bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and characterization of bioadhesive grafted starch copolymers as platforms for controlled drug delivery
Authors: Geresh Shimona , Gilboa Ygal , Peisahov‐Korol Julia , Gdalevsky Garik , Voorspoels Jody , Remon J. P. , Kost Joseph
Published: August 2002

60Co‐gamma‐radiation and ceric ammonium nitrate (CAN) redox‐induced graft polymerization of acrylic monomers (acrylonitrile, acrylic acid, and methyl acrylate) to starch was performed to produce drug‐delivery systems. The grafted starches obtained mainly by redox‐induced polymerization were characterized by chemical and physicochemical methods, and the nature and size of the polyacrylic moiety grafted to the starch were determined. Although the choice of grafting method depended in part on the particular monomer, only copolymers obtained by gamma radiation proved to be satisfactory drug delivery systems. Changes of parameters in the gamma radiation–induced polymerization, such as radiation times and changes in the amount of starch and/or acrylic monomers, were tested in terms of the release rate of model drug compounds. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1157–1162, 2002
Inverted emulsion cast electrically conducting polyaniline–polystyrene blends
Authors: Rao Palle Swapna , Sathyanarayana D. N.
Published: August 2002

An inverted emulsion method for the synthesis of electrically conductive polyaniline–polystyrene blends of different compositions (10, 30, 50, 70, and 85%, wt/wt) is described. Polymerization of aniline is carried out in chloroform in the dispersed phase by using benzoyl peroxide as a novel oxidant and sulfosalicylic acid as the dopant. The blends synthesized with benzoyl peroxide as the oxidant are of high purity and the excess benzoyl peroxide is readily removed with acetone, which is used to break the emulsion and precipitate the polymer. The absorption spectra, FTIR, FT Raman, and electron paramagnetic resonance spectroscopy confirm the presence of polyaniline in the salt form and polystyrene in the blend. The thermal stability of polyaniline salt decreases with an increase in polystyrene content in the blend. The SEM studies show that the particles of polyaniline–sulfosalicylic acid are dispersed on the polystyrene surface. The blends of polyaniline–polystyrene prepared by the present method were found to display conductivities as high as 0.5–0.1 S cm−1. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1163–1171, 2002
A water‐developable negative photoresist based on the photocrosslinking of N‐phenylamide groups with reduced environmental impact
Authors: Chae Kyu Ho , Sun Gum Ju , Kang Jin Koo , Kim Taek Hyeon
Published: August 2002

A water‐developable negative photoresist based on the photocrosslinking of N‐phenylamide groups was prepared by the copolymerization of 4‐styrenesulfonic acid sodium salts (SSS) with N‐phenylmethacrylamide (copolymer A) or p‐hydroxy‐N‐phenylmethacrylamide (copolymer B), and its properties such as solubility changes, photochemical reaction, and photoresist characteristics were studied. The copolymer containing a relatively higher amount of SSS units was soluble in water. Solubility changes of the copolymers in the various buffer solutions of pH 4 ∼ 11 and in water upon irradiation were observed by the measurement of insoluble fraction. The copolymers were soluble in water before irradiation, whereas they became insoluble upon irradiation with the UV light of 254 nm. The photochemical reaction of the copolymer studied by the UV and IR absorption spectroscopies indicated that a photo‐Fries rearrangement was favored for copolymer A, whereas a photocrosslinking reaction was predominate for copolymer B. Resist properties of the copolymers were studied by measurement of the normalized thickness and by development of the micropattern. Negative tone images with a resolution of 1 μm were obtained with these materials that have a sensitivity (D) of ∼ 1100 mJ/cm2 with an aqueous developing process.© 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1172–1180, 2002
Production of antimicrobially active silk proteins by use of metal‐containing dyestuffs
Authors: Tsukada Masuhiro , Katoh Hiroshi , Wilson Donna , Shin Bong‐Seob , Arai Takayuki , Murakami Ritsuko , Freddi Giuliano
Published: August 2002

The work presented here discusses a new technique for preparing silk fibers and films with persistent antimicrobial activity through use of metallic dyestuffs during the fiber dyeing process. The length of the silk fibers investigated contracted when the fibers were immersed in concentrated neutral salt solutions, such as calcium or potassium nitrate, at elevated temperature levels. The birefringence and molecular orientation of the silk fibroin molecules became less ordered by the action of the neutral salt solutions, resulting in increased dyestuff absorption. Subsequently, contracted silk fibers were dyed with metallic dyestuffs containing Cr or Cu for the purpose of obtaining silk fibers with antimicrobial activity. Silk fibers dyed with metallic dyestuffs showed significant antimicrobial activity against the plant pathogen Cornebacterium and the human pathogen Coli bacillus. Tensile strength of the silk fibers after the salt shrinking and dyeing processes did not show a significant change, whereas the elongation at break was increased slightly. The techniques described here for preparing significantly active antimicrobial silk fibers are effective and economic ways of providing new materials for industrial and biomedical applications. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1181–1188, 2002
Gelatin/montmorillonite hybrid nanocomposite. I. Preparation and properties
Authors: Zheng Jun Ping , Li Ping , Ma Ya Lu , Yao Kang De
Published: August 2002

