bluuebunny/crossref_metadata_2025 huggingface dataset:
Clostridium difficile–Associated Disease: An Emerging Threat to Patient Safety: Insights from the Society of Infectious Diseases Pharmacists
Authors: Owens Robert C.
Published: February 2006

A formerly infrequently isolated strain of Clostridium difficile known as BI/NAP1 has resulted in geographically diverse outbreaks of C. difficile – associated disease. Such rapid dissemination and distribution of an outbreak strain of C. difficile are unprecedented, with many regions across North America, as well as several countries in Europe, being affected, all in such a short period of time. Also of note is that nontraditional hosts (e.g., otherwise healthy, noninstitutionalized persons residing in the community, some without antimicrobial exposure) have been reported to have severe disease. Data suggest that certain virulence characteristics may be responsible for more severe clinical presentations and poor outcomes. These factors (e.g., hypertoxin production, hypersporulation, antimicrobial resistance) possessed by a previously uncommon strain of C. difficile, in conjunction with particular host and environmental factors, may have precipitated the now widespread establishment of this pathogen. Antimicrobial intervention has traditionally been a mainstay of combating C. difficile – associated disease. Efforts to combat BI/NAP1 should include good antimicrobial stewardship in addition to effective infection control and environmental intervention.
Modulatory Effects of Atorvastatin on Endothelial Cell–Derived Chemokines, Cytokines, and Angiogenic Factors
Authors: Zineh Issam , Luo Xiaoping , Welder Gregory J. , DeBella Amy E. , Wessel Timothy R. , Arant Christopher B. , Schofield Richard S. , Chegini Nasser
Published: February 2006

Study Objective. To investigate the immunomodulatory effects of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors (statins) by determining whether atorvastatin alters the production of specific endothelium‐derived immunoactive proteins and whether its treatment effects depend on its concentration and/or inhibition of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase.

Design. In vitro study using a multiplexing method for protein measurement.

Setting. University laboratory.

Measurements and Main Results. Human umbilical vein endothelial cells were cultured to approximately 80% confluence and treated with atorvastatin 1–50 μM alone or with mevalonate for 24 hours. Untreated cells served as controls. Culture‐conditioned media were removed and multiplex assayed for protein content of epithelial neutrophil‐activating peptide‐78, interleukin‐8, monocyte chemotactic protein‐1, interleukin‐6, interleukin‐10, fibroblast growth factor, and granulocyte colony‐stimulating factor. Atorvastatin significantly reduced the production of epithelial neutrophil‐activating peptide‐78, interleukin‐6, interleukin‐8, and monocyte chemotactic protein‐1 (p<0.001 to p<0.05) in a concentration‐dependent manner without affecting basal production of interleukin‐10, fibroblast growth factor, and granulocyte colony‐stimulating factor. The treatment effects of atorvastatin were reversed with concurrent mevalonate therapy.

Conclusion: By inhibiting 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase, atorvastatin lowered concentrations of several inflammatory molecules derived from basal‐state endothelial cells in a concentration‐dependent manner. The in vivo importance of these immunomodulatory effects needs further investigation.
Inhibition of Atazanavir Oral Absorption by Lansoprazole Gastric Acid Suppression in Healthy Volunteers
Authors: Tomilo Desiree L. , Smith Patrick F. , Ogundele Abayomi B. , Difrancesco Robin , Berenson Charles S. , Eberhardt Ellana , Bednarczyk Edward , Morse Gene D.
Published: February 2006

Study Objective. To determine whether the pharmacokinetics of atazanavir, a protease inhibitor used to treat human immunodeficiency virus (HIV) infection, are altered by its coadministration with lansoprazole, a proton pump inhibitor.

Design. Single‐dose, open‐label, complete‐crossover study.

Setting. Clinical research center.

Subjects. Ten healthy adult volunteers.

Measurements and Main Results. In phase A, subjects received a single oral dose of atazanavir 400 mg alone. In phase B, the same subjects received oral lansoprazole 60 mg, and after 24 hours they were given a second dose of oral lansoprazole 60 mg with atazanavir 400 mg. Eleven blood samples were collected from each subject over a 24‐hour period for determination of atazanavir plasma concentrations by a validated high‐performance liquid chromatography assay. Pharmacokinetic analysis was performed by standard noncompartmental methods. Nine subjects completed the study, and no significant adverse events were reported. Absorption of atazanavir was significantly reduced when it was coadministered with lansoprazole, as evidenced by a 94% decline in mean area under the concentration‐time curve during the 24 hours after administration (AUC0–24) (p<0.01). The mean ± SD AUC0–24 for phase A was 16.3 ± 9.0 μM•hour versus 0.95 ± 1.8 μM•hour for phase B (p<0.01). The mean ± SD maximum concentration of atazanavir was 3.2 ± 1.7 μM for phase A and 0.13 ± 0.19 μM for phase B (p<0.01).

