bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of antimicrobial polypropylene sutures by graft copolymerization. II. Evaluation of physical properties, drug release, and antimicrobial activity
Authors: Gupta Bhuvanesh , Anjum Nishat , Gulrez S. K. H. , Singh Harpal
Published: December 2006

Polypropylene (PP) sutures are prepared by the simultaneous radiation grafting of 1‐vinylimidazole (VIm) onto PP monofilament sutures. The tenacity slightly decreases whereas the elongation increases with the increase in the degree of grafting. Thermogravimetric analysis shows that the stability of the sutures is enhanced by the grafting process. The grafted sutures have reasonably good water uptake. They are subsequently immobilized with an antimicrobial drug, ciprofloxacin. The modified suture releases the drug over a period of 4–5 days. The antimicrobial activity of the modified suture is determined against Esherichia coli by the zone of inhibition technique. A clear zone of inhibition is observed around the drug‐containing suture. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3534–3538, 2007
Elastic properties of adhesive polymers. I. Polymer films by means of electronic speckle pattern interferometry
Authors: Konnerth Johannes , Gindl Wolfgang , Müller Ulrich
Published: December 2006

The elastic modulus and Poisson's ratio of seven different polymers frequently used as wood adhesives and/or matrix polymers in wood‐ and natural‐fibre‐reinforced composites, respectively, were determined by means of tensile tests. Specimen deformation during testing was measured by means of a mechanical extensometer and an electronic speckle pattern interferometry system, respectively. The results from both methods show an excellent correlation for the elastic modulus. The elastic moduli of the studied polymers cover a wide range from 0.47 GPa for polyurethane to 6.3 GPa for melamine–urea–formaldehyde, whereas Poisson's ratios show less variability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3936–3939, 2007
Polymerization of diisopropyl fumarate under microwave irradiation
Authors: Susana Cortizo M.
Published: December 2006

Diisopropyl fumarate (DiPF), a representative monomer of dialkyl fumarates, was polymerized by microwave irradiation at three different powers (140, 210, and 280 W), using a domestic microwave oven. The nature and concentration of initiators [2,2′‐azobisisobutyronitrile (AIBN) and benzoyl peroxide (BP)], power and energy of microwave irradiation on the conversion, weight average molecular weight (Mw), and polydispersity index (Mw/Mn) were analyzed. The results indicate that the microwave conditions have a significant nonthermal effect in enhancing the polymerization rate of DiPF. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3785–3791, 2007
Synthesis of succinylated poly(4‐hydroxystyrene) and its application for negative‐tone photoresist
Authors: Cho Hyejin , Kim Junyoung , Patil Prashant , Kim Jun Young , Kim Tae‐Ho
Published: December 2006

Atom transfer radical polymerization (ATRP) was used to prepare poly(acetoxystyrene) (PAS) with a controlled molecular weight and narrow polydispersity. Using 1‐phenylethylbromide (PEBr)/CuBr/Cu(0)/2,2′‐bipyridine as an initiating system, the heterogeneous ATRP of 4‐acetoxystyrene was carried out to form PAS as a precursor polymer. The reaction follows the first‐order kinetics with respect to the conversion of monomer. A linear molecular weight (polydispersities Mw/Mn = 1.07–1.27) indicates the “living”/controlled nature of polymerization. The obtained PAS was chemically modified to obtain succinylated poly(hydroxystyrene) (Succ‐PHS). The formulation of Succ‐PHS, crosslinker (benzoguanamine‐formaldehyde), and triphenylsulfonium triflate (TPST) as a photo acid generator (PAG) was carried out by UV irradiation using an i‐line tool. The performance of the resultant polymer as the negative resist pattern photoresist for photolithography was studied with instrumental techniques. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3560–3566, 2007
Phase inversion of polyacrylamide‐based inverse‐emulsions: Influence of inverting‐surfactant type and concentration
Authors: Armanet Luc , Hunkeler David
Published: December 2006

The phase inversion of polymeric water‐in‐oil emulsions has been systematically studied by employing nonylphenol and alcohol ethoxylates with various chemistries as well as physical chemical characteristics. A combination of thermodynamics, phase diagrams, and rheometry were used to investigate the behavior of the inverting surfactants as well as the inverted, acrylamide‐based, cationic emulsions. Polymeric inverse‐emulsions containing the inverting surfactant showed no evidence of low‐shear thinning, though they did thin as hydrodynamic forces increased (0.01 to 100 s−1) prior to reaching a chemistry‐ and concentration‐independent plateau, as is typical for emulsions. The viscosity of emulsions containing inverting surfactants reached a minimum at 1.2% of the “emulsion breaker”. The efficiency of inversion was optimized at 2 wt % of nonylphenols, expressed as a percentage of the total emulsion mass, and increased with the degree of ethoxylation. Interestingly, the viscosity of the polymer inverted in water was maximized at an inverting‐surfactant level corresponding to the CMC of the pure surfactant in water. The alcohol ethoxylates required a higher concentration for inversion (3 wt %), though they provided a higher ultimate inverse viscosity of the polymeric emulsion in water. Therefore, while the inversion process was less efficient with alcohol ethoxylates, the ultimate dilution solution properties of the polyelectrolytes liberated were improved relative to the nonylphenols. Overall, the process of adding a water‐in‐oil emulsion, containing an emulsion breaker, to an excess of water involves a catastrophic inversion mechanism. To be effective under such circumstances, an inverting surfactant should have a partition coefficient between the aqueous an organic phases greatly exceeding unity as well as a hydrophilic–lipophilic balance (HLB) above 12. Effectiveness increases linearly with the partition coefficient. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3567–3584, 2007
Effect of silane coupling agents on the properties of pine fibers/polypropylene composites
Authors: Gironès Jordi , Méndez José Alberto , Boufi Sami , Vilaseca Fabiola , Mutjé Pere
Published: December 2006