Gelatin/montmorillonite (MMT) hybrid nanocomposite was directly prepared with unmodified MMT and gelatin aqueous solution. Thermal and mechanical properties of the composite were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and tensile tests. The results indicated that an intercalated or partially exfoliated nanocomposite could be achieved, and the properties of the composite were significantly improved. A Tg peak of high temperature disappeared in the DSC curve of the composite, and the thermogravity and thermally decomposed rate decreased obviously. The tensile strength and Young's modulus were also improved notably, which varied with MMT content, as well as the pH of gelatin matrix. Meanwhile, SEM photographs showed a plasticizing trend of gelatin fracture surface due to intercalation with MMT. Furthermore, the wet mechanical behavior was initially studied. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1189–1194, 2002
Preparation of microporous chlorinated poly(vinyl chloride) membrane in fabric and the characterization of their pore sizes and pore‐size distributions
Authors: Kang Jong Seok , Kim Ki Yoen , Lee Young Moo
Published: August 2002

Chlorinated poly(vinyl chloride) (CPVC)/poly(vinyl pyrrolidone) (PVP) membranes were prepared by using the solvent system tetrahydrofuran (THF)/n‐butyl alcohol (n‐BA) to investigate the possibility of pore size and pore‐size distribution control. The coagulation of CPVC/PVP solution was induced by the exposure to water vapor at 25 (±0.5)°C. The average pore diameter, dp, and the size distribution of pores on the surface of the membrane were quantified through the image analyzer from the images visualized by field emission scanning electron microscope (FE‐SEM). Surface pore size and distribution of the prepared CPVC/PVP membrane were strongly affected by the relative humidity (RH) in the environment and the content of PVP used as an additive. Particularly, in the case of CPVC membrane without PVP, the mean pore size was 0.15–0.2 μm, depending on the RH. The pore distribution became broad with the increase of the RH. The membranes had open pores as confirmed by the hydraulic permeation experiment. In addition, the water flux and membrane resistance (Rm) were greatly affected by the composition of polymer solution and the RH. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1195–1202, 2002
Enhancement of the high‐temperature properties of an SEBS thermoplastic elastomer by chemical modification
Authors: Wright Timothy , Jones Allan S. , James Harwood H.
Published: August 2002

A procedure was developed for benzoylating the polystyrene segments in polystyrene‐b‐poly(ethylene‐co‐butene)‐b‐polystyrene (SEBS) triblock copolymers. The products were characterized by NMR spectroscopy, gel permeation chromatography, dynamic mechanical thermal analysis, and membrane osmometry. The mechanical properties of the parent and benzoylated copolymers, measured from 25 to 150°C, indicated that benzoylation increases the utility of the polymers at elevated temperatures. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1203–1210, 2002
Melting behavior and surface morphology of poly(vinyl acetate‐co‐vinyl alcohol) copolymer
Authors: Thombre Sunita
Published: August 2002

In a study of the surface morphology of commercial poly(vinyl acetate‐co‐vinyl alcohol) (ACA copolymer) with different percents of hydrolysis, different structures like fibrils, spherulites, micelles, vesicles, and spheroids were seen. The copolymer was crystallized by annealing at two different temperatures. The morphology of the polymer after crystallization and also without crystallization was studied. A decrease in the melting temperature just by heating to the melting temperature was observed, and for a detailed study, repetitive heating of the copolymer was carried out and changes in the mass and heat of fusion after every heating was recorded. The morphology of the copolymer after repetitive heating was studied. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1211–1218, 2002
UV polarizers based on oriented poly(vinyl alcohol)–Chrysophenine–Congo red blend films
Authors: Beekman Elissa , Kocher Christoph , Kokil Akshay , Zimmermann Sven , Weder Christoph
Published: August 2002

The availability of efficient low‐cost ultraviolet (UV) film polarizers is of vital importance to a number of applications, which rely on the use of polarized light in the near‐UV regime. We describe here the preparation of such elements based on stretch‐oriented films comprising poly(vinyl alcohol) and a combination of two commercially available azo dyes, Congo Red and Chrysophenine. Films of various dye contents were prepared and oriented by uniaxial tensile deformation. Moderately stretched films (draw ratio l/l0 = 4–8) exhibit a pronounced optical dichroism, characterized by a polarizing efficiency up to 0.98 at a wavelength of 365 nm. Initial experiments suggest that, even under rather harsh irradiation conditions and without any packaging, these azo‐dye‐based polarizers are surprisingly inert under simulated operating conditions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1235–1239, 2002
Preparation of poly(vinyl alcohol) films with promising physical properties in comparison with commercial polyethylene film
Authors: Abd El‐Kader K. A. M. , Abdel Hamied S. F.
Published: August 2002