Conclusion. Acid suppression markedly reduced the bioavailability of atazanavir in this group of healthy volunteers. Based on these results, atazanavir should not be coadministered with lansoprazole or other proton pump inhibitors.
Topiramate for Migraine Prevention
Authors: Wenzel Richard G. , Schwarz Kerry , Padiyara Rosalyn S.
Published: February 2006

Migraine is a costly, recurrent condition that affects 28 million individuals in the United States yet remains underdiagnosed and undertreated. In 2004, the U.S. Food and Drug Administration approved topiramate for the prevention of migraine in adults, joining three other agents with this indication: divalproex sodium, propranolol, and timolol. We evaluated the role of topiramate in the treatment of migraine based on published literature and our clinical experiences. A qualitative systematic search of the literature from January 1966–December 2004 was conducted by using MEDLINE, and other pertinent literature was reviewed. Three large, randomized, placebo‐controlled trials of topiramate for migraine prevention in individuals experiencing 3–12 attacks/month have been published, as have several small studies and a comparator trial with propranolol. Based on the results of these studies, 100 mg/day is the optimum topiramate dosage in terms of efficacy and tolerability. Using that dosage, the number of migraine attacks/month decreased by approximately two. Several other secondary outcome measures were also significantly reduced including the number of days/month with migraine and the use of acute treatment/attack. Suboptimal efficacy was shown with 50 mg/day, whereas 200 mg/day caused considerably more tolerability issues. Paresthesia was dose related and the most common cause of attrition. Cognitive dysfunction and weight loss were also commonly reported. The reduction by two migraines/month demonstrated with topiramate in clinical trials is similar to the published results for other preventive agents, though most of those studies were small, antiquated, and poorly designed. In contrast, the topiramate trials enrolled a larger number of patients and closely adhered to the International Headache Society research recommendations, strengthening the quality of results. Topiramate 100 mg/day is an effective option in adults who require migraine prophylaxis. Although the published efficacy results of the various migraine preventive agents are comparable, the superior study design of the topiramate trials warrants consideration of topiramate as an agent of choice for migraine prevention. Future studies of any preventive agent should include more refined quality‐of‐life outcomes.
Abciximab‐Associated Thrombocytopenia After Previous Tirofiban‐Related Thrombocytopenia
Authors: Dorsch Michael P. , Montague Debbie , Rodgers Jo E. , Patterson Cam
Published: February 2006

A 62‐year‐old man with a history of coronary artery disease and coronary artery bypass graft, chronic heart failure, and peripheral vascular disease required percutaneous coronary intervention (PCI) after progression of shortness of breath and fatigue over 2 years. Four hours after the procedure, the patient developed hematemesis and was found to be thrombocytopenic. The thrombocytopenia was presumed to be due to the abciximab infusion the patient received during and shortly after the PCI. Further review of the patient's medical history revealed that a similar episode had occurred 11 years earlier. At that time, he was enrolled in a clinical trial comparing tirofiban and heparin in patients with unstable angina; he developed profound thrombocytopenia within 24 hours of randomization. After the study unblinding, investigators discovered that the patient received tirofiban, which was thought to be the cause of his thrombocytopenia. Both abciximab and tirofiban are glycoprotein IIb‐IIIa inhibitors, and thrombocytopenia induced by this class of drugs is a serious and potentially life‐threatening adverse reaction. The mechanism is not well understood but has been described as immune mediated with both ligand‐mimetic agents (tirofiban and eptifibatide) and abciximab. Our patient's situation was unusual in that he developed thrombocytopenia from a ligand‐mimetic agent and subsequently had a similar reaction to abciximab. To our knowledge, this case report is the first documentation of thrombocytopenia associated with both tirofiban and abciximab in a single patient, and suggests that care should be given in administering glycoprotein IIb‐IIIa inhibitors of either type to patients with a history of thrombocytopenia due to one of these agents.
Gatifloxacin Interference with Opiate Urine Drug Screen
Authors: Straley Craig M. , Cecil Eric J. , Herriman Mark P.
Published: February 2006

A 48‐year‐old man participating in a residential treatment program was treated with gatifloxacin for a urinary tract infection. While taking the antibiotic, two urine screens were positive for opiates; results of previous urine opiate screens had been negative. Confirmatory tests using a different assay method, however, gave negative results for opiates. Two weeks after completing gatifloxacin therapy, the patient's urine screen was negative for opiates. Application of the Naranjo adverse drug reaction probability scale indicated that gatifloxacin probably was associated with this patient's positive urine opiate screen. Fluoroquinolones as a class are among several compounds that have demonstrated a propensity to cross‐react with enzyme immunoassay urine drug screens for opiates. Occurrence of cross‐reactivity appears to vary among individual assays. The mechanism by which fluoroquinolones cross‐react with the immunoassay is unknown. False‐positive results could have negative effects on patient care, and ramifications of a positive drug screen include possible dismissal from a substance abuse treatment program. Confirmatory analysis using a different assay method is therefore necessary to verify the presence of the target drug.
Synthesis and characterization of aromatic copolyesters containing siloxane linkages in the polymer backbone
Authors: Waghmare P. B. , Idage S. B. , Menon S. K. , Idage B. B.
Published: February 2006

A new series of aromatic copolyesters containing siloxane linkages were prepared by the melt polymerization of bisphenol A (BPA) with eugenol end‐capped siloxane (EuSi), diphenyl terephthalate (DPT), and diphenyl isophthalate (DPI) in varying ratio in the temperature range 220–290°C under reduced pressure in the presence of dibutyl tin dilaurate (DBTL) catalyst. The siloxane copolyesters prepared were characterized by FTIR, 1H‐NMR spectroscopy, solution viscosity, thermogravimetric analysis, differential scanning calorimetry, and X‐ray diffraction. The effect of incorporation of eugenol end‐capped siloxane was studied on the properties of BPA/DPI/DPT copolyesters. The glass‐transition temperature of copolyester was decreased from 184 to 70°C by incorporation of 20% of eugenol end‐capped siloxane. All copolyesters were found to be soluble in commonly used aprotic polar solvents and had film‐forming properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3222–3228, 2006
Dual electroluminescence from a single‐component light‐emitting electrochemical cell, based on water‐soluble conjugated polymer
Authors: Gu Zhen , Shen Qun‐Dong , Zhang Juan , Yang Chang‐Zheng , Bao Yong‐Jun
Published: February 2006

