bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism of copper(II) adsorption by polyvinyl polyacrylate
Authors: Nakajima Akira , Sakai Naoko , Yamauchi Jun
Published: September 2006

The mechanism of copper adsorption by polyvinyl polyacrylate (PVPA) was examined using ESR and magnetic measurements. The copper adsorption by PVPA obeyed Langmuir adsorption isotherm with the maximum adsorption amounts of 4.17 mmol g−1 adsorbent, being larger than those of uranium adsorption. Though copper in the solution was completely adsorbed by the resin above pH 4, the ESR intensity was remained low level and only increased above pH 8. The ESR spectrum of Cu(II) ion in PVPA are axial type with tetragonally distorted octahedral symmetry, having parameters of g⊥ = 2.361, g⟂ = 2.057, |A⊥| = 14.0 m cm−1 (pH 5), and g⊥ = 2.329, g⟂ = 2.058, |A⊥| = 16.2 m cm−1, |A⟂| = 2.7 m cm−1 (pH 9). The absorption peaks originated from Cu(II)–Cu(II) dimer was also observed (pH 5). The paramagnetic susceptibility of PVPA adsorbed Cu(II) ion at pH 5 explained by the dimer model with |J| = 220 K. These results suggested that most of copper was adsorbed and formed dimer in PVPA, being similar to that in Cu(II)‐acetate monohydrate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5372–5377, 2006
Miscibility of styrene/unsaturated polyester quasibinary systems: Unsaturated polyester chemical composition and molecular weight influence
Authors: Buffa Fabián , Borrajo Julio
Published: September 2006

Unsaturated polyester prepolymers were synthesized with different chemical compositions and molecular weights. Cloud‐point curves (CPC) were measured in St‐UP quasibinary solutions, showing UCST behavior in all cases. The miscibility of the first UP samples series in St comonomer was enhanced when AA chemical comonomer concentration in UP prepolymer increased. In the second series, UP prepolymer miscibility increased with the molecular weight up to a maximum and, after that, the miscibility decreased. A thermodynamic analysis of experimental CPCs was performed using the Flory‐Huggins (F‐H) theory for polydisperse polymer solutions. A simple relationship between the interaction parameter and the temperature inverse could fit the measured CPCs in wide concentrations and molecular weight ranges. In the temperature interval where this fit took place, the positive enthalpic contribution to the interaction parameters determined the miscibility dependence with temperature in both UP sample series. The St‐UP miscibility behavior was also correlated with UPs structural chemical parameters as: (a) the final HO and HOOC high polar groups concentration, (b) the chain backbone polar adipate and phthalate groups concentration, and (c) the UP size dependent mixing entropy. All these parameters are molecular weight dependent. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6064–6073, 2006
Alginate‐coated chitosan membrane for guided tissue regeneration
Authors: Chen Ta Wei , Chang Shwu Jen , Niu Gregory Cheng‐Chie , Hsu Yun Ting , Kuo Shyh Ming
Published: September 2006

Chitosan membranes were first prepared by a thermally induced phase separation method and then alginate was coated on one side of the membranes by a modified dialysis apparatus to prepare alginate/chitosan membranes (A/C membranes). Electron spectroscopy for chemical analysis (ESCA), scanning electron microscope, and contact angle measurements were conducted to evaluate the surface characteristics. The mechanical strength, degradation behavior, and cell adhesion test were performed to evaluate the feasibility of using A/C membrane in guided tissue regeneration applications. The results revealed that alginates could effectively be coated onto the chitosan membrane. As observed in ESCA results, the N‐atomic emission peak was decreased from originally 6.2% on the untreated chitosan surface to 2% on the alginate‐treated surface. The contact angle decreased on the alginate‐modified side substantially, compared with the untreated side (from 88.4° to 34.2°). The A/C membrane had a higher water content of 71.8% in comparison to the chitosan membrane of 61.8%. Consequently, A/C membrane became stiffer and had a higher Young's modulus and strength. After a 30‐day in vitro shaking test, the weight of membranes was degraded to about 75% from the original. The 3T3 fibroblast cells showed less adhesion to alginate‐modified side as compared to the untreated chitosan‐side in cell adhesion test. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4528–4534, 2006
Poly(trimethylene terephthalate) nanocomposite fibers comprising different organoclays: Thermomechanical properties and morphology
Authors: Chang Jin‐Hae , Mun Mu Kyung , Kim Jeong‐Cheol
Published: September 2006

Poly(trimethylene terephthalate) (PTT) nano composites were synthesized by in situ polymerization at high temperature with two thermally stable organoclays: 1,2‐dimethylhexadecylimidazolium‐montmorillonite (IMD‐MMT) and dodecyltriphenyl phosphonium‐MMT (C12PPh‐MMT). PTT hybrid fibers with various organoclay contents were melt‐spun at various draw ratios (DRs) to produce monofilaments. The thermomechanical properties and morphologies of the PTT hybrid fibers were characterized using differential scanning calorimetry, thermogravimetric analysis, wide‐angle X‐ray diffraction, electron microscopy, and mechanical tensile properties analysis. The nanostructure of the hybrid fibers was observed by both scanning and transmission electron microscopy, which showed that the clay layers were well dispersed into the matrix polymer, although some clusters or agglomerated particles were also detected. Unlike the hybrids containing IMD‐MMT, the clay layers of the C12PPh‐MMT hybrid fiber were more dispersed into the matrix polymer. The thermal stability and tensile properties of the hybrid fibers increased with increasing clay content for DR = 1. However, as DR increased from 1 to 9 the ultimate strength and initial modulus of the hybrid fibers with IMD‐MMT increased slightly whereas those of C12PPh‐MMT hybrid fibers decreased slightly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4535–4545, 2006
Effect of formulation variables on the prediction of release from microparticles with experimental design
Authors: Luzardo‐Alvarez A. , Almeida‐Prieto S. , Fraga‐López F. , Otero‐Espinar F. , Rodriguez‐Núñez E. , Martinez‐Ageitos J. , Blanco‐Méndez J.
Published: September 2006