In the present work, PP‐based composites, reinforced with surface modified pine fibers, have been prepared. The surface of the fibers has been treated with several silane derivatives bearing specific functionalities. NH2, SH, long aliphatic chain, and methacrylic group were chosen as functionalities of the silane derivatives for evaluating the compatibility with the polymer matrix. Mechanical analysis, contact angle and XPS spectra, SEM microscopy, and water uptake measurements were used as characterization techniques for evaluating the nature of composites. XPS as well as contact angle measurements demonstrated that pine fibers and silane derivatives were effectively coupled. The mechanical analysis showed an increase in Young's and flexural moduli, by 12% and 130% respectively, and nonsignificant changes in the ultimate tensile strength were noted after surface modification. Water uptake measurements revealed a low water absorption by the materials, always lower than 2 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3706–3717, 2007
Effects of surface modification, carbon nanofiber concentration, and dispersion time on the mechanical properties of carbon‐nanofiber–polycarbonate composites
Authors: Gao Yong , He Peng , Lian Jie , Schulz Mark J. , Zhao Jiang , Wang Wei , Wang Xiaqin , Zhang Jing , Zhou Xingping , Shi Donglu
Published: December 2006

The time effect of ultrasonication was investigated for dispersing carbon nanofibers (CNFs) into a polycarbonate (PC) matrix on the mechanical properties of thus‐produced composites. The effects of CNF surface modification by plasma treatment and the CNF concentration in composites on their mechanical properties were also explored. The plasma coating was characterized by HRTEM and FT‐IR. Furthermore, the plasma polymerization (10 w) treatment on the CNF enhanced the CNF dispersion in the polymer matrix. The mechanical properties of the CNF–PC composites varied with the dispersion time, at first increasing to a maximum value and then dropping down. After a long ultrasonic treatment (24 h), the properties increased again. At a high concentration, the CNF‐PC suspension became difficult to disperse. Additionally, the possible mechanisms for these behaviors are simply proposed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3792–3797, 2007
Synthesis and characterization of a novel biodegradable polymer poly(lactic acid–glycolic acid‐4‐hydroxyproline)
Authors: Duan Jiufang , Du Jie , Zheng Yubin
Published: December 2006

The effect of certain preparative variables, such as the composition of the feeds, the reaction time, catalyst concentration, degrees Centigrade (°C), and the reaction temperature on the properties of prepared polymer poly(lactic acid–glycolic acid‐4‐hydroxyproline) (PLGA‐Hpr), was investigated via direct melt polymerization with stannous chloride as a catalyst activated by a proton acid. The new polymer had pendant amine functional groups along the polymer backbone chain. The results with regard to the inherent viscosity and yield of PLGA‐Hpr are discussed in relation to a recently proposed polymerization mechanism. The content of lactic acid, glycolic acid, and 4‐hydroxyproline (Hpr) in the copolymer was found to affect the surface and bulk hydrophilicity of various PLGA‐Hpr copolymers. The inherent viscosity of the copolymer and the yield of the reaction depended on the reaction temperature and varied with the reaction time. The higher the 4‐hydroxyproline content of the feedzaq, the lower the inherent viscosity of the copolymer and the yield of the reaction. When the glycolic acid content was more than 70% or the content of HPr was more than 10%, the polymer changed from hemicrystalline to amorphous. The in vitro degradation rate of the PLGA‐HPr copolymers is dependent on the feed ratios of lactic acid and glycolic acid in the polymer chain. Lactic acid‐rich polymers are more hydrophobic; subsequently they degrade more slowly. The structure of this polymer was verified by infrared (IR) spectroscopy, proton nuclear magnetic resonance (1H‐NMR) spectroscopy, X‐ray diffractometry (XRD), and differential scanning calorimetry (DSC). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3585–3590, 2007
Electrocopolymerization of a binary mixture of pyrrole and 2‐amino‐4‐phenylthiazole: Kinetic studies, copolymer structure, and applications as corrosion protection for mild steel in acid medium
Authors: Sayyah S. M. , El‐Deeb M. M.
Published: December 2006

Electrochemical copolymerization of a binary mixture of pyrrole and 2‐amino‐4‐phenylthiazole on platinum electrode in acid medium was carried out. The kinetic parameters were calculated using ex situ microgravimetric and electrochemical data. The experimentally obtained kinetic equations were RP,W = kW [acid]1.16 [monomer]1.85 from microgravimetric data and RP,E = kE [acid]1.1 [monomer]1.9 from the values of the anodic current density using cyclic voltammetry technique. The apparent activation energy was calculated by the two techniques and is found to be 32.55 and 29.6 kJ/mol from microgravimetric and electrochemical data respectively. The monomer reactivity ratios (r1 and r2) were calculated according to Fineman–Ross method and the copolymer structure was determined from the obtained data, which is found to be a block copolymer structure. The applications of the prepared copolymer as corrosion protection of mild steel in acid medium are studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4047–4058, 2007
Control over wettability of textured surfaces by electrospray deposition
Authors: Mizukoshi Tomoya , Matsumoto Hidetoshi , Minagawa Mie , Tanioka Akihiko
Published: December 2006