Poly [[2‐methoxy‐5‐(3‐sulfonatopropoxy)‐1, 4‐phenylene]‐1, 2‐ethenediyl] (MPS‐PPV) was an anionic water‐soluble conjugated polymer. A novel single‐component light‐emitting electrochemical cell (LEC) with an indium tin oxide/MPS‐PPV/aluminum sandwich structure has been successfully fabricated. MPS‐PPV serves as both luminescent material and ionic conductor in the active layer. Electroluminescence can be observed under both forward and reverse bias with emission maxima at about 520 nm (green light). In particular, the device has a low turn‐on voltage of about +3V and −4V, and can sustain long‐term operations without much loss of efficiency at ambient conditions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2930–2936, 2006
Fluorescence quantum yield of poly(3‐octylthiophene) upon electrochemical doping
Authors: Danno T. , Kobayashi K. , Tanioka A.
Published: February 2006

The in situ optical absorption and fluorescence of poly(3‐octylthiophene) (POT) upon electrochemical doping were studied. Fluorescence from the undoped POT was observed in the acetonitrile electrolyte. It was quenched by the electrochemical doping. The effect of a dopant molecule on the intensity change of the fluorescence is 7.5 times greater than the one for the optical absorption. Thus, the fluorescence quantum yield decreased after electrochemical doping. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3111–3115, 2006
Investigation of oxygen diffusion into contact lenses using electron spin resonance spectroscopy
Authors: Aydin Emine , Özgür Evrim E. , Özbey Turan , İrkeç Murat , Bozkurt Banu , Kaptan H. Yılmaz
Published: February 2006

Oxygen permeability is the most important parameter of contact lenses, as lack of oxygen causes corneal edema and threatens the vision of the patient. This study was unique in that it used an electron spin resonance (ESR) technique to determine the oxygen diffusion coefficient (D) of contact lenses. Although there are many methods and techniques for investigating oxygen diffusion into contact lenses, ESR was used for the first time in this study. The ESR technique is based on the scavenging of radicals produced in lenses by oxygen. As a contact lens is not a paramagnetic substance, it cannot give an ESR spectrum. But it does produce an ESR spectrum after γ irradiation. When a vacuum‐irradiated contact lens is exposed to air, the radicals trapped in the lens are transformed into peroxide radicals by the addition of molecular oxygen to the free radicals, and the ESR spectrum begins to change with time. This effect can be used as a tool to measure oxygen uptake in irradiated contact lenses. The oxygen diffusion coefficient of a contact lens was determined from changes in ESR signal intensity varying with time. The diffusion coefficients of oxygen for a contact lens were determined for rapid decay [(1.5 + 0.4) × 10−8 cm2/s] and slow decay [(1.3 + 0.3) × 10−9 cm2/s] in this study. These values are in agreement with the D values given in the literature for polymeric materials used for contact lenses. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2937–2941, 2006
Simultaneous interpenetrating polymer networks based on bromoacrylated castor oil polyurethane
Authors: Eren Tarik , Çolak Semra , Küsefoglu Selim H.
Published: February 2006

In the first part of this study, simultaneous addition of bromine and acrylate to the double bonds of castor oil was achieved. In the second part of the study, bromoacrylated castor oil (BACO) was reacted with toluenediisocyanate (TDI), to form a prepolyurethane (BACOP). The prepolyurethanes were reacted with styrene (STY), 2‐hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), and 3‐(acryloxy)‐2‐hydroxy propyl methacrylate (AHPMA) free radically, using the acrylate functional group to prepare the simultaneous interpenetrating polymer networks (SINs). 2,2′‐Azobis (isobutyronitrile) (AIBN) was used as the initiator and diethylene glycol dimethacrylate (DEGDMA) was used as the crosslinker. BACO and BACOP were characterized by IR, 1H‐NMR, and 13C‐NMR techniques. Synthesized polymers were characterized by their resistance to chemical reagents, thermogravimetric analysis, and dynamic mechanical thermal analyzer (DMTA). All the polymers decomposed with 6–10% weight loss in a temperature range of 25–240°C. MMA‐type SIN showed the highest Tg (126°C), while STY‐type SINs showed the highest storage modulus (8.6 × 109 Pa) at room temperature, with respect to other synthesized SINs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2947–2955, 2006
The physical properties of aqueous cationic–nonionic polyurethane with poly(ethylene glycol methyl ether) side chain and its blend with aqueous cationic polyurethane
Authors: Yen Meng‐Shung , Tsai Hsiang‐Chin , Hong Po‐Da
Published: February 2006