Different formulations of triamcinolone acetonide (TA) encapsulated in microparticles (MPs) based on poly(D,L‐lactide‐co‐glycolide) (PLGA), poly(ϵ‐caprolactone) (PCL), and poly(methyl vinyl ether‐co‐maleic anhydride) (Gantrez AN119) blends were obtained by spray‐drying with a mixture experimental design. The goal of this study was to investigate the influence of the mixture composition, particle size, particle shape, enthalpy of melting (ΔHm) of PCL, enthalpy of depolymerization of PLGA, and glass‐transition temperature of Gantrez on drug release at pH 1.2 and 6.8. The presence of Gantrez in the MPs made PCL more amorphous because of the reduction of its ΔHm. The determination of the activation energy (Ea) associated with TA release from the MPs was used to calculate the fitting equation of the drug‐release profile, and subsequently, a thermodynamic (Arrhenius‐like) model was established. Drug release increased as Ea and ΔHm decreased. Our results suggest that this approach was capable of predicting in vitro TA release from these MPs, which allowed us to develop formulations with low‐release patterns at pH 1.2 and to modulate drug release at enteric pH. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4546–4553, 2006
Rheology of silicon carbide/vinyl ester nanocomposites
Authors: Yong Virginia , Hahn H. Thomas
Published: September 2006

Silicon carbide (SiC) nanoparticles with no surface treatment raise the viscosity of a vinyl ester resin much more intensely than micrometer‐size SiC particles. An effective dispersant generally causes a reduction in the resin viscosity attributed to its surface‐active properties and thereby increases the maximum fraction of particles that can be introduced. This article assesses the rheological behavior of SiC‐nanoparticle‐filled vinyl ester resin systems with the Bingham, power‐law, Herschel–Bulkley, and Casson models. The maximum particle loading corresponding to infinite viscosity has been determined to be a 0.1 volume fraction with the (1 − ηr−1/2)–ϕ dependence (where ηr is the relative viscosity and ϕ is the particle volume fraction). The optimum fractional weight percentage of the dispersants (wt % dispersant/wt % SiC) is around 40% for 30‐nm SiC nanoparticles, which is much higher than 1–3% for micrometer‐size particles. SiC nanoparticles at a concentration of 9.2 wt % (0.03 volume fraction) cause a fourfold increase in the resin viscosity. The addition of a dispersant at the optimum dosage lowers the viscosity of SiC/vinyl ester suspensions by 50%. The reduction in the viscosity is substantial to improve the processability of SiC/vinyl ester nanocomposites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4365–4371, 2006
Synthesis, characterization, and thermal behavior study of methyl methacrylate polymers containing 4‐carbazole substitutes
Authors: Babazadeh Mirzaagha
Published: September 2006

A new polymerizable monomer, [4‐(9‐ethyl)carbazolyl]methyl methacrylate (2), was synthesized by reacting of methacrylic acid and 4‐hydroxymethyl‐9‐ethyl carbazole (1) by esterification procedure in the presence of N,N′‐dicyclohexylcarbodiimide. The resulting monomer was then polymerized free‐radically to form the poly(methyl methacrylate) containing 4‐(9‐ethyl)carbazolyl pend ent groups. Also, copolymerization of monomer 2 with various acrylic monomers such as methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, and n‐butyl acrylate by azobisisobutyronitrile as a free radical polymerization initiator gave the related copolymers in high yields. The structure of all the resulted compounds was characterized and confirmed by FTIR and 1H NMR spectroscopic techniques. The average molecular weight of the obtained polymers was determined by gel permeation chromatography using tetrahydrofurane as the solvent. The thermal gravimetric analysis and differential scanning calorimeter instruments were used for studying of thermal properties of polymers. It was found that, with the incorporation of bulky 4‐(9‐ethyl)carbazolyl substitutes in side chains of methyl methacrylate polymers, thermal stability and glass transition temperature of polymers are increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4989–4995, 2006
Thermal behavior and morphological characteristics of cationic dyeable poly(ethylene terephthalate) (CD‐PET)/metallocene isotactic polypropylene (m‐iPP) conjugated fibers
Authors: Shu Yao‐Chi , Hsiao Kai‐Jen
Published: September 2006