Microtextured surfaces were prepared by electrospray deposition (ESD) from hydrophilic and hydrophobic acrylic resin solutions. The surface morphologies and topologies were characterized using scanning electron microscopy and laser profile microscopy, respectively. Wetting behaviors on the surfaces were characterized by contact angle and sliding angle measurements. The contact angle of the water droplet on the hydrophilic resin‐coated surfaces decreased with an increase in the surface roughness. On the other hand, the contact angle on the hydrophobic resin‐coated surfaces increased with an increase in the surface roughness. In addition, a patterned surface composed of aligned fibers by ESD showed anisotropy of both wetting and sliding behaviors. These results indicate that ESD is a useful method for designing a textured surfaces and controlling the surface wettability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3811–3817, 2007
Enzymatic oxidation of alkoxyanilines for preparation of conducting polymers
Authors: Nabid Mohammad Reza , Sedghi Roya , Entezami Ali Akbar
Published: December 2006

A biomimetic route for synthesis of a conducting molecular complex between polyalkoxyanilines and a polyelectrolyte, poly (sodium 4‐styrenesulfonate) (SPS) is presented. Horseradish peroxidase (HRP) was used to catalyze the polymerization of alkoxyanilines. A few of water‐soluble ring‐substituted polyalkoxyanilines have been enzymatically synthesized with variation of groups, such as ortho‐methoxy, meta‐methoxy, ortho‐ethoxy, and meta‐ethoxy to form polyalkoxyanilines/SPS complexes. The presence of alkoxy substituents affects the polymerization reactions. These enzymatic oxidation reactions occur in a different potential range to that observed for the chemical polymerization. Similar electrochemical and optical properties were obtained for every pair of ortho‐ and meta‐alkoxy substituted polyanilines. For comparing, polyalkoxyanilines were also prepared by chemical polymerization in the presence of SPS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 103: 3724–3729, 2007
Cation exchange finishing of nonwoven polyester with polycarboxylic acids and cyclodextrins
Authors: Ducoroy L. , Martel B. , Bacquet M. , Morcellet M.
Published: December 2006

We describe a chemical method for the finishing of polyester nonwoven fabrics that aimed to obtain ion exchange textiles. This approach was based on the use of polycarboxylic acids (PCA) and cyclodextrins as carbohydrate compounds and finishing agents, respectively. It was observed that the reaction between these reactants yielded a crosslinked polymer that was physically anchored onto the fibers. This polymer can be considered as a resin issued from the esterification between the COOH groups of the PCA with the OH groups of the carbohydrate. As the esterification reaction was not complete, many free carboxylic groups remained on the surface of the coating polymer. This feature offered the ion exchange properties to the textile support. In this article, we described the pad‐dry‐cure process and showed the influence of the curing parameters (time and temperature), the nature, and the concentration of the components and the pH of the impregnating bath. The grafting rate (in wt %) and the ion exchange capacity (IEC) were observed in parallel. First, it was observed that the best IEC capacity (that could reach 1 mmol/g) was obtained when an ideal compromise was applied between time and temperature of curing. We also evidenced that IEC depended on the nature and on the concentration of the PCA (chosen among citric acid, 1,2,3,4‐butanetetracarboxylic acid, and polyacrylic acid) and on the pH of the impregnating bath. Finally, it was observed that cyclodextrins were more appropriate than starch as finishing coreactants. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3730–3738, 2007
Silica nanoparticles modified with vinyltriethoxysilane and their copolymerization with N,N′‐bismaleimide‐4,4′‐diphenylmethane
Authors: Su Heng‐Lei , Hsu Jung‐Mu , Pan Jing‐Pin , Chern Chorng‐Shyan
Published: December 2006

The synthesis and characterization of the vinyltriethoxysilane‐modified silica nanoparticles were investigated. It was shown that the vinyltriethoxysilane molecules had been successfully grafted onto the silica nanoparticles. The native and silane‐modified silica dispersions in N‐methyl‐2‐pyrrolidone with the total solids contents within the range 1–6 wt % exhibited dramatically different flow behaviors. The polymerization of N,N′‐bismaleimide‐4,4′‐diphenylmethane (BMI) initiated by barbituric acid in the presence of the native or vinyltriethoxysilane‐modified silica nanoparticles were then carried out in γ‐butyrolactone (total solids content = 20%). The higher the level of silica, the better the thermal stability of the BMI/silane/silica composite particles. The silane‐modified silica particles significantly improved their dispersion capability within the continuous BMI oligomer matrix. Furthermore, the degree of dispersion of the vinyltriethoxysilane‐modified silica particles in the BMI oligomer matrix decreased with the weight percentage of silica based on total solids increased from 20 to 40 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: Sci 103: 3600–3608, 2007
Effect of spinning speed on the structure and physical properties of filament yarns produced from used PET bottles
Authors: Abbasi M. , Mojtahedi M. R. M. , Khosroshahi A.
Published: December 2006