The cationic–nonionic dispersing centers with different chain lengths of poly ethylene glycol methyl ether (N‐PDEA 750, N‐PDEA 2000) were prepared from N‐diethanol amine (NDEA), isophorone diisocyanate (IPDI), and poly(ethylene glycol methyl ether) (PEO Mw = 750 and 2000), whereas aqueous cationic–nonionic polyurethane (N‐PDEA PU) with different side chain lengths were prepared by N‐PDEA 750 (or N‐PDEA 2000), 4,4‐methylene bis(isocyantocyclohexane) (H12MDI), polytetramethylene glycol (PTMG 2000), ethylene diamine (EDA), and glycolic acid (GA) as cationic–nonionic dispersing center, hard segment, soft segment, chain extender, and quarternizing agent, respectively. The thermal and mechanical properties of PU casting film were then discussed. We also used N‐methyldiethyolamine (N‐MDEA) without PEO as cationic dispersing center to synthesize aqueous cationic PU (N‐MDEA PU). The PU blends were blending N‐PDEA 750 PU and N‐MDEA PU by different weight ratios and the physical properties of casting films and coated fabric of PU and PU blends were investigated. Regarding the thermal properties, we have found out that the cationic–nonionic PU (N‐PDEA 750 PU, N‐PDEA 2000 PU) has lower Tgs, Tms, TmH, and ΔHH than N‐MDEA PU, apart from ΔHs. The N‐PDEA 2000 PU with longer side‐chain PEO has lower Tgs, higher Tms and ΔHs than N‐PDEA 750 PU. As for mechanical property, N‐PDEA PU has lower tensile strength of casting film compared with N‐MDEA PU. Regarding the comparison of side chain length of PEO, N‐PDEA 2000 PU with longer side chain has higher tensile strength than N‐PDEA 750 PU with shorter side chain length. In addition, N‐PDEA 2000 PU group that shows hard property in stress–strain curve, whereas N‐PDEA 750 PU shows soft property. The tensile strength of PU blends decreases as the content of N‐PDEA 750 PU increases. When the low‐blend ratio of N‐PDEA 750 PU (e.g., 5%), the tensile strength of casting film only shows less influence that can improve the elongation effectively. In terms of coating‐treated fabrics, cationic–nonionic PU‐coated fabrics show lower waterproof capacity (WP) than those treated by cationic PU. However, the water vapor permeability (WVP) and antiyellowing of the N‐PDEA 750 PU coated fabrics are significantly better than the one treated by cationic polyurethane. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2963–2974, 2006
Flow through diffusion cell method: A novel approach to study in vitro enzymatic degradation of a starch‐based ternary semi‐interpenetrating network for gastrointestinal drug delivery
Authors: Bajpai S. K. , Saxena Sutanjay
Published: February 2006

A ter‐polymeric semi‐IPN has been synthesized by aqueous polymerization of methacrylamide in the presence of polyethylene glycol (PEG) and natural polysaccharides starch, and its enzymatic degradation has been studied in the phosphate buffer medium of pH 6.8 at the physiological temperature 37°C. With the increase in content of enzyme in the external solution and starch in the hydrogel, the degradation is enhanced while the extent of degradation is lowered with the increase in the amount of PEG in the hydrogel. The initial water content also affects the degradability of the polymer matrix. The degradation follows Michaelis–Menten kinetics and KM was found to be 3.92 × 10−5 mol dm−3. The hydrogel exhibits different degradation behavior when studied by “traditional degradation method” (TDM) and “flow through diffusion cell” (FTDC) method. The degradability is suppressed in FTDC method because of the absorption of amylase molecules onto filler particles. Finally the nature and size of the filler particles also affects the degradation behavior of hydrogels. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2975–2984, 2006
Synthesis and characterization of biodegradable polyethylene by graft copolymerization of starch using glucose–Ce(IV) redox system
Authors: Maharana T. , Singh B. C.
Published: February 2006

Graft copolymerization of low‐density polyethylene (LDPE) onto starch was carried out with glucose–cerium(IV) redox initiator in an aqueous sulfuric acid medium under nitrogen atmosphere. The graft yield was influenced by various parameters like reaction time, temperature, and concentrations of acid, glucose, polyethylene (PE), starch, and initiator. A maximum graft yield of 85.66% was obtained at a temperature of 50°C and at higher concentration of starch. Effect of grafting on crystallinity, morphology, and thermal properties of modified PE has been evaluated using X‐ray diffraction, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA/DTA). Biodegradability of starch‐grafted PE has been tested applying soil‐burial test. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3229–3239, 2006
Effect of weathering cycle and manufacturing method on performance of wood flour and high‐density polyethylene composites
Authors: Stark Nicole M.
Published: February 2006

Wood–plastic lumber is promoted as a low‐maintenance high‐durability product. When exposed to accelerated weathering, however, wood–plastic composites may experience a color change and loss in mechanical properties. Differences in weathering cycle and composite surface characteristics can affect the rate and amount of change caused by weathering. In this study, 50% wood flour filled high‐density polyethylene composite samples were injection molded, extruded, or extruded and then planed to remove the manufacturing surface characteristics. Composites were exposed to two accelerated weathering cycles in a xenon arc weathering apparatus. This apparatus exposed the samples to xenon arc radiation, which is a combination of UV, visible, and IR radiation that is similar to solar radiation. Composites were exposed to radiation with or without water spray. After exposure to radiation and water spray, composites with more wood component at the surface (i.e., planed samples) experienced a larger percentage of total loss in flexural modulus of elasticity and strength after weathering compared with the other composites. Composites exposed to radiation only did not experience as much change in properties as those exposed to radiation with water spray. The results of this study demonstrate that exposing wood–plastic composites to water spray in combination with radiation is more severe than exposing wood–plastic composites to radiation only. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3131–3140, 2006
Linear viscoelastic properties of HFPE‐II‐52 polyimide
Authors: Antonakakis J. N. , Bhargava P. , Chuang K. C. , Zehnder A. T.
Published: February 2006