Cationic dyeable poly(ethylene terephthalate) (CD‐PET) and metallocene isotactic polypropylene (m‐iPP) polymers were extruded (in the proportions of 75/25, 50/50, 25/75) from two melt twin‐screw extruders to prepare CD‐PET/m‐iPP (and m‐iPP/CD‐PET)‐conjugated fibers of the island‐in‐sea type. This study investigated the thermal behavior and mechanical and morphological characteristics of the conjugated fibers using DSC, TGA, WAXD, melting viscosity rheometer, density indicator, tenacity measurement, and a polarizing microscope. Melting behavior of CD‐PET/m‐iPP polyblended polymers exhibited negative‐deviation blends (NDB) and the 50/50 blend showed a minimum value of the melt viscosity. Experimental results of the DSC indicated CD‐PET and m‐iPP molecules formed a partial miscible system. The tenacity of CD‐PET/m‐iPP‐conjugated fibers decreased initially and then increased as the m‐iPP content increased. Crystallinities and densities of CD‐PET/m‐iPP‐conjugated fibers presented a linear relation with the blend ratio. On the morphological observation, it was revealed that the blends were in a dispersed phase structure. In this study, the CD‐PET microfibers were successfully produced with enhanced diameters (from 2.2 to 2.5 μm). Additionally, m‐iPP colored fibers (m‐iPP fibers covered with CD‐PET polymer) were also successfully prepared. Meanwhile, the presence of PP‐graft‐MA compatibilizer improved the tenacity considerably. Blends with 10 wt % compatibilizer exhibited maximum improvement in the tenacity for m‐iPP colored fibers. The dye exhaustions of various fabrics followed the order: m‐iPP colored fibers > conventional CD‐PET fibers > CD‐PET microfibers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5396–5405, 2006
Modification of preparation method for polymer inclusion membrane (PIM) to produce hollow fiber PIM
Authors: Kusumocahyo Samuel P. , Kanamori Toshiyuki , Iwatsubo Takashi , Sumaru Kimio , Shinbo Toshio , Matsuyama Hideto , Teramoto Masaaki
Published: September 2006

A new preparation method for polymer inclusion membrane (PIM) was developed. The preparation method—called post‐treatment method—is very convenient to prepare a hollow fiber PIM. Using this method, a commercial cellulose triacetate (CTA) hollow fiber membrane can be easily converted into a hollow fiber PIM. Thus, a CTA hollow fiber membrane was allowed to swell in 2‐nitrophenyl‐n‐octyl ether (NPOE) in the presence of chloroform as a solvent for CTA and N,N,N′,N′‐tetraoctyl‐3‐oxapentane diamide (TODGA) as a carrier. After evaporating chloroform, a hollow fiber PIM containing NPOE and TODGA was obtained. The result of the transport experiment of cerium(III) ions using the hollow fiber PIM showed that cerium ions were effectively transported from the feed solution to the strip solution through the hollow fiber PIM, indicating that the hollow fiber PIM was successfully prepared using the post‐treatment method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4372–4377, 2006
Kinetic studies on free radical polymerization of acrylonitrile, initiated by chloramine‐T/hydrogen peroxide redox system
Authors: Mahadevaiah  , Demappa T.
Published: September 2006

The Kinetics of polymerization of Acrylonitrile initiated by chloramine‐T/H2O2 Redox System was studied in aqueous medium in the temperature range of 35–50°C. The effects of variations such as [Monomer], [CAT], [H2O2], temperature, and chloramine‐T disappearance (−Rm) were measured. The effect of some water‐ miscible organic solvents and surfactants on the rate of polymerization was investigated. The polymerization process is initiated by the free radical arising from oxidation of H2O2 by chloramine‐T and terminated by the mutual combination of the growing polymer radicals. Based on the kinetic results, a suitable reaction scheme is proposed and discussed for the various rates of polymerization and thermodynamic parameters were evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5877–5883, 2006
Preparation and characterization of polyurethane microcapsules containing n‐octadecane with styrene‐maleic anhydride as a surfactant by interfacial polycondensation
Authors: Su Jun‐Feng , Wang Li‐Xin , Ren Li , Huang Zhen , Meng Xian‐Wen
Published: September 2006

A series of polyurethane microcapsules containing a phase change material (PCM) of n‐octadecane was successfully synthesized by an interfacial polymerization in aqueous styrene‐maleic anhydride (SMA) dispersion with diethylene triamine (DETA) as a chain extender reacting with toluene‐2,4‐diisocyanate (TDI). The average diameter of microPCMs is in the range of 5–10 μm under the stirring speed of 3000–4000 rpm. Optical and SEM morphologies of microPCMs had ensured that the shell was regularly fabricated with the influence of SMA. FTIR results confirmed that the shell material was polyurethane and the SMA chains associated on core material reacted with TDI forming a part of shell material. The shell thickness was decreasing in the range of 0.31–0.55 μm with the molar ratio of DETA/TDI from 0.84 to 1.35 and the weight of core material increasing from 40 to 80% (wt %). By controlling the weight ratio of PCM as 40, 50, 60, 70, and 80% in microPCMs, it was found using DSC that the Tm and Tc of microPCMs were in the range of 29.8–31.0oC and 21.1–22.0°C and an obvious phase change had been achieved nearly the same temperature range of that of PCM. The results from release curves of microPCM samples prepared by 1.4, 1.7, and 2.0 g of SMA indicated the release properties were affected by the amount of the dispersant, which attributed to the emulsion effect and shell polymerization structure. The above results suggest that the shell structure of microPCMs can be controlled and the properties of microPCMs determined by shell will perform proper practical usage. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4996–5006, 2006
Synthesis of poly(vinyl butyral)s in homogeneous phase and their thermal properties
Authors: Fernández M. D. , Fernández M. J. , Hoces P.
Published: September 2006

