bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of curing cycles on curing reactions and properties of a ternary system based on benzoxazine, epoxy resin, and imidazole
Authors: Wang Hongyuan , Zhao Pei , Ling Hong , Ran Qichao , Gu Yi 
Published: May 2012

AbstractA ternary blend (BEM) of benzoxazine (BA‐a), epoxy resin (E44), and imidazole (M) was prepared to study the effect of different curing cycles on curing reactions and properties of cured resins. Reactivity of two binary blends, E44 and BA‐a, with the catalyst M, was first investigated based on the curing kinetics. Results suggest that E44/M has lower reaction activation energy than BA‐a/M meaning the reaction of E44/M easily proceeds. To further figure out the sequences of the curing reactions of E44, BA‐a, and M in BEM, the curing behaviors of three BEM gels at 80, 140, and 180°C (defined as BEM‐80g, BEM‐140g, and BEM‐180g) were studied by DSC and FTIR techniques. For BEM‐80g, E44/M cured before BA‐a/M. For BEM‐180g, both curing reactions occurred simultaneously and the copolymerization of BA‐a and E44 was promoted. The crosslinked structures of cured BEM with different initial curing temperatures were strongly influenced by the reaction sequences. The Tgs, flexural properties and thermal stability of the copolymers with different curing cycles were compared. Good performance of this ternary system can be obtained by choosing suitable curing cycles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
A recycling model of excess toluene diisocyanate isomers in the preparation of polyurethane prepolymer
Authors: He Yong , Zhang Xinya , Zhang Xinfang , Huang Hong , Chang Jie , Chen Huanqin 
Published: May 2012

AbstractReaction kinetics of dropwise addition of trimethylolpropane (TMP) to toluene diisocyanate (TDI‐80) at various temperatures and initial stoichiometry was studied. The progress of the polymerization reaction was monitored by measuring the concentration of isocyanate groups and TDI isomers by means of backtitration and high performance liquid chromatography (HPLC), respectively. The kinetics of dropwise addition method, compared with the conventional one‐shot method, was well described by a second order equation. This procedure was optimized by comparing the deviations between experimental data and theoretically calculated data. The effects of temperature, initial stoichiometry and TDI isomers on the amount of excess 2,4‐TDI and 2,6‐TDI were investigated. Three commercially available TDI mixtures, 65 : 35, 80 : 20, and 100 : 0 ratio of 2,4‐TDI/2,6‐TDI, respectively, were used. A recycling model of unreacted TDI isomers and solvent was established to reach a stable process and yield polyurethane prepolymer with good reproducibility. This model has been applied in the chemical plant to prepare polyurethane prepolymer with precisely defined chemical compositions in a continuous process. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Fabrication and in vitro investigation of nanohydroxyapatite, chitosan, poly(L‐lactic acid) ternary biocomposite
Authors: Zhang C. Y. , Zhang C. L. , Wang J. F. , Lu C. H. , Zhuang Z. , Wang X. P. , Fang Q. F. 
Published: May 2012

AbstractThe nanohydroxyapatite/chitosan/poly(L‐lactic acid) (HA/CS/PLLA) ternary biocomposites were prepared by blending the hydroxyapatite/chitosan (HA/CS) nanocomposites with poly(L‐lactic acid) (PLLA) solution. Surface modification by grafting D‐, L‐lactic acid onto the HA/CS nanocomposites was designed to improve the bonding with PLLA. The FTIR and 13C‐NMR spectrum confirmed that the oligo(lactic acid) was successfully grafted onto the HA/CS nanocomposites, and the time‐dependent phase monitoring showed that the grafted copolymers were stable. The TEM morphology of the HA/CS/PLLA ternary nanocomposites showed that nano‐HA fibers were distributed homogeneously, compacted closely and wrapped tightly by the CS and PLLA matrix. The ternary biocomposites with the HA content of 60 and 67 wt % exhibited high compressive strength of about 160 MPa and suitable hydrophilicity. The in vitro tests exhibited that the ternary biocomposites have good biodegradability and bioactivity when immersed in SBF solutions. All the results suggested that the n‐HA/CS/PLLA ternary biocomposites are appropriate to application as bone substitute in bone tissue engineering. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Dispersion of nanoclays with poly(ethylene terephthalate) by melt blending and solid state polymerization
Authors: Kim Sung‐Gi , Lofgren Elizabeth A. , Jabarin Saleh A. 
Published: May 2012