The polyimide HFPE‐II‐52 was developed at NASA Glenn Research Center for use as a matrix in high temperature composite materials. The unique properties of such composites stem largely from the performance of the matrix at high temperature. Thus, as part of a larger effort to study high temperature composite materials, the linear viscoelastic properties of HFPE are measured and a mathematical model of the properties is developed. In particular, storage, loss, and stress relaxation moduli were obtained from cyclic and transient loading experiments. A Prony series was fit to the relaxation modulus data. As a cross check, the fit to the relaxation modulus was converted to storage and loss moduli and compared with those measured directly. Effects of postcuring and of moisture on the properties are investigated as well. These results provide researchers with a constitutive model for HFPE‐II‐52 and provide some insight into the performance of HFPE matrix composites at high temperatures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3255–3263, 2006
Determination of impurities in industrial caprolactam produced from toluene by SPME and GC–MS
Authors: Li Na , Zou Jiankai
Published: February 2006

Solid‐phase microextraction (SPME) in combination with gas chromatography‐mass spectrometry (GC–MS) was applied to study the impurities in industrial caprolactam produced from toluene. Various nitriles, lactones, amides, and alcohols were detected to be the main impurities in caprolactam products. Trace amounts of heterocyclic compounds, which had great effects on the quality of caprolactam, were also successfully detected. Those were pyrrole, 2‐ethyl‐3‐methyl pyrazine, 5,6,7,8‐tetrahydroquinoxaline, quinoxaline, 2,3‐dimethyl quinoxaline, 2‐pyridinamide, etc. The effects of some impurities on caprolactam quality and the polymerization of caprolactam as well as the possible origin of the main impurities were also discussed. This could be of great importance to the industrial purity control of caprolactam. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3141–3144, 2006
Acetylation of cellulose using recyclable polymeric catalysts
Authors: Luo Jie , Sun Yuyu
Published: February 2006

The esterification of cellulose with acetyl chloride in N‐methyl‐2‐pyrrolidinone proceeded smoothly using crosslinked polyvinylpyridine (C‐PVP) as catalysts. The structures of the cellulose acetates were confirmed by FTIR, 1H‐NMR, and 13C‐NMR analyses. The molecular weights were determined by GPC, and the thermal properties were characterized with DSC and TGA. The effects of reaction conditions on yields and degree of substitutions were evaluated in detail. C‐PVP was recycled by a simple alkali treatment, and the recycled C‐PVP could be readily reused as catalysts in cellulose acetylations without adverse effects on the reactions. The influences of C‐PVP on the structures of cellulose acetate samples were further discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3288–3296, 2006
Effect of porosigen and hydrophobic monomer on the fast swelling–deswelling behaviors for the porous thermoreversible copolymeric hydrogels
Authors: Lee Wen‐Fu , Yeh Yu‐Chen
Published: February 2006

A series of porous thermoreversible copolymeric hydrogels were prepared from N‐isopropylacrylamide (NIPAAm) and hydrophobic monomers such as 2,2,3,3,4,4,5,5‐octafluoropentyl methacrylate (OFPMA) and n‐butyl methacrylate (BMA) and CaCO3 or poly(ethylene glycol) 8000 (PEG8000) as porosigen by emulsion polymerization. The effect of hydrophobic monomers and porosigens on the fundamental properties, such as equilibrium swelling ratio, swelling kinetics, gel strength, crosslinked densities, etc., and fast swelling–deswelling behavior for the present copolymeric hydrogels were investigated. Results showed that the deswelling rates for the gels porosigened by CaCO3 were more rapid than those gels foamed by PEG8000. Results also showed that the swelling rates for the gel foamed by CaCO3 were higher than those for the gel foamed by PEG8000. At the same time, results also showed that the gels with OFPMA foamed by CaCO3 exhibit a faster swelling–deswelling behavior than those gels with BMA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3152–3160, 2006
Calorimetric study of the system clorhydrate of chitosan/glutaraldehyde(1,5‐pentanedial)
Authors: Fraga F. , Blanco J. , Luzardo A. , Leira L. , Rodríguez‐Núñez E. , Martínez‐Ageitos J. M. , Castro‐Díaz C.
Published: February 2006

The reaction of glutaraldehyde with primary amino groups of chitosan produces covalent crosslinking in a matricial microsphere formulation. The influence of the crosslinking times on the calorimetric parameters (glass transition temperatures, enthalpy, and endothermic peak) of the system clorhydrate of chitosan/glutaraldehyde (1,5‐pentanedial) was studied using differential scanning calorimetry in dynamic mode. Using Kissinger′s method, the activation energies for the water remaining process were obtained without a precise knowledge of the reaction mechanism from the experimental endothermic peaks. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3297–3301, 2006
Dyeing properties of PECH‐amine cationized cotton with acid dyes
Authors: Rong Li , Feng Gu
Published: February 2006