The condensation reaction of butyraldehyde (BA) with poly(vinyl alcohol) (PVA) to give poly(vinyl butyral) (PVB) was studied in detail using N‐methyl‐2‐pyrrolidone (NMP) as solvent for PVA and PVBs. PVBs having various degrees of acetalization were obtained. The acetalization reaction under a variety of conditions gave at best a polymer with 97% acetalization. The extent of modification and the structure of the polymer, i.e., the ratio of acetal units from meso and racemic dyads of PVA, were determined by 1H‐NMR. The acetalization degree was reflected in the solubility of PVB; all products were soluble in NMP. PVBs were characterized by IR spectroscopy and 1H and 13C‐NMR. The glass transition temperatures of PVBs, determined by DSC, increased as vinyl alcohol units increased and displayed a positive departure from linearity. Thermal degradation of PVBs was studied using differential thermal analysis (DTA) and thermogravimetry (TGA) under dynamic conditions in nitrogen. The content of hydroxyl groups had an effect on the thermal stability of PVBs; the thermal stability of PVBs decreased as vinyl alcohol units increased. The apparent activation energy of the decomposition was determined by the Kissinger and Flynn–Wall methods, which agree well. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5007–5017, 2006
Structural effect of phenalkamines on adhesive viscoelastic and thermal properties of epoxy networks
Authors: Pathak Sandeep K. , Rao B. S.
Published: September 2006

Phenalkamine, the Mannich reaction products from cardanol, formaldehyde, and polyamines were prepared using ethylene diamine, diethylene triamine and triethlene tetraamine. These products were characterized by high‐pressure liquid chromatography (HPLC), infrared spectroscopy, and nuclear magnetic resonance spectroscopy (1H NMR). Clearly resolved peaks due to presence of triene, diene, monoene, and saturated side chain containing species of cardanol were observed in HPLC. The presence of characteristic methylene linkages of Mannich bases at δ 3.5–4.0 ppm was observed by 1H NMR. These curing agents were reacted with diglycidyl ether of bisphenol‐A at room temperature and the curing times were optimized. The cured resins showed good adhesion with different metal surfaces particularly higher values were observed with copper due to its high surface energy. The viscoelastic properties of the cured samples were determined by dynamic mechanical thermal analysis. The storage modulus (E′) was found to be in the order of 109 Pa and tan δ values are around 90°C. A reduction in storage modulus (E′) and an increase in tan δ values on postcuring were observed. Thermogravimetry analysis showed two‐stage degradation above 250°C for the cured samples. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4741–4748, 2006
Structure and dynamics of polyethylene/clay films
Authors: La Mantia F. P. , Dintcheva N. T. , Filippone G. , Acierno D.
Published: September 2006

The relationships between structure and rheology of polyethylene/clay hybrid composite blown films were investigated through rheological tests both in shear and elongational flow. Two polymer matrices (low density polyethylene, LDPE and linear low density polyethylene, LLDPE) with different relaxation kinetics were used. Independently from the matrix, morphological analyses (TEM, XRD, and SEM) indicate that the hybrid structures are similarly constituted of delaminated platelets or tactoids having a relevant degree of orientation along the draw direction. This strongly affects the rheological behavior of materials. However, despite the similarities emerged from morphological analyses, both shear (steady shear and oscillatory) and elongation measurements show a negligible effect upon the rheology of LDPE‐based nanohybrids. Conversely, relevant increases of shear viscosity, dynamic moduli and melt strength of LLDPE‐based nanohybrids have been detected. The effects of homopolymer relaxation kinetics have been investigated by means of stress relaxation tests. The results obtained seem to be consistent with the existence of a roughly bimodal population of dynamical species: a matrix component behaving like the homopolymer, and a fraction interacting with the filler, whose rheological behavior is controlled by the particles and their interactions with the polymer. Mechanical properties of hybrid films were also investigated. Differently from what happens in the melt state, the solid‐state properties mainly depend on the filler amount. The relative increases of tensile modulus and melt strength are of the same order of magnitude for both the matrices used, indirectly confirming the similarities in hybrids structures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4749–4758, 2006
Self‐curable system of an aqueous‐based polyurethane dispersion via a ring‐opening reaction of azetidine end groups
Authors: Wang Shih‐Chieh , Chen Po‐Cheng , Yeh Jen‐Taut , Chen Kan‐Nan
Published: September 2006

An azetidine (AZT) containing compound, 3‐azetidinyl propanol was synthesized from methyl acrylate with 3‐amino‐1‐propanol in a four‐step reaction. It was introduced into an isocyanate‐terminated carboxylic acid containing polyurethane (PU) prepolymer as the end group. A single‐component, AZT‐terminated self‐curable aqueous‐based PU dispersion was obtained from the water dispersion process after it was neutralized with triethylamine. Its carboxylic groups served not only as the internal emulsifier stabilizing the aqueous PU dispersion but also as PU self‐curing sites toward its AZT end groups via a ring‐opening reaction. The curing reaction took place on drying and resulted in polymeric network structure formation among the polymers. The performance properties of this self‐cured PU were evaluated in this study. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4383–4393, 2006
The use of experimental design to study the responses of continuous devulcanization processes
Authors: Sutanto P. , Picchioni F. , Janssen L. P. B. M.
Published: September 2006

This paper presents the use of statistical analysis for studying the responses of two continuous devulcanization processes (of the EPDM roofing sheet and the EPDM profile) in the extruder. The response is represented by the reaction conversion, which is denoted as the relative decrease in crosslink density. Experimental design is considered as a useful tool when the kinetic data for the physical modeling are not available. The models derived show similar tendency of both processes with respect to the temperature and the screw speed. A difference is observed in their responses to the feed rate, which might be the consequence of their different devulcanization rates. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5028–5038, 2006
A novel accelerator combination for the low temperature curing of silica‐filled NBR compounds
Authors: Palaty Shiny , Joseph Rani
Published: September 2006