Poly(vinyl alcohol) (PVA) films with different thicknesses (0.08, 0.2, 0.23, 0.42 mm) were prepared by a casting technique. The transmission and the absorption of the PVA films were measured as functions of the wavelengths. PVA film with a thickness of 0.42 mm showed zero transmission in the wavelength range of 190–350 nm. The transmission spectrum of a commercial polyethylene film with a thickness of 0.21 mm was compared to the transmission spectrum of PVA film with a thickness of 0.42 mm. A correlation was found between the two transmission spectra in the region 190–350 nm and a 20% increase in the transmission of the PVA film in comparison with the transmission of commercial polyethylene in the region 350–1500 nm. The near‐infrared region of the transmission of commercial polyethylene was increased by 15% with respect to the transmission of the PVA film. The stress–strain measurements were done for PVA and commercial polyethylene films. The Young's modulus and the strength at break for PVA films are higher by two orders of magnitude than those for commercial polyethylene film. The strain at break for commercial polyethylene is 17% lower than that for PVA film. Radiation effects on the optical properties of PVA and commercial polyethylene films were investigated. The PVA and commercial polyethylene films were irradiated with a xeon arc lamp at 3.5–5 W/cm2. The optical properties for PVA and commercial polyethylene films were studied after irradiation. The obtained results showed that PVA film with a thickness of 0.42 mm gave promising properties which could be used in technological applications. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1219–1226, 2002
Evaluations of an aramid fiber in nonwoven processes for honeycomb applications
Authors: Wu Yi‐Jui , Seferis James C. , Lorentz Vincent
Published: August 2002

Aromatic polyamide paper has been used as the primary honeycomb core material in aircraft interior applications because of its flame‐resistant properties. This study investigated the relationships between material requirements in making sheets for honeycomb core applications by characterizing and processing a model aramid fiber into nonwoven samples, which were further characterized and whose adaptability in honeycomb application was evaluated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1149–1156, 2002
Ionomeric polyurethanes of pyridinium type with side azobenzene groups
Authors: Buruiana Tinca , Buruiana Emil C.
Published: August 2002

New polyurethane cationomers synthesized by a two‐step substitution postreaction of urethane hydrogen atoms with nitroazobenzene groups were studied. As a starting polymer, a polyurethane based on poly(tetramethylene oxide)diol, isophorone diisocyanate, and 2,6‐bis(hydroximethyl)pyridine was used. After a preliminary metalation of the above polymer with natrium hydride, by reaction of polyurethane N‐sodate with 4‐nitro‐4′(β–iodoethylurethane)azobenzene, chromophoric groups between 2.85 and 10.53 wt % could be incorporated instead of hydrogen. Such polymers partially functionalized with azobenzene and further quaternized with methyl iodide led to the formation of pyridinium polyurethane cationomers N‐modified with nitroazo groups. The photosensible properties of the azobenzene chromophore in a polymer solution and film state indicated important differences in their photoresponse. In the polymer solution, the trans–cis photoisomerization of the chromophore is accompanied by an irreversible photobleaching effect, while under the same UV irradiation conditions, the ionomeric films exhibited an enhanced photostability. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1240–1247, 2002
The effects of plasticizers on the dynamic mechanical and thermal properties of poly(lactic acid)
Authors: Ljungberg Nadia , Wesslén Bengt
Published: August 2002

Poly(lactic acid) (PLA) was blended with five plasticizers in a batchwise mixer and pressed into films. The films were analyzed by means of dynamic mechanical analysis and differential scanning calorimetry to investigate the properties of the blends. Triacetine and tributyl citrate proved to be effective as plasticizers when blended with PLA. The glass transition temperature of PLA decreased linearly as the plasticizer content was increased. Both plasticizers were miscible with PLA to an extent of ∼ 25 wt %. At this point, the PLA seemed to be saturated with plasticizer and the blends tended to phase separate when more plasticizer was added. There were also signs of phase separation occurring in samples heated at 35, 50, and 80°C, most likely because of the material undergoing crystallization. The presence of the plasticizers induced an increased crystallinity by enhancing the molecular mobility. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1227–1234, 2002
Surface morphology of adsorbed sulfur‐functionalized polystyrene thin film on gold on the basis of atomic force microscopic observation
Authors: El Sayed A. Mounir
Published: August 2002

Polystyrene thin film containing one‐terminal thiol (PS–SH) was spin‐coated and adsorbed from 0.1 to 0.001 wt % of polymer solution in toluene onto evaporated gold (Au) film supported on Si‐wafer substrate. The effect of polymer solution concentration on the aggregation structure of PS–SH thin films was determined on the basis of atomic force microscopic (AFM) observation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1248–1252, 2002
Miscibility and morphology of chiral semicrystalline poly‐(R)‐(3‐hydroxybutyrate)/chitosan and poly‐(R)‐(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/chitosan blends studied with DSC, 1H T1 and T1ρ CRAMPS
Authors: Cheung Man Ken , Wan Kris P.Y. , Yu Peter H.
Published: August 2002