In the previous work (S. Kiantash, MS Thesis, Amirkabir University of Technology, Textile Engineering Department, Tehran, Iran, 2002), the possibility of producing filament yarns from used PET bottles was investigated and the production was successfully carried out. To improve physical properties and to have a detailed understanding of the molecular structure, spinning variables such as the take‐up speed (one of the most influencing factors) should be varied and studied. In the present work, continuous filament yarns from virgin PET chips and used PET bottles were produced at the two take‐up speeds of 2500 and 3000 m/min. Optical birefringence, crystallinity (obtained from three methods including density, calorimetry, and FTIR), tenacity, breaking elongation, initial modulus, and shrinkage of yarns were measured and compared. Optical birefringence and crystallinity (obtained from all three methods) of used samples show higher values compared with those of virgin samples produced at both take‐up speeds. Consequently, the tenacity of used samples is higher and breaking elongation is lower. Generally, samples having bigger crystallinity present higher initial modulus and smaller shrinkage. However, results of initial modulus and shrinkage do not correspond to this assumption. As it was predicted, increasing the take‐up speed resulted in an increase in the optical birefringence, crystallinity, tenacity, and initial modulus and a reduction in the breaking elongation of both virgin and used samples. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3972–3975, 2007
Effect of solvent exchange on the pore structure and dissolution behavior of cellulose
Authors: Ishii D. , Kanazawa Y. , Tatsumi D. , Matsumoto T.
Published: December 2006

Effect of solvent exchange, i.e., the sequential immersion in water, acetone, and DMAc on the pore structure of cellulose and its dissolution behavior in lithium chloride/N,N‐dimethylacetamide (LiCl/DMAc) was investigated by using size exclusion liquid chromatography (SEC), dynamic light scattering (DLS), and small‐angle X‐ray scattering (SAXS). In the SEC experiment, poly(styrene)s, diethyl phthalate, and acetone were used as probe solutes and 2‐butanone was used as an eluent. Capacity factor of these solutes in the solvent‐exchanged cellulose were larger than those in the untreated one. This was remarkable when diethyl phthalate and acetone were used as solutes. Since the molecular radii of these solutes were estimated to be less than 1 nm, it was shown that the solvent exchange increases the amount of pores within cellulose with the radii of less than 1 nm. In the SAXS experiment, structural difference between the solvent exchanged and the untreated celluloses was observed when the celluloses were immersed in acetone. Values of specific inner surface and average chord length calculated from SAXS profile showed that the amount of small pores was increased in the solvent exchanged cellulose. Considering the results from SEC, DLS, and SAXS measurements, facilitated dissolution of the solvent exchanged cellulose in LiCl/DMAc was attributed to the increase in the pores with the radii of less than 1 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3976–3984, 2007
Modification of polyester fabric properties by surfactant‐aided surface polymerization
Authors: Siriviriyanun Ampornphan , O'Rear Edgar A. , Yanumet Nantaya
Published: December 2006

Poly(methyl methacrylate) (PMMA) was applied to polyester fabric using a surface analog of emulsion polymerization. The admicellar polymerization was carried out using 1.5 mM dodecylbenzenesulfonic acid (DBSA) at pH 4 with 0.15M NaCl, 1 : 8 DBSA:monomer, and 1 : 10 initiator:monomer molar ratio. The PMMA film, which was formed, was characterized by SEM and FTIR. Hydrolysis of the PMMA film on polyester fabric was carried out to introduce carboxylic acid groups to the polyester surface to increase its hydrophilicity. The results show that a PMMA thin film was successfully formed on the polyester fabric. The water contact angle of the PMMA‐coated polyester fabric after hydrolysis by 10M H2SO4 for 5 h was reduced from 117.3° to 0° and there was a significant increase in the moisture‐regain value of the treated fabric. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4059–4064, 2007
Surface and pore structure modification of cellulose fibers through cellulase treatment
Authors: Park Sunkyu , Venditti Richard A. , Abrecht David G. , Jameel Hasan , Pawlak Joel J. , Lee Jung M.
Published: December 2006

The surface and pore structure of cellulose fibers have a significant impact on the properties and performance in applications. Cellulase enzymatic hydrolysis of cellulose fibers can result in changes to the surface and pore structure, thus providing a useful tool for fiber modification. This research characterizes these changes using various test methods such as fiber dimension, water retention value (WRV), hard‐to‐remove (HR) water content, freezing and nonfreezing bound water content, polymer adsorption, and crystallinity index. For a high‐dosage cellulase treatment (600 U/g dry solid), the fiber length was significantly decreased and the fibers were “cut” in the cross direction, not in the axial direction. The swelling capacities as measured by the WRV and HR water content increased for the high‐dosage treatment. Three independent measurements (nonfreezing bound water, polymer adsorption, and crystallinity index) are in good agreement with the statement that the amorphous regions of cellulose fibers are a more readily available substrate relative to crystalline regions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3833–3839, 2007
Comparative effects of cobalt carboxylates on the thermo‐oxidative degradation of LDPE films
Authors: Roy P. K. , Surekha P. , Rajagopal C. , Choudhary V.
Published: December 2006