Zinc salts of ethyl, isopropyl, and butyl xanthates were prepared in the laboratory. The effect of these xanthates in combination with zinc diethyldithiocarbamate (ZDC) on the vulcanization of silica‐filled NBR compounds has been studied at different temperatures. The cure times of these compounds were compared with that of NBR compounds containing tetramethylthiuram disulphide/dibenzthiazyl disulphide. The rubber compounds with the xanthates and ZDC were cured at various temperatures from 60 to 150°C. The sheets were molded and properties such as tensile strength, tear strength, crosslink density, elongation at break, compression set, abrasion resistance, flex resistance, heat buildup, etc. were evaluated. The properties showed that zinc salt of xanthate/ZDC combination has a positive synergistic effect on the cure rate and mechanical properties of NBR compounds. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5680–5683, 2006
Synthesis and characterization of waterborne polyurethane adhesives containing different amount of ionic groups (I)
Authors: Rahman Mohammad M. , Kim Han‐Do
Published: September 2006

A series of waterborne polyurethanes (WBPU) containing different amount of 2,2‐bis(hydroxymethyl) propionic acid (DMPA) were synthesized using prepolymer mixing process. Relationships between the DMPA content and physical, mechanical, and thermal properties as well as adhesive behavior at different condition were investigated. Stable aqueous dispersions of WBPU were obtained when the DMPA content was more than 10 mol %. At higher DMPA content, the particle size of the WBPU dispersion was lower but the viscosity of the dispersion was higher. Water swelling and tensile strength of the films increased with increasing of DMPA content. The optimum adhesive strength of WBPU adhesives was found to be depended on the DMPA content, pressing temperature, and pressure on adhesion process. The adhesive strength of WBPU adhesives increased with increasing DMPA content. The optimum pressing temperature decreased with increasing DMPA content. The adhesive strength of WBPU adhesives increased with increasing pressure up to 15 kg f/cm2 and then leveled off. The optimum pressing temperature of WBPU adhesives samples containing 24.02, 22.05, and 17.05 mol % DMPA was about 100, 120, and 140°C, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5684–5691, 2006
Effect of filler treatments on rheological behavior of calcium carbonate and talc‐filled polypropylene hybrid composites
Authors: Samsudin M. S. F. , Ishak Z. A. Mohd , Jikan S. S. , Ariff Z. M. , Ariffin A.
Published: September 2006

Commercial stearic acid treated calcium carbonate (CaCO3) was used to make a comparative study on rheological behavior of the CaCO3 and talc‐filled polypropylene (PP) hybrid composites with nontreated filler. Apparent shear viscosity and extrudate swell were investigated with variation of filler ratio and temperature with 30% by weight total of filler was used in PP composite. The Shimadzu capillary rheometer was used to evaluate shear viscosity and shear rate of the composite. It was found that the shear viscosities decrease with increasing shear rate. The apparent shear viscosity of the composite containing the stearic acid treated is slightly lower than untreated filler. Shear thickening behavior at higher shear rate has also shown by 15/15 treated composites at higher temperature about 220°C and investigation by SEM has proved that filler being densely packed at that condition. Treated composites also exhibit lower swelling ratio value than untreated composite, and swelling ratio also decreases linearly with increasing temperature and the die length–diameter ratio. It is believed that dispersion of filler play an important role not only on shear viscosity but also on swelling ratio of PP composite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5421–5426, 2006
Treatment of poly(styrene‐co‐methacrylic acid)/poly(4‐vinylpyridine) blends in solution under liquid–liquid phase‐separation conditions. A new method for phase‐separation data attainment from viscosity measurements
Authors: Torrens Francisco , Soria Vicente , Monzó Isidro S. , Abad Concepción , Campos Agustín
Published: September 2006

Phase diagrams are contributed for polymer mixture systems in solution. One polymer has proton‐acceptor character and the other has growing proton‐donor nature, which is reflected in the phase diagrams. Usually, these diagrams are obtained from size‐exclusion chromatographic (SEC) measurements. A totally novel application, which is exposed in this report, is the construction of the phase diagram from the viscometric experiments of polymer mixtures. The evaluated binodal or cloud‐point isotherms so built agree well with those from SEC. The results indicate an augmentation in the dimensions of donor polymer B, in the presence of acceptor polymer C, intensifying with the concentration of C, which is interpreted as an B‐C association growing as the number of hydrogen bonds increases. An increment in the Huggins constant for BC, as the proportion of methacrylic acid in the donor copolymer increases, means an augmentation in the interaction for BC, indicating an extension of compatibility. Viscometric experiments evidence hydrogen bonds, intensifying as greater proportion of donor groups has polymer B, equal to that observed in the phase diagrams. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5039–5049, 2006
Controlled release of diclofenac sodium and ibuprofen through beads of sodium alginate and hydroxy ethyl cellulose blends
Authors: Krishna Rao K. S. V. , Subha M. C. S. , Vijaya Kumar Naidu B. , Sairam M. , Mallikarjuna N. N. , Aminabhavi T. M.
Published: September 2006