The dyeing properties of cationic cotton dyed with acid dyes are examined in this study. For comparison, nylon 6 and untreated cotton are dyed by the same acid dyes (Sandolan Red MF‐2BL, Sandolan Golden Yellow MF‐GL, and Sandolan Blue MF‐GL). A cationic agent, polyepichlorohydrin‐dimethylamine (PECH‐amine), is used to modify cotton fabric. Significant increase in color yield is observed for cationic cotton over untreated cotton because of the introduced positively charged sites by cationic modification. Deeper shades are obtained in all cases with cationic cotton. All of the acid dyes used in this study show significant hooking behavior with both cationic cotton and nylon. © 2006 Wiley Periodicals, Inc. J Appl Polym Polym Sci 100: 3302–3306, 2006
Damping properties of chlorinated polyethylene‐based hybrids: Effect of organic additives
Authors: Zhang Cheng , Wang Ping , Ma Chun‐an , Sumita Masao
Published: February 2006

In this article, the damping properties of organic hybrids consisting of chlorinated polyethylene (CPE), N,N‐dicyclohexyl‐2‐benzothia‐zolylsufenamide (DZ), and 4,4′‐thio‐bis(3‐methyl‐6‐tert‐butylphenol) (BPSR) have been investigated by dynamic mechanical analysis (DMA). It is found that DZ and BPSR seem to have a synergistic effect on the damping improvement of CPE/DZ/BPSR hybrids. For CPE/DZ/BPSR three‐component hybrids, when BPSR content is below 20 wt %, the values of damping peak maximum are just the same, while the damping peak position shifts to a higher temperature at a higher BPSR concentration. When BPSR content is fixed at 10 wt %, the damping peak maximum increases with increasing DZ/CPE ratio, while there is little shift in the peak position within the ratio range of 0.75–1.25. The decrease in damping peak maximum against annealing can be attributed to the phase separation resulting from the crystallization of hybrids components. Such a crystalline phase, which has been formed during annealing, contains not only pure DZ crystallites but also some CPE–DZ or CPE–DZ–BPSR eutectic crystals. Furthermore, the damping stability of the hybrids can be improved excellently by adding a small amount of BPSR or changing hot‐pressing temperature. These may imply that a series of high‐performance damping materials possessing both high damping peak maximum and controllable damping peak position can be achieved. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3307–3311, 2006
Synthesis of new anionic HTPB‐based polyurethane elastomers: Aqueous dispersion and physical properties
Authors: Poussard Loïc , Burel Fabrice , Couvercelle Jean‐Pierre , Loutelier‐Bourhis Corinne , Bunel Claude
Published: February 2006

New segmented polyurethane (PU) anionomers based on hydroxytelechelic polybutadiene (HTPB) were synthesized via an environment‐friendly chemical route. Incorporation of carboxylated functions on the PU soft segment was carried out using a thiol‐ene reaction on HTPB vinyl double bonds with thioglycolic acid. PU water dispersions were obtained by addition of a water dispersible polyisocyanate, i.e., Bayhydur® 3100, to the modified ionic HTPB water dispersions. The key factor of this formulation is the control of ionic concentration apart from the hard segment content, oppositely to all other PU anionomer formulations. The influence of ionic content was studied through all steps of the PU material synthesis, from aqueous dispersions upto crosslinked materials' physical properties. For fully neutralized precursors, the stability of the ionic aqueous dispersions was higher than that was in six months. In all cases, particles were smaller than 200 nm. PU glass transition temperature, surface hydrophily and swelling increased with ionic content. But, however, PUs exhibit hydrophobic surface properties with a maximum surface tension of 45 mN m−1 and a limited water uptake. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3312–3322, 2006
Effects of spinning conditions on structure and properties of multifunctional fibers of polyimidoamide nanocomposites
Authors: Mikołajczyk Teresa , Olejnik Magdalena
Published: February 2006

The effects of basic fiber‐forming parameters on the porous structure, moisture absorption, and strength properties of fibers from polyimidoamide nanocomposites were examined. Beneficial fiber‐forming conditions were established in consideration of the fiber sorption and strength properties. It was found that the incorporation of montmorillonite into the fiber‐forming polymer resulted in beneficial increases in fiber porosity and internal surface area. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3323–3331, 2006
Aging and moisture effects on the tensile properties of starch/poly(hydroxyester ether) composites
Authors: Lawton J. W. , Doane W. M. , Willett J. L.
Published: February 2006

The effects of starch and aging on the mechanical properties of starch/poly(hydroxyester ether) (PHEE) composite materials were characterized. Native or modified cornstarches were extruded with PHEE. Composites were aged for up to 20 months at either 23°C and 50% relative humidity (RH) or over calcium sulfate to keep the composites dry. The tensile strength (TS) of the composites was affected by the type of starch filler that they contained. Composites containing native or crosslinked starch had significantly greater TS than composites containing octenylsuccinated starch. It was thought that the octenylsuccinate modification of the starch granule affected the adhesion between the starch and PHEE. Aging the composites at 50% RH had a significant effect on the mechanical properties of the composites, with TS and Young's modulus (YM) significantly decreasing and the elongation to break significantly increasing after 20 months of storage. Composites stored at 50% RH absorbed water, which caused changes in the mechanical properties by plasticizing PHEE. Composites containing poly(lactic acid) and PHEE did not experience large reduction in TS and YM when aged at 50% RH, even though they also absorbed water. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3332–3339, 2006
Reactive blending of modified polypropylene and polyamide 12: Effects of compatibilizer content on crystallization and blend morphology
Authors: Wu Yang , Yang Yuming , Li Binyao , Han Yanchun
Published: February 2006