This article reports the effect of three cobalt carboxylates—cobalt stearate (CoSt3), cobalt palmitate (CoPal3), and cobalt laurate (CoLau3)—on the thermo‐oxidative degradation of low‐density polyethylene (LDPE) films prepared by sheeting process. The carboxylates were blended with LDPE in the concentration range of 0.05–0.2% (w/w). The degradation was monitored by techniques such as FTIR spectroscopy, change in the mechanical properties (tensile strength and elongation at break), viscometry, surface electron microscopy, melt flow index measurements, and apparent density measurements. Studies indicate that films containing these additives are highly susceptible to thermo‐oxidative degradation. Oxygen containing functionalities such as carbonyl and vinyl species are generated on the surface of polyethylene because of thermo‐oxidation, as indicated by FTIR studies. This oxidative process is accelerated in the presence of cobalt carboxylates. The degradation of LDPE was found to increase proportionally with concentration as well as with increasing chain length of the cobalt carboxylate, and follow the order CoSt3 > CoPal3 > CoLau3. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3758–3765, 2007
Electrospinning of high‐molecule PEO solution
Authors: Wan Yu‐Qin , He Ji‐Huan , Yu Jian‐Yong , Wu Yue
Published: December 2006

Electrospinning is a simple but powerful method for making nanofibers that can then be collected to create porous mats. We expand the range of this technique by making nanofibers from macromolecules with a molecular weight of 3,000,000, namely poly(ethylene oxide) (PEO). Gelation of PEO blocks its spinning by traditional electrospinning. PEO was mixed with pure alcohol, and in specific concentration 10 wt % and under vibration condition, the mixed solution behaves like polymers for electrospinning, the average diameter of the obtained nanofibers is about 100 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3840–3843, 2007
Microbiocidal activity of chitosan‐N‐2‐hydroxypropyl trimethyl ammonium chloride
Authors: Chi Weilin , Qin Caiqin , Zeng Lintao , Li Wei , Wang Wei
Published: December 2006

Chitosan‐N‐2‐hydroxypropyl trimethyl ammonium chloride (QTS) was prepared by reaction of chitosan with glycidyl trimethylammonium chloride, which was characterized by FTIR. QTS with different molecular weights (Mw 41.55 × 104, 9.02 × 104, 3.57 × 104, and 0.17 × 104) showed biocidal activity on Staphylococcua aureus, Bacillus subtilis, Staphylococcua epidermidis, and Candida albicans. QTS with high molecular weight had high biocidal activity on the gram‐positive bacteria, and the biocidal effect of QTS decreased with decreasing molecular weight from 9.02 × 104 to 0.17 × 104. QTS with Mw 41.55 × 104 exhibits slightly lower biocidal activity on Candida albicans than other QTS samples. However, no remarkable biocidal activity of QTS was found on gram‐negative bacteria Escherichia coli and Pseudomonas aeruginosa at the concentration up to 10 g L−1. Existence of cationic surfactant, amphoteric surfactant, nonionic surfactant, Ca2+ and Mg2+ had no remarkable effect on microbiocidal activity of these QTS samples. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3851–3856, 2007
Synthesis of organic–inorganic hybrid polymeric nanocomposites for the hard coat application
Authors: Hsiao Shu Chuan , Chiang Hau‐Chun , Chien‐Chao Tsiang Raymond , Liu Ta‐Jo , Wu Jeng‐Jaw
Published: December 2006

An organic–inorganic hybrid polymeric nanocomposite has been synthesized for making UV‐curable hard coats. This nanocomposite consists of nano‐sized colloidal silica functionalized with vinyltriethoxysilane (VTES) and dendritic acrylic oligomers (DAO) which have been formed earlier via a reaction of ethylenediamine (EDA) with trimethylopropane triacrylate (TMPTA). Applied as a hard coat on top of a polyethylene terephthalate (PET) film, this nanocomposite has a short UV‐cure time and the cured coat has an enhanced thermal decomposition temperature (Td), 89–90% transparency, increased hardness up to 3H, better adhesion up to 4B, and a flat surface with a root mean square roughness of 2–4 nm. The preparation as well as the characterization of the constituting species and the final hybrid are described in detail. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3985–3993, 2007
Preparation and characterization of poly(vinyl chloride)/virgin and treated sisal fiber composites
Authors: Djidjelli Hocine , Boukerrou A. , Founas R. , Rabouhi A. , Kaci M. , Farenc J. , Martinez‐Vega Juan‐Jorge , Benachour Djafer
Published: December 2006

Mechanical property changes, thermal stability, and water absorption capacity of poly(vinyl chloride) (PVC)/sisal fiber composites were assessed with respect to the effect of maleic anhydride chemical treatments of the sisal fiber, for five different sisal fiber contents, varying from 0 to 30% by weight in the composite. The composites prepared with the untreated sisal exhibited higher tensile modulus and hardness than the unloaded resin, while elongation and tensile strength were reduced. The deterioration in the mechanical properties of PVC blended with sisal fiber is attributed to the presence of moisture, interfacial defects at the fiber and polymer interface, and fiber dispersion in the PVC matrix. The amount of absorbed water is a function of the amount of fiber in the composite (F0 = 0 phr, F5 = 0.77 phr, and F20 = 4.83 phr). The comparison of the results of characterization of F5, F20, and F30 formulations prepared with the untreated fibers and the treated ones showed a reduction in absorbed water after the chemical treatment of fiber with maleic anhydride (F0 = 0 phr, F5 = 0.28 phr, and F20 = 2.99 phr), thus improving the mechanical properties of composites prepared with the treated sisal. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3630–3636, 2007
Melt transesterification of bisphenol acetophenone–polycarbonate: A kinetic study
Authors: Godinez C. , Lozano L. J.
Published: December 2006