AbstractMelt intercalation of clay with poly(ethylene terephthalate; PET) was investigated in terms of PET chain mobilities, natures of clay modifiers, their affinities with PET, and nanocomposite solid state polymerization (SSP). Twin screw extrusion was used to melt blend PET resins with intrinsic viscosities of 0.48, 0.63, and 0.74 dL/g with organically modified Cloisite 10A, 15A, and 30B montmorillonite clays. Clay addition caused significant molecular weight reductions in the extruded PET nanocomposites. Rates of SSP decreased and crystallization rates increased in the presence of clay particles. Cloisite 15A blends showed no basal spacing changes, whereas the basal spacings of Cloisite 10A and Cloisite 30B nanocomposites increased after melt extrusion, indicating the presence of intercalated nanostructures. After SSP these nanocomposites also exhibited new lower angle X‐ray diffraction peaks, indicating further expansion of their basal spacings. Greatest changes were seen for nanocomposites prepared from the lowest molecular weight PET and Cloisite 30B, indicating its greater affinity with PET and that shorter more mobile PET chains were better able to enter its galleries and increase basal spacing. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Simultaneous interpenetrating network silicone hydrogels prepared by free radical/cationic hybrid polymerization
Authors: Wang Jing Jing , Liu Fang 
Published: May 2012

AbstractSimultaneous interpenetrating polymer network silicone hydrogels have been prepared by UV‐initiated polymerization of a mixture of methacrylate monomer 2‐methacryloyloxyethyl phosphorylcholine (MPC) and vinyl ether terminated polydimethylsiloxane (VESi) macromonomer. The consumption of each (macro)monomer upon UV‐irradiation was monitored in situ by real‐time infrared spectroscopy. The methacrylate monomer MPC was shown to polymerize faster and more extensively than the vinyl ether terminated macromonomer VESi. Curing experiments performed in the presence of air and under air diffusion‐free conditions indicated that the free radical polymerization of MPC was affected by the oxygen inhibition effect, while the cationic polymerization of VESi was influenced by the atmosphere humidity. The results of the transmission electron microscope studies indicated that the silicone hydrogels were heterogeneous with phase domain sizes less than 10 nm. The physicochemical properties of the silicone hydrogels, such as water content, ion permeability, oxygen permeability, and contact angle were also investigated. The results showed that water content and ion permeability increased with the MPC content in the formulation, and the silicone hydrogels exhibited excellent oxygen permeability with the highest Dk of 255 barrer. The contact angle measurements indicated that the silicone hydrogels possessed hydrophilic surfaces with the lowest water contact angle of 20°. The result of the protein resistance revealed that the amount of protein adsorbed was significantly reduced with the MPC content in the formulation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Influence of natural and accelerated weathering on performances of photoselective greenhouse films
Authors: Russo Pietro , Acierno Domenico , Marinucci Luca , Greco Antonio , Frigione Mariaenrica 
Published: May 2012

AbstractThe research aims to investigate the effects of natural and accelerated weathering on polyethylene‐based films. At this regard, monolayer films of low density/linear low density polyethylene blends, containing commercially available organic pigments and an UV absorber of the benzophenone type, have been considered. The samples were weathered on field (natural weathering) or using two different artificial procedures: UV lamp and QUV chamber. Conditioned film samples were, then, analyzed by performing several physical tests taking as‐received films as a reference. Rheological measurements showed an increase in viscosity of weathered sample melts as a consequence of photodegradation phenomena, inducing the formation of double bonds and crosslinks. This latter result was also confirmed by gel content measurements. UV–visible spectroscopic tests indicated that in both cases of natural and artificial weathering an increase of the transmittance of films occurred. Tensile tests indicated the increase of films stiffness, especially in case of samples conditioned using the UV lamp, and a large decrease of the strain at break, both in machine and in transverse directions, especially for film weathered using the QUV chamber. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Nerve guidance channels based on PLLA–PTMC biomaterial
Authors: Wach Radoslaw A. , Adamus Agnieszka , Olejnik Alicja K. , Dzierzawska Joanna , Rosiak Janusz M. 
Published: May 2012

AbstractBiodegradable polymers of poly(lactic acid) (PLLA) and synthesized in‐house poly(trimethylene carbonate) (PTMC) with admixture of water‐soluble methyl cellulose (MC) were used for development of nerve guidance tubes for peripheral nervous system regeneration after injury. Fabrication method involved phase separation of viscous dixane solution of polymers mixture seat on a rod in a proper nonsolvent, which resulted in tubular structure of large porosity. Influence of electron beam sterilization on molecular weight, thermal properties of the polymers, and mechanical performance of the tubes was evaluated. Admixture of hydrophilic MC to synthetic polymers resulted in modification of mechanical properties of the channels. Extraction of MC showed potential of the tubes for releasing water‐soluble bioactive molecules, such as for instance growth factors. Basic in vitro MTT and LDH assays showed no cytotoxic effect of manufactured tubes, therefore, animal experimentations may be considered. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Superporous collagen‐sericin scaffolds
Authors: Lungu Adriana , Albu Madalina G. , Stancu Izabela Cristina , Florea Nicoleta M. , Vasile Eugeniu , Iovu Horia 
Published: May 2012