Controlled release of diclofenac sodium (DS) and ibuprofen (IB) drugs through sodium alginate (NaAlg)‐hydroxy ethyl cellulose (HEC) blend polymeric beads has been investigated. Beads were prepared by precipitating the viscous solution of NaAlg and HEC blend in alcohol followed by crosslinking with calcium chloride. Different formulations were developed in bead form by varying the amount of HEC, crosslinking agent, and drug concentration. Swelling studies in water, percent encapsulation of drugs, and release studies were carried out. The DS‐loaded beads have shown better release performance than the IB‐loaded beads. Diffusion parameters were evaluated from the Fickian diffusion theory. Mathematical modeling studies and drug release characteristics through bead matrices were studied by solving Fick's diffusion equation. The results are discussed in terms of drug release patterns and theoretical concentration profiles generated through matrices, considering spherical geometry of the beads. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5708–5718, 2006
Influence of polymerization conditions on the viscosity of polyacrylamide via experimental design
Authors: Rosa Fátima , Bordado João , Casquilho Miguel
Published: September 2006

Polyacrylamide was synthesized by a free‐radical inverse emulsion technique and optimized via statistical experimental design, with the objective of developing a polymer with a high viscosity within this synthesis technique. The factors considered to affect the response variable, the viscosity of the polymer, were initiator (K2S2O8) concentration (c), reaction temperature (T), stirring rate (r), and initiator addition method (s, batch or dropwise). An experimental design of the four factors at two levels (24) was carried out to study the effect of these process variables on the viscosity of the polymer. The results show that the main factor having an effect on the viscosity was T, with smaller contributions from r and cs. The optimum combination of values for the factors yielding maximum viscosity was T = 65°C, c = 1 mM, r = 230 rpm, and s = dropwise addition. A close fit was obtained between the experimental and predicted values of the viscosity of the polymer solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5719–5724, 2006
Morphology and thermal properties of liquid crystal p‐PAEB/styrene copolymer
Authors: Gao Jungang , Wang Yong , Hou Guixiang
Published: September 2006

The homopolymer of unsaturated liquid crystal (LC) monomer for p‐phenylene di {4‐[2‐(allyloxy) ethoxy] benzoate} (p‐PAEB), and copolymer poly (p‐PAEB/St) of p‐PAEB with styrene (St) have been synthesized. The LC behavior and thermal properties of p‐PAEB and poly(p‐PAEB/St) have been studied by Polarizing Optical Microscopic (POM), Differential Scanning Calorimetry, X‐Ray Diffractometer (XRD), and Torsional Braid Analysis (TBA). The results demonstrate that LC phase texture and phase transition temperature of copolymers are affected by the composition of LC units in copolymers. The POM and XRD reveal that p‐PAEB has a smectic phase structure; the copolymer of p‐PAEB with styrene reveal deformed focal conics texture of smectic phase. The phase transition temperature range of p‐PAEB is 120.5–191.5°C, but the homopolymer of p‐PAEB has a broad LC temperature range from 77 to 170°C. The LC temperature range of poly(p‐PAEB/St) is broadened with increased content of p‐PAEB. The dynamic mechanical properties of LC polymer networks were investigated with TBA. The results indicate that the peak temperature of maximal mechanical loss is 114°C and is decreased with the addition of styrene © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5731–5736, 2006
Multiwavelength interferometry and competing optical methods for the thermal probing of thin polymeric films
Authors: Vourdas N. , Karadimos G. , Goustouridis D. , Gogolides E. , Boudouvis A. G. , Tortai J.‐H. , Beltsios K. , Raptis I.
Published: September 2006

Multiple‐wavelength interferometry (MWI), a new optical method for the thermal probing of thin polymer films, is introduced and explored. MWI is compared with two standard optical methods, single‐wavelength interferometry and spectroscopic ellipsometry, with regard to the detection of the glass transition temperature (Tg) of thin supported polymer films. Poly(methyl methacrylate) films are deposited by spin coating on Si and SiO2 substrates. MWI is also applied to the study of the effect of film thickness (25–600 nm) and polymer molecular weight (1.5 × 104 to 106) on Tg, the effect of film thickness on the coefficients of thermal expansion both below and above Tg, and the effect of deep UV exposure time on the thermal properties (glass transition and degradation temperatures) of the films. This further exploration of the MWI method provides substantial insights about intricate issues pertinent to the thermal behavior of thin polymer films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4764–4774, 2006
Preparation and application of an ultraviolet curable coating containing nanoscale α‐aluminum oxide
Authors: Chen Cheng‐Ho , Ou Ming‐Kun , Lin Shin‐Hsiang , Tsai Ming‐Shyong , Mao Ching‐Feng , Yen Fu‐Su
Published: September 2006

This study focuses on the preparation of an organic–inorganic ultraviolet (UV) curable coating containing the nanoscale α‐aluminum oxide (α‐Al2O3) powder and UV curable resin. This developed coating can form a protection film on the poly(vinyl chloride) (PVC) plastic tile surface. Thus, the abrasion resistance of the PVC plastic tile surface is improved. Besides, the adhesion between this UV cured film and the PVC plastic tile surface is well. After treatment with the UV curable coating that contains 6 wt % α‐Al2O3, the abrasion resistance of the PVC plastic tile surface can be improved up to 57%. From the result of a scanning electron microscopy (SEM) mapping photograph, it shows that the nanoscale α‐Al2O3 powder is well dispersed in the cured coating film. Under the wavelength of the visible light in the range of 400–800 nm, the degree of transparency for the coated film on poly(ethylene terephthalate) (PET) sheet is about 82–90%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5747–5752, 2006
Preparation and protein adsorption of hydrogel polysucrose microspheres
Authors: Hou Xin , Yang Jing , Huang Dongge , Wang Xiaoli , Yao Kangde
Published: September 2006