This article deals with the development of kinetic parameters for bisphenol acetophenone–polycarbonate made by melt transesterification with diphenyl carbonate. The understanding of the influence of borosilicate glass of the reactor construction materials on the accuracy of the kinetic data is reported. During the development of analytical methods, the use of high performance liquid chromatography‐mass spectrometry (HPLC‐MS) was proven to be a valid tool to determine the oligomers existing in the reaction mixture. Accurate kinetics parameters were obtained by elimination of the interference of the construction materials. We provide the rate expressions, kinetic parameters [forward reaction frequency factor = 2.456 × 1013 ± 0.01 (cm3/mol)2/min, forward reaction activation energy = 45.69 ± 0.2 kJ/mol, reverse reaction frequency factor = 2.068 × 1014 ± 0.01 (cm3/mol)2/min, and reverse reaction activation energy = 56.37 ± 0.1 kJ/mol], and equilibrium constants at various temperatures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4072–4079, 2007
Preparation of rubber composites from ground tire rubber reinforced with waste‐tire fiber through mechanical milling
Authors: Zhang Xin‐Xing , Lu Can‐Hui , Liang Mei
Published: December 2006

Composites made from ground tire rubber (GTR) and waste fiber produced in tire reclamation were prepared by mechanical milling. The effects of the fiber content, pan milling, and fiber orientation on the mechanical properties of the composites were investigated. The results showed that the stress‐induced mechanochemical devulcanization of waste rubber and the reinforcement of devulcanized waste rubber with waste‐tire fibers could be achieved through comilling. For a comilled system, the tensile strength and elongation at break of revulcanized GTR/fiber composites reached maximum values of 9.6 MPa and 215.9%, respectively, with 5 wt % fiber. Compared with those of a composite prepared in a conventional mixing manner, the mechanical properties were greatly improved by comilling. Oxygen‐containing groups on the surface of GTR particles, which were produced during pan milling, increased interfacial interactions between GTR and waste fibers. The fiber‐filled composites showed anisotropy in the stress–strain properties because of preferential orientation of the short fibers along the roll‐milling direction (longitudinal), and the adhesion between the fiber and rubber matrix was improved by the comilling of the fiber with waste rubber. The proposed process provides an economical and ecologically sound method for tire‐rubber recycling. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4087–4094, 2007
Preparation and properties of polysulfone–clay composite membranes
Authors: Monticelli Orietta , Bottino Aldo , Scandale Ivan , Capannelli Gustavo , Russo Saverio
Published: December 2006

Porous membranes and dense films were prepared from polysulfone solutions in N‐methyl‐2‐pyrrolidone (NMP) containing different types and amounts of clay. Commercial clays supplied by Southern Clay, either unmodified (Cloisite Na) or organically modified (Cloisite 30B and Cloisite 93A), were used. The clay behavior in the organic solvent was dependent on the presence and type of the organic compatibilizer: Cloisite containing Na ions did not swell in NMP, whereas those with the organic compatibilizer swelled, though to a different degree. Electron microscopy observations were made to examine the clay dispersion in the membrane structure. At variance with Cloisite Na and Cloisite 93A formed microaggregates, Cloisite 30B yielded nanostructures composed of both single sheets and well‐ordered multilayer silicate clusters, which were characterized by an interlayer distance higher than that of the neat clay. The increase in the distance between the layers of Cloisite 30B was related to the formation of intercalated nanocomposites, whereas the presence of single sheets well distributed in the polymer matrix supported the occurrence of delaminated nanocomposites. The intercalation of the polymer into clay layers was confirmed with wide‐angle X‐ray diffractometry. The addition of Cloisite 30B to the casting solution influenced the phase‐separation process in the coagulation bath. Therefore, by the variation of the layered‐silicate concentration in the casting solution, membranes with different morphological structures and ultrafiltration properties were obtained. Cloisite 30B was also found to improve the wettability and mechanical properties of dense films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3637–3644, 2007
Effect of ethylene glycidyl methacrylate compatibilizer on the structure and mechanical properties of clay nanocomposites modified with ethylene vinyl acetate copolymer
Authors: Guduri B. R. , Luyt A. S.
Published: December 2006

The structure and mechanical properties of clay modified with ethylene vinyl acetate copolymer in the presence of ethylene glycidyl methacrylate (EGMA) were investigated as a function of compatibilizer and clay contents. The structure and properties were determined by X‐ray diffraction, transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analysis (TGA). The presence of EGMA caused strong exfoliation of the clay in the polymer matrix, although at higher clay contents, some clay layers still existed. The more effective exfoliation, however, did not seem to substantially influence the tensile properties of the nanocomposites because the EGMA itself had a much stronger influence, which overshadowed any possible influence that the EGMA–clay interaction may have had on these properties. The thermal stability of the nanocomposites (as studied by TGA) improved in the presence of EGMA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4095–4101, 2007
Effect of filler content and size on the properties of ethylene vinyl acetate copolymer–wood fiber composites
Authors: Dikobe D. G. , Luyt A. S.
Published: December 2006