The crystallization behavior and morphology of nonreactive and reactive melt‐mixed blends of polypropylene (PP) and polyamide (PA12; as the dispersed phase) were investigated. It was found that the crystallization behavior and the size of the PA12 particles were dependent on the content of the compatibilizer (maleic anhydride–modified polypropylene) because an in situ reaction occurred between the maleic anhydride groups of the compatibilizer and the amide end groups of PA12. When the amount of compatibilizer was more than 4%, the PA12 did not crystallize at temperatures typical for bulk crystallization. These finely dispersed PA12 particles crystallized coincidently with the PP phase. The changes in domain size with compatibilizer content were consistent with Wu's theory. These investigations showed that crystallization of the dispersed phase could not be explained solely by the size of the dispersion. The interfacial tension between the polymeric components in the blends may yield information on the fractionation of crystallization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3187–3192, 2006
Relationship between the thermal degradation chemistry and flammability of commercial flexible polyurethane foams
Authors: Denecker C. , Liggat J. J. , Snape C. E.
Published: February 2006

In this article, we report the use of a variety of analytical methods, in particular, solid‐state 1H‐NMR and 13C‐NMR to characterize the relationship between the condensed‐phase chemistry and burning behavior as determined by a series of combustion tests for two commercially derived flexible polyurethane foams, one combustion‐modified. The combustion tests showed that the foams met several regulatory requirements in terms of their fire performance, whether or not they were combustion‐modified. Both foams passed the MV SS 302 and CAL 117 small‐flame tests. The nonmodified foam failed the Crib 5 test, but this test had a much larger ignition source. The particular problem with the nonmodified foam was melt drip into the flame zone. This led to a steady maintenance of the fuel feed and a rapid escalation of the fire. In contrast, the combustion‐modified foam showed little melt drip and self‐extinguished. Thermal analysis data for the two foams showed that melamine acted in part as an endothermic heat sink. This alone did not account for the much reduced melt flow and drip of the combustion‐modified foam, but the solid‐state 1H‐NMR data clearly showed that the molecular mobility of the combustion char from combustion‐modified foam was lower than the unmodified foam char, which indicated that the flame‐retardant formulation in the combustion‐modified foam acted by a condensed‐phase mechanism. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3024–3033, 2006
Effect of exfoliation and dispersion on the yield behavior of melt‐compounded polyethylene–montmorillonite nanocomposites
Authors: Truss Rowan W. , Yeow Tay Kiah
Published: February 2006

The yield behavior of melt‐mixed nanocomposites containing 5 wt % organically modified montmorillonite in matrices of a linear low‐density polyethylene (LLDPE) or a modified polyethylene was studied as a function of the temperature and strain rate. In the melt‐mixed LLDPE nanocomposite, the montmorillonite showed a slight increase in the clay spacing, which suggested that the clay was at best intercalated. Transmission electron microscopy (TEM) images showed that the dispersion in this nanocomposite was poor. The use of the modified polyethylene promoted exfoliation of the clay tactoids in the nanocomposite, as assessed by X‐ray diffraction and TEM. In both nanocomposites, the yield mechanisms were insensitive to the addition of the organoclay, even though modest increases in the modulus were produced. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3044–3049, 2006
Fourier transform infrared and wide‐angle X‐ray diffraction studies of the thermal cyclization reactions of high‐molar‐mass poly(acrylonitrile‐co‐itaconic acid)
Authors: Devasia Renjith , Nair C. P. Reghunadhan , Sadhana R , Babu N. S. , Ninan K. N.
Published: February 2006

The stabilization reactions of a high‐molar‐mass poly(acrylonitrile‐co‐itaconic acid) precursor in air at 200, 220, and 240°C were studied with Fourier transform infrared. Principally, the cyclization of nitrile groups leading to the ladder structures of tetrahydropyridine occurred. Evidence for oxidative reactions causing the conversion of the CC structure to CC and generating groups such as OH and CO was also obtained. As the temperature of stabilization was increased, the rate of the reaction increased without causing great changes in the Fourier transform infrared spectral patterns. The maximum nitrile conversion achievable was limited by the temperature of stabilization. Although the reaction stagnated at 40 and 80% at 200 and 220°C, it was practically complete in about an hour at 240°C. Higher temperatures also favored the formation of extended conjugated structures. Wide‐angle X‐ray diffraction studies of the polymer stabilized at 300 and 400°C in argon confirmed that the aromatization index value and the crystallinity of the polymer increased proportionally to the temperature of pyrolysis. An analysis of the wide‐angle X‐ray diffraction pattern and the elemental composition of the stabilized polymer implied the formation of the tetrahydropyridine structure at 400°C. The higher pyrolysis temperature favored the formation of the lattice constituted by this group. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3055–3062, 2006
Modification of the polarity and adhesive properties of polyolefins through blending with maleic anhydride grafted Fischer–Tropsch paraffin wax
Authors: Novák I. , Krupa I. , Luyt A. S.
Published: February 2006

