanism for the increased toughness of HDPE–organoclay composites was discussed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of polymers from soybean oil and p‐dinitrosobenzene
Authors: Mutlu Hatice , Kusefoglu Selim H.
Published: April 2009

In this study, rubbery, bio‐based thermoset polymers were synthesized from soybean oil (SO) and p‐dinitrosobenzene (DNB) via an ene reaction. Polymeric p‐dinitrosobenzene (PDNB) was synthesized from p‐quinone dioxime and was thermally depolymerized in the presence of SO. SO/PDNB polymers were synthesized by a two‐stage polymerization. During the reaction, the role of different parameters such as mol ratio of SO and PDNB, preheating temperature of SO, polymerization time, and temperature were examined. Polymerization was followed by IR spectroscopy, and the polymers obtained were characterized by dynamic mechanical analysis, thermogravimetric analysis, and differential scanning calorimetry. The polymers have glass transition temperature ranging from −51.5°C to −46.3°C, whereas their storage moduli are between 430 and 210 MPa at −60°C. Thermogravimetric analysis reveals that all of the polymers have temperatures of maximum degradation around 500°C. The crosslinked network structure of the polymers was investigated by swelling behavior and surface hardness test. Methyl oleate was used as a model compound to examine the chemical structure of the products. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and application of CDA‐beta‐CD in controlling release of drug
Authors: Tan Ying , Hu Aixi , Xia Lin , You Tianbiao , Cao Jianhua
Published: April 2009

To chemically attach beta‐cyclodextrin (beta‐CD) molecules to cellulose diacetate (CDA), an isocyanate containing preformed polymer was synthesized by prepolymerization of CDA and toluene‐2,4‐diisocyanate (TDI), which was then grafted with beta‐CD. Effects of reaction temperature, time, and mixture ratio on reactions were observed. The structure of CDA‐beta‐CD was characterized by 1H‐ and 13C‐NMR spectra; the release of CDA‐beta‐CD with medicament naproxen by dynamic dialysis in the artificial simulated intestinal fluid (pH = 7.4) was studied in vitro. Results indicated that the release time could reach more than 8 h at a graft ratio of 68.7%, which showed a good controlled‐release drug effect. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Comparison of olefin copolymers as compatibilizers for polypropylene and high‐density polyethylene
Authors: Lin Yijian , Yakovleva Victoria , Chen Hongyu , Hiltner Anne , Baer Eric
Published: April 2009

Some polyolefin elastomers were compared as compatibilizers for blends of polypropylene (PP) with 30 wt % high‐density polyethylene (HDPE). The compatibilizers included a multiblock ethylene–octene copolymer (OBC), two statistical ethylene–octene copolymers (EO), two propylene–ethylene copolymers (P/E), and a styrenic block copolymer (SBC). Examination of the blend morphology by AFM showed that the compatibilizer was preferentially located at the interface between the PP matrix and the dispersed HDPE particles. The brittle‐to‐ductile (BD) transition was determined from the temperature dependence of the blend toughness, which was taken as the area under the stress–strain curve. All the compatibilized blends had lower BD temperature than PP. However, the blend compatibilized with OBC had the best combination of low BD temperature and high toughness. Examination of the deformed blends by scanning electron microscopy revealed that in the best blends, the compatibilizer provided sufficient interfacial adhesion so that the HDPE domains were able to yield and draw along with the PP matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of some new polyhydrazides by direct polycondensation in ionic liquid and their metallization through transition metal complexation
Authors: Abdolmaleki Amir , Varnamkhasti Somieh Kazemi
Published: April 2009

A series of new polyhydrazides has been synthesized via direct polycondensation of benzofuro[2,3‐b]benzofuran‐2,9‐dicarboxylic acid (BBDA) with dihydrazides in ionic liquids (ILs) as a new class of solvents, which have interesting properties, such as nonvolatility, high ionic concentration, good thermal stability, and nonflammability. Direct polycondensation is successfully proceeded in ILs and triphenyl phosphite (condensing agent) without any additional extra components, such as LiCl and pyridine, using in similar reactions in ordinary (IL can act as both solvent and catalyst). The polyhydrazides have been obtained in quantitative yield and their intrinsic viscosities ranged from 0.21 to 0.47 dL g−1. The polyhydrazides were characterized by means of IR, 1H‐NMR, inherent viscosity (ηinh), solubility test, TGA, DSC, CHN analysis, and ultraviolet λmax. They could be thermally converted into the corresponding poly(1,3,4‐oxadiazole)s approximately in the region of 210–330°C, as evidenced by the TGA thermograms.

The polymers were readily soluble in several organic polar solvents, such as DMAc, N,N‐dimethylformamide, dimethylsulfoxide, N‐methyl‐2‐pyrrolidone and could be cast into flexible films. The polymer were metallized via complexation with various transition metal. The complexes were investigated by X‐ray diffraction, IR, and UV spectrophotometry. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009