A series of novel hydrogel polysucrose microspheres with the mean size ranging from 200 to 500 μm were prepared via two‐step method. First, soluble polysucrose was synthesized by solution polymerization between sucrose and epichlorohydrin; second, a reversed phase suspension crosslinking reaction was performed to prepare polysucrose microspheres. The SEM images indicated that these spherical beads had smooth surface and hydrogel interior structure. FTIR was used to characterize the chemical structure of the beads. The hydrated and dry densities, equilibrium water content, and hydroxyl content of polysucrose microspheres were also investigated. The characteristic of high hydroxyl content (15.48–19.04 mmol/g) make these microspheres suitable for protein adsorption. Meanwhile, bovine serum albumin was used to examine the adsorption capacity of the microspheres. These microspheres had a capacity as high as 49.28 mg/g. The adsorption kinetics and recycling of the beads were also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5934–5940, 2006
Adsorption and desorption properties of grafted polyethylene films modified with polyethylenimine chains
Authors: Yamada Kazunori , Saitoh Yuji , Haga Yukiko , Matsuda Kiyomi , Hirata Mitsuo
Published: September 2006

The chelating membranes for adsorption of metal ions were prepared by the bonding of linear and branched polyethylenimines (LPEI and BPEI) on the glycidyl methacrylate (GMA) photografted porous polyethylene (pPE) (pPE‐g‐PGMA) films. The adsorption and desorption properties of LPEI and BPEI‐bonded pPE‐g‐PGMA (LPEI‐(pPE‐g‐PGMA) and (BPEI‐(pPE‐g‐PGMA)) films to Cu2+ ions were investigated as a function of the grafted amount, amount of bonded PEI, molecular mass of PEI, pH value, and temperature. The amounts of LPEI and BPEI bonded to the pPE‐g‐PGMA films increased over the reaction time, and the bonding of LPEI and BPEI offered the water‐absorptivity to the pPE‐g‐PGMA films. The amount of adsorbed Cu2+ ions at pH 5.0 had the maximum value at the grafted amount of 10 mmol/g for the (LDPEI‐(pPE‐g‐PGMA) and (BPEI‐(pPE‐g‐PGMA) films with a constant amount of bonded PEI. The amount of adsorbed Cu2+ ions for the LPEI‐(pPE‐g‐PGMA) films was higher than that for the BPEI‐(pPE‐g‐PGMA) films. The amount of Cu2+ ions desorbed from the LPEI‐(pPE‐g‐PGMA) and BPEI‐(pPE‐g‐PGMA) films increased with an increase in the HCl concentration. The quantities of Cu2+ ions of about 100% were desorbed in the aqueous HCl solutions of more than 0.1M for the LPEI‐(pPE‐g‐PGMA) films and more than 0.05M for the BPEI‐(pPE‐g‐PGMA) films. The amounts of adsorbed Cu2+ ions were almost the same in each adsorption process at pH 5.0. This indicates that the LPEI‐(pPE‐g‐PGMA) and BPEI‐(pPE‐g‐PGMA) films can be applied to a repeatedly generative chelating membrane for adsorption and desorption of metal ions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5965–5976, 2006
Performance evaluation of silane crosslinking of metallocene‐based polyethylene–octene elastomer
Authors: Zhang Guoqiang , Wang Genlin , Zhang Jun , Wei Ping , Jiang Pingkai
Published: September 2006

Vinyl trimethoxysilane (VTMS) was grafted onto metallocene‐based polyethylene–octene elastomer (POE) using a free‐radical reaction of VTMS and dicumyl peroxide as an initiator, and then the grafted POE was crosslinked in the presence of water. The effects of VTMS concentration on crystallization behavior, mechanical properties, and thermal properties of POE before and after crosslinking were studied in this article. Multiple melting behaviors were found for POE after silane crosslinking by using DSC measurement. Degree of crystallization of silane‐crosslinked POE decreases from 18.0 to 14.3%, with increase of VTMS from 0 to 2.0 phr. Tensile strength of silane‐crosslinked POE reaches a maximum of 28.4 MPa when concentration of VTMS is 1.5 phr, while elongation at break is 487%. TG shows that the temperature of 10% weight loss for pure POE is 405°C, while for crosslinked POE with addition of 2.0 phr VTMS the value comes to 452°C, indicating that crosslinking significantly help improve the thermal stability of POE. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5057–5061, 2006
Influence of processing conditions on dual‐phase continuous blend system of thermoplastic polyurethane with ethylene‐propylene‐diene monomer elastomer
Authors: Wu Lei , Luo Xin , Wang Xiaodong
Published: September 2006