In this study, the main focus was on the effect of wood fiber (WF) content and particle size on the morphology and mechanical, thermal, and water‐absorption properties of uncompatibilized and ethylene glycidyl methacrylate copolymer (EGMA) compatibilized ethylene vinyl acetate copolymer–WF composites. For uncompatibilized composites, the tensile strength decreased with increasing WF content, whereas for compatibilized composites, the tensile strength initially decreased, but it increased for composites containing more than 5% WF. Small‐WF‐particle‐containing composites had higher tensile strengths than composites containing larger WF particles, both in the presence and absence of EGMA. WF particle size did not seem to have much influence on the degradation behavior of the composites, whereas water absorption by the composites seemed to be higher in composites with smaller particle sizes for both compatibilized and uncompatibilized composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3645–3654, 2007
Performance characterization of composite materials based on recycled high‐density polyethylene and ground tire rubber reinforced with short glass fibers for structural applications
Authors: Shojaei A. , Yousefian H. , Saharkhiz S.
Published: December 2006

This study addresses the issue of using recycled materials to obtain low‐cost structural products for practical applications. Through the use and re‐extrusion of virgin high‐density polyethylene (HDPE), the effects of the degradation level of HDPE as a matrix phase on its mechanical properties and the mechanical performance of composites produced with the degraded polyethylene have been examined. The degradation level of HDPE caused by re‐extrusion has been evaluated by the measurement of the melt flow index and mechanical properties of virgin and degraded HDPEs. The results indicate that the modulus and strength of HDPE significantly increase with the addition of polypropylene filled with 30 wt % glass fiber [PP–GF(30)] without any other compatibilizer. However, the final properties of composites with specified glass‐fiber contents are dependent on the degradation level of the matrix phase. In addition, the role of ground tire rubber (GTR) in HDPE/PP–GF(30) systems has been examined by the preparation of composites with various GTR contents without any treatments. The results show that the presence of GTR in the final product results in lower stiffness because of its role as a soft filler, but the elongation of the product increases slightly. Furthermore, GTR does not produce any improvement in the impact properties, probably because of the low interfacial adhesion with the matrix phase; therefore, its content should be kept low in the final composition. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Functional finishing by using atmospheric pressure plasma: Grafting of PET nonwoven fabric
Authors: Shin Younsook , Son Kyunghee , Yoo Dong Il
Published: December 2006

Poly (ethylene terephtalate) (PET) nonwoven fabric was treated with He/O2 plasma to produce peroxides and grafted with acrylic acid (AA) for introducing carboxyl groups onto PET surface. The graft yield increased with AA concentration from 1.5M to 2.5M, and then decreased with further increase in AA concentration. Graft yield increased with sodium pyrosulfite (SPS) concentration from 0.005M to 0.02M, and then decreased with further increase of SPS concentration. X‐ray photoelectron spectroscopy results indicated that both of plasma treatment and AA grafting increased oxygen content and decreased carbon content on the PET nonwoven fabric surface. The grafted PET nonwoven fabric showed increase in moisture regain and dye uptake. And drastic increase in wettability was observed after grafting. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3655–3659, 2007
The effect of zinc oxide addition on the compatibilization efficiency of maleic anhydride grafted high‐density polyethylene compatibilizer for high‐density polyethylene/polyamide 6 blends
Authors: Chatreenuwat Benjamaad , Nithitanakul Manit , Grady Brian P.
Published: December 2006

A high‐density polyethylene with grafted maleic anhydride units has been investigated as a compatibilizer for high‐density polyethylene with polyamide 6. The material acts as an effective compatibilizer, causing a marked reduction in dispersed phase size as well as an increase in tensile strength and toughness. Compatibilizer also affects the glass‐transition temperature, crystallization kinetics, and amount of crystalline material for certain blend compositions. The addition of zinc cations, which are effective in increasing ethylene‐acid copolymer compatibilizer performance in low‐density polyethylene/polyamide blends, has little, if any, effect on compatibilizer performance in these high‐density polyethylene/polyamide blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3871–3881, 2007
Kinetics of thermal degradation of poly(p‐phenylene benzobisoxazole)
Authors: Lin Heng , Zhuang Qixin , Cheng Jianjun , Liu Zitao , Han Zhewen
Published: December 2006

The kinetics of thermal degradation of poly (p‐phenylen benzobisoxazole) (PBO) were studied by thermogravimetric analysis (TG) in dynamic nitrogen gas at four different heating rates: 5, 10, 15, 20°C/min. The activation energy calculated by Kissinger Method was 352.19 kJ/mol, and the mean value of activation energies evaluated by Flynn‐Wall‐Ozawa Method was 338.32 kJ/mol. The degradation kinetic model of PBO followed the mechanism of random scission of weak bonds of PBO molecule and impact of the active groups obtained from the broken bonds, Mampel Power equation with integral form G(α) = α3/2 and differential form
$ f(\alpha)={2\over 3}\alpha^{-1/2} $. And the mathematical equation of kinetic compensation effect was ln A = 0.1365 Ea − 1.4102. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3675–3679, 2007
Influence of an antimicrobial treatment on the strength properties of polyamide/elastane weft‐knitted fabric
Authors: Mihailovic Tatjana , Asanovic Koviljka , Simovic Ljiljana , Skundric Petar
Published: December 2006