AbstractSuperporous materials based on two proteins, collagen and sericin were synthesized by freeze‐drying considering various ratios between the two proteins. To evaluate the influence of sericin content on the structure/properties relationship, the obtained scaffolds were further characterized using spectroscopic analysis, thermal, and mechanical techniques. Scanning electron microscopy was used to investigate the morphological structure of the scaffolds and the swelling properties as well as the stability of the scaffolds were also assessed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Applicability of Wu's criterion for brittle–ductile transition of ethylene/1‐octene copolymer toughened polyamide 6
Authors: Hu Yuexin , Feng Yulin , Jiang Yang , Yin Jinghua , Jiang Wei 
Published: May 2012

AbstractThe brittle–ductile transition of ethylene/1‐octene copolymer (POE) toughened polyamide 6 (PA6) was studied at various temperatures. The experimental results show that the critical interparticle distance (IDc) is independent of the POE content, and the POE particle size at lower temperatures, that is, the temperature is much lower than the brittle–ductile transition temperature (T) of PA6. At higher temperatures, however, especially temperatures close to the T, the IDc depends on the POE particle size. This indicates that Wu's criterion for rubber toughening, specifically that “the IDc is a material property of the matrix, independent of rubber volume fraction and particle size,” is inapplicable at higher temperatures for the brittle–ductile transition of the POE toughened PA6. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The preparation and characterization of hydrophilic macroporous foams from water soluble polymers grafted ultra‐high molecular weight polyethylene
Authors: Aydinli Bahattin , Tincer Teoman 
Published: May 2012

AbstractMacroporous foams of water soluble polymers grafted ultra‐high molecular weight polyethylene (UHMWPE) were obtained by precipitation of hot xylene gel solutions in ethyl alcohol. The water soluble monomers used for grafting were acrylic acid (AA), methacrylic acid (MAA), acrylamide (AAm), N‐vinylpyrrolidone (NVP), and N‐N‐di‐methyl acrylamide (NNDAm). The morphology of the foams was investigated using the scanning electron microscope (SEM). Significant changes in the morphology and pore size were observed among the foams depending upon the type of grafting water soluble polymers. The porosity of the foams was uniform and varied from 1 to 10 μm. The percentages of the free volume and water uptake of the foams were measured. The foams obtained from grafted UHMWPE had an appreciable water uptake capacity and water could pass through them compared with the water repelling pure UHMWPE foams. The poly(NNDAm)‐grafted UHMWPE yielded markedly better foams than the others. The water soluble polymer‐grafted conventional polymers posses the characteristics of hybrid material where hydrophobic and mechanically strong UHMWPE make up a strong backbone and hydrophilic hydrogel affords biocompatibility. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The Viability of Perilabyrinthine Osteocytes: A Quantitative Study Using Bulk‐Stained Undecalcified Human Temporal Bones
Authors: Bloch Sune Land , Kristensen Søren Lund , Sørensen Mads Sølvsten 
Published: May 2012

AbstractBone remodeling is highly inhibited around the inner ear space, most likely by the anti‐resorptive action of the inner ear cytokine osteoprotegerin (OPG) entering perilabyrinthine bone through the lacuno‐canalicular porosity (LCP). This extracellular signaling pathway depends on the viability of individual osteocytes. The objective of this study was to evaluate the patency of the LCP at different ages. Sixty‐five bulk‐stained undecalcified human temporal bones and 19 ribs were selected to span the ages from the 30th gestational week to 95 years. Osteocytes from inside a 2‐mm wide perilabyrinthine zone of bone were identified by 3D vector calculations and the numerical densities estimated with an optical dissector and compared to age‐matched ribs. From a high fetal count of 90,000 cells/mm3, the density of viable capsular osteocytes declined rapidly to 73,000 cells/mm3 at three years of age, and non‐viable osteocytes increased inversely. After 3 years, this decline/increase continued at a much slower rate. The densities of viable as well as non‐viable osteocytes and the rates of change were much higher in perilabyrinthine bone compared to ribs. Only after the age of 80 years had the density of viable capsular osteocytes declined to the level of ribs. The bi‐phasic osteocyte kinetics reflects different development stages. The high initial density of viable osteocytes may secure a life‐long anatomical route for inner‐ear OPG despite the unique accumulation of non‐viable osteocytes. Clustering of non‐viable osteocytes may cause local aberrations in the signaling system by closure of the LCP. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Are old males still good males and can females tell the difference?
Authors: Johnson Sheri L. , Gemmell Neil J. 
Published: May 2012