In the present work, we extend the investigation on the influence of processing conditions on the morphology, the mechanical properties, and the rheology of the blends of thermoplastic polyurethane (TPU) and ethylene–propylene–diene monomer elastomer (EPDM). Scanning and transmission electron microscopies show that the dual‐phase continuous morphology of the blends was strongly dependant on the EPDM composition, processing temperature, and the shear rates. The network structure of the EPDM domain in TPU matrix became finest and most regular for the blends containing 7 wt % EPDM. It was also found that high shear rate favored the formation of the perfect network structure. Furthermore, the blends prepared at 180°C present finer and more perfect network structure than those at the other processing temperatures. The competition of compatible and incompatible segments of TPU with EPDM during melt blending plays an important role in development of the dual‐phase continuous morphology. This was reflected through the influence of processing conditions on the rheological properties, and was also verified by the Davies equation's prediction. The tensile properties present a significant improvement with addition of EPDM, and obtained the optimum value for the blends containing 7 wt % EPDM. The influence of different processing parameters on the mechanical properties is associated with their influence on the morphology, and better tensile properties are obtained in the processing conditions, in which, the finer and more perfect network structure of EPDM domain is presented. These facts confirm that the dual‐phase continuous morphology is the main advantage for higher tensile strength, elongation at break, and Young's modulus can be well controlled by different processing conditions for the improvement of mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5472–5482, 2006
Preparation and characterization of imidazole‐functionalized microspheres
Authors: Kim Hyungsoo , Daniels Eric S. , Dimonie Victoria L. , Klein Andrew
Published: September 2006

The preparation of imidazole‐functionalized latex microspheres by a two‐stage emulsion copolymerization process and their characterization are reported on. Emulsifier‐free emulsion copolymerization of styrene (St) and 1‐vinyl imidazole (VIMZ) exhibited bimodal particle size distributions caused by secondary homogeneous nucleation process. However, secondary nucleation can be avoided by using cetyltrimethylammonium bromide (CTAB) as a stabilizer at a concentration below its cmc (critical micelle concentration). This would result in the formation of monodisperse latex particles. The final particle size diameter depended on the concentration of CTAB as well as the amount of VIMZ. To control the amount of the functional imidazole groups on the latex particle surfaces, independent of the latex diameters, without secondary nucleation of particles, the seeded emulsion copolymerization of styrene and VIMZ was explored as a second‐stage polymerization at different concentrations and ratios of monomers in the presence of the previously prepared monodisperse poly(styrene‐co‐1‐vinyl imidazole) seed latex particles. The concentration of imidazole functional groups on the surface of the latex particles could also be varied through the rearrangement of hydrophilic imidazole groups by varying the second‐stage monomer addition process such as the utilization of monomer‐swollen seed particles or a shot addition of monomers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 120:5753–5762, 2006
Removal of nitrite ions from aqueous solutions by poly(N,N‐dimethylamino ethylmethacrylate) hydrogels
Authors: Yılmaz Z. , Akkaş P. Kavakli , Şen M. , Güven O.
Published: September 2006

Removal of nitrite ions from aqueous solutions by protonated poly(N,N‐dimethylamino ethylmethacrylate) hydrogels (P(DMAEMA)) was investigated. We have shown that polycationic and pendant secondary amine group containing P(DMAEMA) hydogels is very efficient and highly selective for the removal of nitrite ions from aqueous solutions at even in very high concentrations. Adsorption studies have shown that pH of the nitrite solution has influence on the nitrite ion uptake capacity of P(DMAEMA) hydrogels. The adsorption capacity of hydrogels had been increased up to 3100 mg NO/g dry gel, by changing pH of the solution. The results of the adsorption studies showed that the interaction between nitrite ions and quaternized amine groups agree with the Langmuir‐type isotherm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6023–6027, 2006
Dynamic crystallization of polypropylene and wood‐based composites
Authors: Bouza R. , Marco C. , Martín Z. , Gómez M. A. , Ellis G. , Barral L.
Published: September 2006

Thermoplastic composites made of an isotactic polypropylene (iPP) matrix and woodflour (WF) were prepared by melt‐blending, using twin‐screw extrusion and injection molding. Up to 20 wt % of the composite was composed of WF. The incorporation of an interfacial agent made of an ethylene/methacrylic acid copolymer to iPP and WF, PP/WF, binary blends causes a compatibilization effect that becomes evident due to a reduction in the crystallization temperature of PP. In both the binary composites and the compatibilized or ternary composites, the PP adopts an α or monoclinic structure when crystallization occurs from the melt under dynamic conditions at cooling rates between 1 and 20°C min−1. On the other hand, X‐ray diffraction analysis using synchrotron radiation of the injection‐molded samples demonstrates the existence of a β or trigonal form in the binary as well as the ternary PP/WF composites. They reach kβ levels between 0.18 and 0.25, which can be interpreted as the co‐operation between a reduction of the crystallization rate and the shear effect induced during the injection. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6028–6036, 2006
Finite volume method as the numerical method for new emulsion polymerization tubular reactor with internal angle baffles
Authors: Mendoza Marín Florentino L. , Maria Ferrareso Lona Liliane , Wolf Maciel Maria R. , Maciel Filho Rubens
Published: September 2006

A finite volume method is used to solve a determinist mathematical model and to analyze the performance of an alternative design for an emulsion polymerization reactor with internal angular baffles as static mixer. It is assumed to be a steady‐state, cylindrical one‐dimensional model having a fully developed laminar plug flow. The Smith‐Ewart model is used to estimate the monomer conversion, the kinetics is of Arrhenius type, and laminar finite‐rate model is assumed to compute chemical source terms. The objective of this work is to develop the finite volume method for the new emulsion polymerization tubular reactor with internal angle baffles. The performance of the alternative reactor is compared with continuous tubular reactor with constant reaction temperature. The simulations were validated with experimental results for the isothermal and tubular reactor, with a good concordance. The results with baffles were better than without baffles in relation to desired properties such as particle size and viscosity. The problem is sufficiently well solved by finite volume method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6037–6048, 2006