The modification of the polarity and adhesive properties of linear low‐density polyethylene, low‐density polyethylene, and isotactic polypropylene through blending with paraffin wax (Fischer–Tropsch synthesis), grafted by maleic anhydride, was investigated. Maleic anhydride grafted paraffin wax significantly increased the polar component of the total surface free energy of polyolefins. Modified polyolefins also had significantly higher adhesion to the polar substrate, a crosslinked, epoxy‐based resin. The conservation of the good mechanical properties of the blends was observed up to 10 wt % wax, except for isotactic polypropylene blends, for which there was a reduction in the stress and strain at break at wax concentrations higher than 5%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3069–3074, 2006
Morphology–toughness correlation of polypropylene/ethylene–propylene rubber blends
Authors: Kotter Ines , Grellmann Wolfgang , Koch Thomas , Seidler Sabine
Published: February 2006

A polypropylene homopolymer was blended with ethylene–propylene rubber in different mixing ratios. The influence of the ethylene–propylene rubber content on the toughness behavior was investigated. According to the results of instrumented impact tests, brittle‐to‐tough transition temperatures were found for different ethylene–propylene rubber contents. Critical transition temperatures could be determined not only in the region of predominantly unstable crack propagation but also in the region of stable crack initiation. In situ measurements provided information on the deformation processes on the crack tip. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3364–3371, 2006
Thermally stable and organosoluble cardo binaphthylene based poly(amide imide)s and poly(ester imide)s
Authors: Behniafar Hossein , Jafari Ashkan
Published: February 2006

A new imide‐containing dicarboxylic acid based on a twisted binaphthylene unit, 2,2′‐bis(N‐trimellitoyl)‐1,1′‐binaphthyl (1), was synthesized from 1,1′‐binaphthyl‐2,2′‐diamine and trimellitic anhydride in glacial acetic acid. The structure of compound 1 was fully characterized with spectroscopic methods and elemental analysis. Series of thermally stable and organosoluble poly(amide imide)s (4a–4d) and poly(ester imide)s (5a–5d) with similar backbones were prepared by the triphenyl phosphite and diphenylchlorophosphate activated direct polycondensation of diimide dicarboxylic acid 1 with various aromatic diamines and diols, respectively. With due attention to the structural similarity of the resulting poly(amide imide)s and poly(ester imide)s, most of the differences between these two block copolyimides could be easily attributed to the presence of alternate amide or ester linkages accompanied by imide groups in the polymer backbone. The ultraviolet maximum wavelength values of the yellowish polymers were determined from their ultraviolet spectra. The crystallinity of these copolyimides was estimated by means of wide‐angle X‐ray diffraction, and the resultant polymers exhibited a nearly amorphous nature, except for the polymers derived from benzidine and 4,4′‐binaphthol. The poly(amide imide)s exhibited excellent solubility in a variety of highly polar aprotic solvents, whereas the poly(ester imide)s showed good solubility in less polar solvents. According to differential scanning calorimetry analyses, polymers 4a–4d and 5a–5d had glass‐transition temperatures between 331 and 357°C and between 318 and 342°C, respectively. The thermal behaviors of the obtained polymers were characterized by thermogravimetric analysis, and the 10% weight loss temperatures of the poly(amide imide)s and poly(ester imide)s were between 579 and 604°C and between 566 and 577°C in nitrogen, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3203–3211, 2006
Mechanical properties and transparency of injection‐molded polyacetal with branched and linear structure: Influence of crystalline morphology
Authors: Kawaguchi Kuniaki
Published: February 2006

Branched and linear polyacetals prepared by cationic bulk polymerization were molded under high‐injection rate and pressure, and the resultant 1‐mm‐thick specimens were investigated regarding the crystalline morphology, mechanical properties, and transparency. The branched polyacetal exhibited shear‐induced transformation of crystalline morphology, namely, the spherulites, the elongated spherulites, and shish‐kebab morphology parallel to the flow direction, with increasing shear viscosity. The degree of orientation of the branched polyacetal, calculated from the intensity distribution on the Debye ring of the (100) diffraction by WAXS, linearly and significantly increased with the increase of the logarithm of the shear viscosity. The difference of the crystalline morphology greatly influenced the mechanical properties and transparency of the branched and linear polyacetals. The branched polyacetal with the shish‐kebab morphology had approximately 20% higher tensile strength and modulus as compared with those with the spherulites morphology, and showed translucent with a higher light transmittance over a wide range of wavelength of incident light. The results indicate that a large number of fibrous crystals in the shish‐kebab morphology result in the self‐reinforcement of specimens parallel to the flow direction and diminishment of the scattering of incident light. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3182–3392, 2006
Improvement of bond strength of BPDA‐PDA‐type polyimide film by corona discharge treatment
Authors: Ogawa Toshio , Baba Shigenori , Fujii Yuichiro
Published: February 2006

Aromatic polyimide film composed of biphenyl tetracarboxylic acid dianhydride (BPDA) and p‐phenylene diamine (PDA) is a very stable polymer at high temperatures and very useful for the electronics industry. Bonding properties were improved by corona discharge treatment of this film. The chemical modification method was applied for generated functional groups, that is, carboxylic, hydroxyl, and amino groups in the gas phase, and the quantity of these functional groups was determined by X‐ray photoelectron spectroscopy. The functional groups increased with corona energy, leveling off at a specific corona energy. The bond strength of the copper foil/adhesive/polyimide film was determined. The relationship between bond strength and functional group content was analyzed by multivariate analysis. Bond strength could be sufficiently correlated with functional group quantity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3403–3408, 2006