The phase structure of poly‐(R)‐(3‐hydroxybutyrate) (PHB)/chitosan and poly‐(R)‐(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (P(HB‐co‐HV))/chitosan blends were studied with 1H CRAMPS (combined rotation and multiple pulse spectroscopy). 1H T1 was measured with a modified BR24 sequence that yielded an intensity decay to zero mode rather than the traditional inversion‐recovery mode. 1H T1ρ was measured with a 40‐kHz spin‐lock pulse inserted between the initial 90° pulse and the BR24 pulse train. The chemical shift scale is referenced to the methyl group of PHB as 1.27 ppm relative to tetramethylsilane (TMS) based on 1H liquid NMR of PHB. Single exponential T1 decay is observed for the β‐hydrogen of PHB or P(HB‐co‐HV) at 5.4 ppm and for the chitosan at 3.7 ppm. T1 values of the blends are either faster than or intermediate to those of the plain polymers. The T1ρ decay of β‐hydrogen is bi‐exponential. The slow T1ρ decay component is interpreted as the crystalline phase of PHB or P(HB‐co‐HV). The degree of crystallinity decreases with increasing wt % of chitosan in the blend. The fast T1ρ of β‐hydrogen and the T1ρ of chitosan in the blends either follow the same trend as or faster than the weight‐averaged values based on the T1ρ of the plain polymers. Together with the observation by differential scanning calorimeter (DSC) of a melting point depression and one effective glass transition temperature in the blends, the experimental evidence strongly suggests that chitosan is miscible with either PHB or P(HB‐co‐HV) at all compositions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1253–1258, 2002
New conductive thermoplastic elastomers. Part II. Physical and chemical‐physical characterization
Authors: Carone E. , D'Ilario L. , Martinelli A.
Published: August 2002

To overcome the problems relevant to the low processbility and scarce mechanical properties of polyaniline, in a previous work we have proposed the synthesis of elastomeric conducting copolymers prepared by grafting polyaniline (EB) or sulfonated polyaniline (SPAN) chains to the backbone of a carboxylated segmented polyurethane (PEUA). In the present work the physical and chemical‐physical properties of the copolymers are investigated. As evidenced by thermal (DSC) and dynamo‐mechanical (DMTA) characterization, the introduction of EB or SPAN in the matrix enhances the hard‐soft phase segregation effect, because of the strong tendency of the conductive polymer chains to aggregate. Moreover, the EB and SPAN chains, grafted to the polyurethane backbone, acting as reinforcing filler, give rise, compared with the mechanical properties of the insulating matrix, to an increase of the Young modulus and a decrease of the tensile set. When the copolymers are HCl doped their electrical conductivity increases many orders of magnitude, reaching values of about 10−3 Ω−1 cm−1. The conductivity, measured along the deformation direction, may be further increased by stretching the copolymer films. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1259–1264, 2002
Acetyl‐capped paraformaldehyde as crosslinking agent for BMI‐modified novolac resin for resin transfer molding
Authors: Yan Yehai , Zhi Linjie , Wang Hongsheng , Liu Jinge , Zhao Tong , Yu Yunzhao
Published: August 2002

Paraformaldehyde was end‐capped with acetyl groups and was applied as a crosslinking agent for a bismaleimide (BMI)‐modified novolac resin system. The processibility of the resin system containing 5 wt % crosslinking agent still met the need for resin transfer molding (RTM), whereas the thermomechanical properties of crosslinked resin improved significantly. The composites based on the resin system and woven glass fabric showed better flexural strength, modulus, and higher retention rates at 200 and 300°C than that based on a resin system without acetyl‐capped paraformaldehyde. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1265–1271, 2002
Radiation effects on LDPE/EVA blends
Authors: Dalai Siqin , Wenxiu Chen
Published: August 2002

Radiation effects of low‐density polyethylene/ethylene‐vinyl acetate copolymer (LDPE/EVA) blends were discussed. EVA content in the LDPE/EVA blends was an enhancement effect on radiation crosslinking of LDPE/EVA blends, and the highest radiation crosslinking was obtained when the EVA content was reached at 30% when irradiated by γ‐ray in air. The phenomenon was discussed with the compatibility, morphology, and thermal properties of LDPE/EVA blends and found that the enhanced radiation crosslinking of the LDPE/EVA blends was proportional to the good compatibility, the increasing degree of the amorphous region's content of the LDPE/EVA blends, and the vinyl acetate content of EVA. We also found that the vinyl acetate of EVA in the blends is easily oxidized by γ‐ray irradiation in air. The possible radiation crosslinking and degradation mechanism of LDPE/EVA blends was discussed quantitatively with a novel method “step‐analysis” process of irradiated LDPE/EVA blends in the thermal gravimetric analysis (TGA) technique. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1296–1302, 2002
Relations between molecular mixing state and conductive property in blends composed of polyaniline and aliphatic copolymer having acid groups
Authors: Yamada Kenji , Yamane Hirokazu , Haishi Teruki , Yamamoto Katsuhiro , Haraguchi Toshihide , Kajiyama Tisato
Published: August 2002

Blend films composed of polyaniline and aliphatic copolymer having carboxylic acid groups were prepared by vaporizing a solvent from a solution of both polymers. Poly(methyl methacrylate‐co‐methacrylic acid) and poly(1‐vinylpyrrolidone‐co‐acrylic acid) were used as the copolymers in this work. Conductivity of the blend film increased with decreasing concentration of polyaniline and then decreased in the region of low concentration. The N1s peak in the ESCA spectrum of the blend film was shifted to higher binding energy with decreasing concentration of polyaniline and then was done to lower the binding energy in the region of low concentration. Polyaniline chains in the blend films become conductive by being oxidized with the carboxylic acid groups, which are the constituents of the copolymers. Through strong intermolecular interactions such as ionic bonding and hydrogen bonding between polyaniline and the copolymer, densities of the blend films are always higher than those predicted on the basis of the additive law. Blend films with higher density and higher conductivity are able to be prepared with a higher vaporizing rate, given that phase separation occurring during vaporizing process can be depressed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1113–1117, 2002
Surface structure of radiation‐grafted polyethylene‐g‐polyacrylamide films
Authors: Gupta Bhuvanesh , Anjum Nishat
Published: August 2002