Polyamide/elastane weft‐knitted fabric, as a suitable compression material, was treated with gentamicin sulfate and a natural antimicrobial preparation of the autochthonous essential oil of Picea abies. The antimicrobial bioactivity of the treated fabric in vitro was tested for different groups of bacteria and a fungus (Staphylococcus aureus, Escherichia coli, Klabsiella, and Candida albicans). The results of the experiment showed that the antimicrobial‐treated knitted fabric expressed a wide range of bactericidal, fungicidal, and bacteriostatic activity versus the various groups of microorganisms. The influence of the antimicrobial treatments on the tensile strength and elongation, tear strength and elongation, stiffness, and elasticity of the chosen test material was also examined. These properties of the fabric were changed after the antimicrobial treatments. Both the tensile strength and tear strength increased about 14% after the treatment. The scope of the experiment also included the testing of the compression distribution at the skin/knitted fabric interface on the legs of human test subjects. Pressure generated by the application of the knitted fabric on the leg surface increased in correlation with a decrease in the leg circumference. On the basis of these observations, it was concluded that the knitted fabric could be used as a compression textile before and after the treatment. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4012–4019, 2007
Amelioration of acrylonitrile–butadiene copolymer properties using natural rubber graft p‐aminophenol
Authors: El‐Wakil A. A.
Published: December 2006

A two‐roll mill machine was used for the grafting of p‐aminophenol (pAP) onto natural rubber (NR). The prepared NR graft p‐aminphenol (NR‐g‐pAP) was characterized by 1H NMR and IR spectroscopy techniques. The goal of this article is to study the effect of commercial antioxidants, N‐phenyl‐N′‐(1,3‐dimethylbutyl)‐p‐phenylenediamine (6PPD) and N‐phenyl‐N′‐isopropyl‐p‐phenylenediamine (IPPD), and the prepared NR‐g‐pAP, on the mechanical properties of acrylonitrile–butadiene (NBR) vulcanizates, the fluid compatibility of NBR vulcanizates, the hydraulic brake and clutch fluid dot, the diffusion out for NBR vulcanizate components, and the compression recovery of NBR vulcanizates. This study indicates that the NBR copolymer vulcanizate which contains the prepared NR‐g‐pAP has good protection against mechanical stress and the diffusion out of NBR vulcanizate components. The 6PPD and the prepared NR‐g‐pAP ameliorates the fluid compatibility of the oil seals, which is based on NBR as elastomer, and the hydraulic brake and clutch fluid dot. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Reverse atom transfer radical polymerization of MMA via immobilized catalysts in imidazolium ionic liquids
Authors: Li Najun , Lu Jianmei , Xu Qingfeng , Xia Xuewei , Wang Lihua
Published: December 2006

Reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA) employing immobilized catalyst was approached at 50 and 60°C in [C8mim]PF6, and compared with the polymerization of MMA DMF as solvent. Other ionic liquids, [C6mim]BF4, [C8mim]BF4, and [C12mim]BF4, were used as solvents to perform the RATRP of MMA. By comparison, we found that the [C8mim]PF6 was the best solvent in this immobilized catalyst system and the polymerization was best controlled. In addition, the immobilized catalyst spherules can easily separate from the reaction mixture, which avoids the prevalent problem of the catalyst residual in RATRP and also gives us a possibility to recycle the catalyst system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3915–3919, 2007
A serology‐based approach combined with clinical examination of 125 Ro/SSA‐positive patients to define incidence and prevalence of subacute cutaneous lupus erythematosus
Authors: Popovic Karin , Nyberg Fredrik , Wahren‐Herlenius Marie , Nyberg Filippa
Published: December 2006

Objective

To estimate the incidence and prevalence of Ro/SSA‐positive subacute cutaneous lupus erythematosus (SCLE) in Stockholm County, Sweden (1.8 million inhabitants) and to investigate the frequency of photosensitivity and other clinical manifestations associated with Ro/SSA autoantibodies.

Methods

Ro/SSA‐positive patients in Stockholm were identified via registry‐based searches. All patients who tested positive for the presence of Ro/SSA autoantibodies during 1996–2002 (n = 1,323; 85% women) were identified. A questionnaire was sent to all patients still living in Stockholm in 2003 (n = 1,048). Patients who reported having skin symptoms and photosensitivity (n = 125) underwent a clinical examination.

Results

Of the 741 (71%) of 1,048 Ro/SSA‐positive patients who responded to the questionnaire, 400 (54%) reported having photosensitivity, and of these patients, 125 agreed to be clinically examined. A diagnosis of LE was confirmed in 59 of the 125 patients (SCLE in 20, systemic LE [SLE] in 33, and chronic CLE in 6). Eighty‐six patients reported experiencing symptoms consistent with polymorphous light eruption (PLE). Comorbidities such as cardiovascular disease, autoimmune disease, and other skin diseases were common. The incidence of Ro/SSA‐positive SCLE during the study period was estimated to be 0.7 cases per 100,000 persons per year and the prevalence was ∼6.2–14 in 100,000 persons.

Conclusion

The incidence of Ro/SSA‐positive SCLE in Stockholm County, Sweden is estimated to be 0.7 per 100,000 persons per year as compared with an incidence of SLE in Sweden of 4.8 per 100,000 persons per year. The prevalence is estimated to be 6.2–14 in 100,000 persons. Self‐reported photosensitivity commonly corresponds to a history of PLE in Ro/SSA‐positive patients, even when the clinical profile of SCLE is absent. Photoprotection should therefore be included in the treatment recommendations for these patients.