Modification of polyethylene films was carried out by radiation‐induced graft polymerization of acrylamide using a preirradiation method. The surface behavior of grafted films as a function of the degree of grafting was determined using contact angle measurements, attenuated total reflectance (ATR), and scanning electron microscopy (SEM). In spite of the presence of hydrophilic polyacrylamide chains, grafted films still showed high hydrophobicity on the surface. ATR results revealed the presence of a polyacrylamide moiety in the surface layer of the films. Interestingly, the contact angle of grafted films did not change much for the entire range of degree of grafting. SEM results showed that the roughness is introduced on the film surface irrespective of the nature of the additive. However, the addition of acetone to the grafting medium was the most effective in increasing the surface roughness. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1118–1122, 2002
Relations between the molecular aggregation state and ionic conductivity in photopolymerized crosslinking polymers with oligo(oxyethylene) chains
Authors: Yamada Kenji , Iwamoto Naoya , Yamane Hirokazu , Haraguchi Toshihide , Kajiyama Tisato
Published: August 2002

A mixture of a vinyl monomer and a crosslinking agent was photopolymerized to form a crosslinked polymer film. Methacrylate with pendant oligo(oxyethylene) chain and poly(ethylene glycol) dimethacrylate were used as the vinyl monomer and crosslinking agent, respectively. The ionic conductivity of the film increased with an increasing concentration of LiClO4 and then decreased. The size of the quasicrystalline aggregation phase composed of pendant and crosslinking chains in the film decreased with an increasing concentration of LiClO4. The amorphous pendant and crosslinking oxyethylene chains gave rise to increased segmental motion and conductivity. The dissolution was depressed for a decrease in the ionic conductivity at a high LiClO4 concentration at which the interactions among ions became stronger and the crystal phase of LiClO4 was formed. The amount of the dissolution of the aggregation phase increased with an increasing crosslinking agent concentration. The quasicrystalline aggregation phase became larger with an increasing length of the pendant chains, and an increase in the size of the aggregation phase resulted in a decrease in the ionic conductivity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1272–1277, 2002
Synthesis, characterization, and thermal properties of phosphorus‐containing, wholly aromatic thermotropic copolyesters
Authors: Wang Yu‐Zhang , Chen Xiao‐Ting , Tang Xu‐Dong
Published: August 2002

A series of phosphorus‐containing, wholly aromatic thermotropic copolyesters from acetylated 2‐(6‐oxide‐6H‐dibenz〈c,e〉〈1,2〉oxa phosphorin‐6‐yl)‐1,4‐dihydroxy phenylene, p‐acetoxybenzoic acid, terephthalic acid, and isophthalic acid were prepared by melting polycondensation. The structure and basic properties of the polymers, such as the glass‐transition temperature (Tg), melting temperature (Tm), thermal stability, crystallinity, and liquid crystallinity, were investigated with Fourier transform infrared, elemental analysis, differential scanning calorimetry (DSC), thermogravimetric analysis, wide‐angle X‐ray diffraction, and hot‐stage polarizing optical microscopy. The copolyesters had relatively high Tg values ranging from 183 to 192°C. The Tm values obtained from DSC curves for samples P‐20 and P‐25 were 290 and 287°C, respectively (where the number in the sample name indicates the molar fraction of the phosphorus‐containing monomer in the reactants). The initial flow temperatures of other samples observed with hot‐stage polarizing microscopy were 271–290°C. The 5% degradation temperatures in nitrogen ranged from 431 to 462°C, and the char yields at 640°C were 41–52%. All the copolyesters, except P‐40, were thermotropic and nematic. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1278–1284, 2002
Development of polylactide microspheres for protein encapsulation and delivery
Authors: Chandy Thomas , Das Gladwin S. , Wilson Robert F. , Rao Gundu H. R.
Published: August 2002

The development of injectable microparticles for protein delivery is a major challenge. We demonstrated the possibility of entrapping human serum albumin (HSA) and thrombin (Thr) in poly(ethylene glycol) (PEG)‐coated, monodisperse, biodegradable microspheres with a mean diameter of about 10 μm. In our earlier studies, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis was used to characterize the surface of PEG‐coated, taxol‐loaded poly(lactic acid) (PLA) microspheres. An analysis by DRIFTS revealed that PEG was incorporated well on the PLA microsphere surface. An emulsion of protein (in water) and PLA dissolved in an acetone–dichloromethane (or acetone–chloroform) mixture were poured into an aqueous solution of PEG [or poly(vinyl alcohol) (PVA)] with stirring with a high‐speed homogenizer for the formation of microparticles. HSA recovery in microspheres ranged from 13 to 40%, depending on the solvent and emulsification systems used for the preparation. PLA dissolved in a dichloromethane/acetone system and albumin loaded via a PEG emulsification solution (PLA–PEG–HSA) showed maximum drug recovery (39.5%) and drug content (9.9%). Scanning electron microscopy revealed that PEG‐coated microspheres had less surface micropores than PVA‐based preparations. The drug‐release behavior of microspheres suspended in phosphate‐buffered saline exhibited a biphasic pattern. An initial burst release (30%) followed by a constant slow release for 20 days was observed for HSA and Thr from PLA–PEG microspheres. PEG‐coated PLA microspheres show great potential for protein‐based drug delivery. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1285–1295, 2002
Impact resistance of fibrous glass reinforced plastics using polycarbonate‐polydimethylsiloxane block copolymer
Authors: Okamoto Masaya
Published: August 2002

By using reactive polydimethylsiloxanes that have phenolic hydroxyl groups at the ends of the chain, a polycarbonate‐polydimethylsiloxane (PC‐PDMS) block copolymer was prepared, and the properties of fibrous glass reinforced plastics (GF‐PC) using this copolymer were examined. The Izod impact value of the PC‐PDMS/GF composite increases with an increase in the degree of polymerization of reactive PDMS (n) between 40 and 160. When n is 40, the Izod impact value of the PC‐PDMS/GF composite is equal to that of the PC/GF composite. The Izod impact value is independent of the PDMS content of the copolymer when it is between 2 and 4 wt %. The PC‐PDMS/GF composite is superior, in the balance between fluidity and impact resistance, to the PC/GF composite. From the results of SEM, adhesion between the polymer and GF of the PC‐PDMS/GF composite is superior to that of the PC/GF composite. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1123–1127, 2002
Study of the I–V characteristics of organic light‐emitting diodes based on thiophene vynilic derivatives
Authors: Brovelli F. , Bernède J. C. , Marsillac S. , Díaz F. R. , Del Valle M. A. , Beaudouin C.
Published: August 2002

Organic light‐emitting diodes were obtained using a thiophene vynilic derivative polymer electrochemically synthesized. The electrochemistry of the thiophene vynilic derivative, 1,5‐bis(2‐thienyl)‐1,4‐pentadien‐3 one (CDV), was conducted in a nonaqueous media. The polymer was deposited on tin oxide (SnO2)‐coated glass substrates. The films obtained were physicochemically characterized by infrared absorption, a scanning microscope, microprobe X‐ray photoelectron analysis, and photoluminescence measurements. It was shown that the coverage efficiency of the films is very high. There is some oxygen contamination, not only at the surface, but also in the bulk of the polymers. The films are photoluminescent with emission between 660 and 720 nm. The current–voltage (I–V) characteristics exhibit a turn‐on voltage at about 2–4 V depending on the film thickness (120–250 nm). The electroluminescence–voltage (EL–V) curve has a similar shape but a shift of 1–2 V toward higher voltage. In the conducting state, there is no significant dependence of the temperature upon the current. All these facts cannot be explained easily by a simple thermionic model; a thermally activated tunneling effect appears more adequate. The current in the small potential domains has a behavior more or less erratic with a differential negative resistance and a switching effect. This behavior, arising from localized pathways, has a nature different from the injection processes, allowing electroluminescence. These pathways are related to surface heterogeneities (SnO2/polymer films) and aluminum diffusion. By not being directly related to electroluminescence, these pathways could induce a heating effect and an irreversible short‐circuit effect. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1128–1137, 2002
Remote detection and identification of organic remains: an assessment of archaeological potential
Authors: Ruffell Alastair
Published: August 2002

This paper reviews the various methods of using natural or induced light spectra as analytical tools in forensic archaeology. Chemical identification can be made at long range and wide scale (tens of metres) down to short range and very small scale (nanometres). The identification of organic gases and materials has used either chemical capture and chromatography, induced (laser or ultraviolet) light sources or laser Raman microscope spectroscopy. The remote gas detection method relies on the identification of atmospheric gases by their characteristic light spectra. Modern spectroscopes can detect gases down to a few parts per million of an atmosphere. When the light source (wavelength) and direction is controlled, so laser‐induced spectroscopy may be used to monitor the emission of gases such methane from buried organic remains. In order to identify the location of buried organic remains, a grid of sample points must be established using a base line or global positioning system. When matched to base line or ground‐positioning systems, such data can be manipulated by geographical information system packages. This would enable pinpointing of anomalies for excavation or avoidance. Microscope‐based laser Raman spectroscopy can be used to directly analyse captured gases, swabs and surfaces without the problems of long‐path detection. Copyright © 2002 John Wiley & Sons, Ltd.
The geophysical evaluation of British lead and copper working sites. Comparisons with iron working
Authors: Vernon R. W. , McDonnell G. , Schmidt A.
Published: August 2002

Recent research at the University of Bradford has been very effective in evaluating early iron‐working sites using geophysical techniques. In addition, lead and copper smelting sites have been surveyed with a fluxgate gradiometer. Although the fluxgate gradiometer readings from these sites are lower than those from iron‐smelting sites it is possible to identify anomalies related to the different smelting methods. The paper provides details of some of the surveys and the different features that may be identified. Magnetic susceptibility measurements of selected slag samples provided additional information. Copyright © 2002 John Wiley & Sons, Ltd.
Georadar in the Roman civil town Carnuntum, Austria: an approach for archaeological interpretation of GPR data
Authors: Neubauer W. , Eder‐Hinterleitner A. , Seren S. , Melichar P.
Published: August 2002

The case study presented is a prime example of integrated geophysical–archaeological prospection. The aerial photographs available are complemented by non‐destructive geomagnetic and geoelectric surveys with a reading distance of 0.5 m or less. To gain depth information and provide higher resolution, ground‐penetrating radar (GPR) data are integrated. The GPR data were collected in a 0.5 × 0.05 m raster and visualized as black‐and‐white time or depth slices. The developments presented allow us to incorporate GPR into the standardized interpretation process of archaeological prospection based on a geographical information system (Grs). Using GPR and all the other prospection data available as a basis, a detailed three‐dimensional interpretation model of the monument detected, the southern part of the forum of the civil town of Roman Carnuntum, is created. Copyright © 2002 John Wiley & Sons, Ltd.
Magnetic mapping and dating of prehistoric and medieval iron‐working sites in northwest Wales
Authors: Crew Peter
Published: August 2002

As part of a long‐term research project on prehistoric and medieval iron‐working sites in northwest Wales, a technique has been developed for processing magnetic survey data to improve the presentation and recognition of the high‐amplitude dipolar signals that are characteristic of iron‐smelting furnaces. This technique has now been used successfully on some 37 British iron‐working sites. High‐resolution surveys, on a 10‐cm grid, have been made both by caesium magnetometer and fluxgate gradiometer over four prehistoric furnaces and one medieval furnace giving detailed maps of their magnetic signals. Mathematical models of these maps, using multiple dipoles, has given estimates of the directions of total magnetization of the furnaces. Three of the furnaces were also surveyed at subsequent stages of excavation and after the removal of the furnace, giving the background signal. The background signals can then be subtracted from the survey data to give clean residual maps. These are easier to model, giving more reliable results, and they give useful information on the contribution of the different furnace materials to the overall magnetic signals. The corrections required for the influence of induced magnetism and for viscous remanent magnetism are examined. The results are compared with the British archaeomagnetic curve, and with the archaeomagnetic date estimates from three of the furnaces, to assess the value of the modelling technique in giving usable estimates of the date of last firing of the furnaces. Copyright © 2002 John Wiley & Sons, Ltd.
Capillary electrophoresis of Cr(VI) reducer Arthrobacter oxydans
Authors: Tsibakhashvili Nelly Ya. , Asatiani Nino V. , Abuladze Marina K. , Birkaya Barbara G. , Sapojnikova Nelly A. , Mosulishvili Liguri M. , Holman Hoi‐Ying N.
Published: August 2002

Rapid and effective separation of bacteria Arthrobacter oxydans was performed using capillary electrophoresis. For optimal separation of bacteria the influence of buffer concentration, pH and applied voltage were studied. It was found that the most appropriate conditions for electrophoretic mobility measurements are as follows: applied voltage 6–14 kV; buffer concentration 5–10 mM pH 6–8. At the stationary phase of growth there are always two main heterogeneous peaks. They are connected with the morphology of bacteria as well as with cell aggregation. The heterogeneity of samples may be explained by surface modifications of bacterial cells. Copyright © 2002 John Wiley & Sons, Ltd.
On‐Line HPLC‐UV‐mass spectrometry and tandem mass spectrometry for the rapid delineation and characterization of differences in complex mixtures: a case study using toxic oil variants
Authors: Crow Frank W. , Cragun Jennifer D. , Johnson Kenneth L. , Ruiz Maria Victoria , Posada de la Paz Manuel , Naylor Stephen
Published: August 2002

An integrated differential approach to the characterization of complex mixtures is presented which includes the targeting of liquid chromatography (LC) peaks for identification using characteristic UV adsorption of the LC peak, subsequent molecular weight and formula determination using accurate mass LC mass spectrometry (MS), and structure characterization using accurate mass LC‐tandem mass spectrometry. The use of differential UV adsorption aids in narrowing the scope of the study to only specific peaks of interest. Accurate mass measurement of the molecular ion species provides molecular weight information as well as atomic composition information. The tandem MS (MS/MS) spectra provide fragmentation information which allows for structural characterization of each component. Accurate mass assignment of each of the fragment ions in the MS/MS spectrum provides atomic composition for each of the fragment ions and thus further aids in the structural characterization. These experiments are facilitated through the use of on‐line LC‐MS and LC‐MS/MS with in‐line UV detection. A synthetic toxic oil (STO) related to Toxic Oil Syndrome is studied with a focus on possible contaminants resulting from the interaction of aniline, used as a denaturant, with the normal components of the oil. A differential analysis between the STO and a control oil is performed. LC peaks were targeted using UV absorbance to indicate the possible presence of the aniline moiety. Further differential analysis was performed through the determination of the MS signals associated with each component separated on the LC. Finally, the MS/MS data was also used to determine if the fragmentation of the targeted components indicated the presence of aniline. The MS/MS and accurate mass data were used to assign the structures for the targeted components. Copyright © 2002 John Wiley & Sons, Ltd.
Liquid chromatographic resolution of gemifloxacin mesylate on a chiral stationary phase derived from crown ether
Authors: Hyun Myung Ho , Han Sang Cheol , Cho Yoon Jae , Jin Jong Sung , Lee Wonjae
Published: August 2002

A new racemic fluoroquinolone antibacterial agent, gemifloxacin mesylate, has been successfully resolved on a chiral stationary phase (CSP) derived from (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid. Compared to the Crownpak CR(+) column, the CSP used in this study was more effective for the resolution of racemic gemifloxacin mesylate, especially in terms of analytical time. The resolution of gemifloxacin mesylate enantiomers on the CSP was found to be dependent on the type and content of organic and acidic modifiers in the aqueous mobile phase and the column temperature. Copyright © 2002 John Wiley & Sons, Ltd.
Mass spectrometric detection in chromatography. Trends and perspectives
Authors: Cserháti Tibor
Published: August 2002

The newest results in the use of miscellaneous mass spectrometric detection methods in various chromatographic techniques are compiled and critically evaluated. Examples of application in clinical chemistry, health care, and in the analysis of pharmaceuticals, environmental pollutants, foods and food products are given. The benefits and drawbacks of MS detection are discussed, and future trends are briefly discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Toremifene metabolism in rat, mouse and human liver microsomes: Identification of α‐hydroxytoremifene by LC‐MS
Authors: Jones Russell M. , Lim C. K.
Published: August 2002

The in vitro metabolism of toremifene has been studied in liver microsomal preparations from rat, mouse and human sources using high‐performance liquid chromatography–electrospray ionisation mass spectrometry (HPLC–ESIMS). The metabolites detected were N‐desmethyltoremifene (m/z 392), 4‐hydroxytoremifene (m/z 422), 4′‐hydroxytoremifene (m/z 422) and toremifene N‐oxide m/z 422). In addition, a new polar metabolite with a protonated molecule at m/z 422 has been detected in all three species. The compound was identified by tandem MS‐MS as α‐hydroxytoremifene, an analogue of α‐hydroxytamoxifen. The results showed that α‐hydroxylation is a common feature of tamoxifen and toremifene metabolism and that α‐hydroxytamoxifen is unlikely to be the reactive metabolite responsible for the hepatocarcinogenesis in rat, as widely believed. Copyright © 2002 John Wiley & Sons, Ltd.
Anatomy and physiology of the female perineal body with relevance to obstetrical injury and repair
Authors: Woodman Patrick J. , Graney Daniel O.
Published: August 2002

The female perineal body is a mass of interlocking muscular, fascial, and fibrous components lying between the vagina and anorectum. The perineal body is also an integral attachment point for components of the urinary and fecal continence mechanisms, which are commonly damaged during vaginal childbirth. Repair of injuries to the perineal body caused by spontaneous tears or episiotomy are topics too often neglected in medical education. This review presents the anatomy and physiology of the female perineal body, as well as clinical considerations for pelvic reconstructive surgery. Clin. Anat. 15:321–334, 2002. © 2002 Wiley‐Liss, Inc.
Pathways of anesthetic from the thoracic paravertebral region to the celiac ganglion
Authors: Saito Toshiyuki , Tanuma Kumiko , Den Shulan , Tanuma Yutaka , Miyakawa Kunihisa , Carney Edward , Carlsson Christer
Published: August 2002

Communication between the lower thoracic paravertebral region and the celiac ganglion through the retrocrural space was investigated. After dye was injected into the endothoracic fascia in the lower thoracic paravertebral region at the T11 level, its spread to the celiac ganglion was examined in fifteen cadavers. The dye reached the celiac ganglion in nine cadavers (60%) by passing through the retrocrural space, along the greater and lesser splanchnic nerves and through the split in the crus of the diaphragm through which the splanchnic nerves traveled. In the remaining six cadavers, dye spread toward the ganglion along the crus of the diaphragm. In three living subjects the spread of a radio‐opaque dye injected in the same manner was studied using 3D‐computed tomography. This study confirmed that the radio‐opaque dye traveled toward the celiac ganglion along the crus of the diaphragm. From our results we suggest that a fluid communication may exist between the lower thoracic paravertebral region and the celiac ganglion in cadavers and in living humans and that clinicians should be aware of this possible route of spread when administering lower thoracic paravertebral anesthesia. Clin. Anat. 15:340–344, 2002. © 2002 Wiley‐Liss, Inc.
Brachiocephalic veins: An overlooked approach for central venous catheterization
Authors: Badran D.H. , Abder‐Rahman H. , Abu Ghaida J.
Published: August 2002

Central venous access is important in both assessment and treatment of the patient. In modern clinical practice, a percutaneous approach is preferred. The well‐established subclavian and internal jugular vein catheterization techniques, however, still carry the risk of major acute complications. In this article we describe a trial study of a percutaneous brachiocephalic vein catheterization technique conducted on a total of 74 cadavers undergoing autopsy. Relying on constant and easily recognizable anatomical landmarks, we performed a total of 128 catheterizations of the right and left brachiocephalic veins. The success of catheterization was ascertained by regional dissection. Our results show very high reproducibility with a success rate of about 97% on the first attempt of catheterization on both right and left sides. Equally important, collateral injury of neighboring structures was consistently absent. We propose the introduction of this rather overlooked approach into clinical practice. Clin. Anat. 15:345–350, 2002. © 2002 Wiley‐Liss, Inc.