AbstractSperm function generally declines with male age. Paradoxically, females of many species still choose to mate with old males rather than young males. Females choosing old mates may suffer reduced fertilization rates and an increased incidence of birth defects in offspring, lowering fitness which may in turn lead to conflict between the sexes. This apparent paradox has generated much interest from theorists, but whether this paradox presents in nature remains equivocal. Empirical studies have found mixed support for both a decline in fertility with male age and age‐based female mate preference. Here, we examine recent evidence for this paradox, identify confounding variables, highlight areas that deserve further investigation, and suggest avenues for future research.
A chemiluminescence sensor array based on nanomaterials for discrimination of teas
Authors: Niu Weifen 
Published: May 2012

ABSTRACTIn recent years, electronic tongue and nose devices have been developed that consist of an array of cross‐responsive sensors. In this study, we report a chemiluminescence (CL) sensor array based on oxidation at twelve different catalytic nanomaterial locations for the discrimination of eight teas. CL response patterns or “fingerprints” were obtained for a given compound on the sensor array and then discriminated through linear discriminant analysis. The experiments demonstrate that the sensor array had excellent differentiability and reversibility. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis and luminescence properties of 2‐(benzylcarbamoyl)phenyl derivatives and their europium complexes
Authors: Guo Dongcai , He Wei , Liu Bang , Gou Lining , Li Ruixia 
Published: May 2012

ABSTRACTSix novel 2‐(benzylcarbamoyl)phenyl derivatives were synthesized and characterized by 1H‐NMR, mass spectrometry, infrared spectra and elemental analysis. Their europium complexes were prepared and characterized by elemental analysis, EDTA titrimetric analysis, IR and UV spectra as well as molar conductivity measurements. The luminescence properties of these complexes were investigated and results show that 2‐(benzylcarbamoyl)phenyl derivatives possess high selectivity and good coordination with the europium ion. Complex Eu‐2‐(benzylcarbamoyl)phenyl‐2‐phenylacetate showed green luminescence that was emitted by the ligand of 2‐(benzylcarbamoyl)phenyl‐2‐phenylacetate, while other complexes showed the characteristic red luminescence of europium ion and also possessed high luminescence intensity. Copyright © 2012 John Wiley & Sons, Ltd.
The normative and conceptual foundations of a clinical duty to protect
Authors: Quattrocchi Michael R. , Schopp Robert F. 
Published: May 2012

AbstractThe continuing controversy surrounding the Tarasoff inspired duty to protect as developed by the courts and legislatures has not adequately weighed the jurisprudential foundations of such an obligation. The authors argue that the duty's misguided thrust of social control grounded in character and status seriously violates broad principles of political morality underlying the law of social control. They conceptualize an alternative—a clinical duty to protect—that coheres with these underlying values and the limits of professional abilities. They contend that any extra‐clinical intervention on the part of the psychotherapist entails a role transformation requiring independent justification.
Child abuse and the limits of confidentiality: Forewarning practices
Authors: Crenshaw Wesley B. , Lichtenberg James W. 
Published: May 2012

AbstractConfidentiality is widely considered to be of great importance in psychotherapy. With few exceptions, the breaching of confidentiality is an ethical violation and grounds for litigation. One such exception is the mandated reporting of known or suspected child abuse, representing a legally sanctioned limitation of confidentiality. Because clients generally expect unlimited confidentiality in therapeutic relationships, many therapists have begun to “forewarn” clients as a matter of informed consent. This research report: (a) briefly reviews issues surrounding mandatory reporting and confidentiality as they relate to forewarning, (b) defines and discusses forewarning as contrasted with “informing,” (c) examines state statutes, case law and ethical guidelines relevant to forewarning, and (d) presents a survey of 428 mental health providers (MHPs) on their forewarning practices in which 36.9% forewarned all clients, 36.4% informed clients only upon suspicion of abuse, and 20.6% informed only after receiving a disclosure of abuse. The implications of these findings are discussed.
A philosophical examination of coercion for mental health issues
Authors: Wertheimer Alan 
Published: May 2012

AbstractThis article considers two philosophical questions about coercion and mental disorders: (1) an analytical question, i.e., what is meant by the concept of coercion? (2) a normative question, i.e., what justifies the use of coercion? The article distinguishes between coercion from other forms of power such as inducement, persuasion, and authority. It then considers a range of arguments for the paternalistic use of coercion for the benefit of mentally disordered persons and the use of coercion to restrain mentally disordered dangerous persons.This article rests on the assumption that there is something to be said for an academic division of labour, that empirical research in mental health and the law can benefit from conceptual clarification and the analysis of normative arguments. In this article I distinguish between two importantly different sorts of questions that we can ask about coercion and then offer some answers to those questions in broad strokes.
Coercive interactions in a psychiatric emergency room
Authors: Lidz Charles W. , Mulvey Edward P. , Arnold Robert P. , Bennett Nancy S. , Kirsch Brenda L. 
Published: May 2012

AbstractThis paper describes the prevalence of coercive and non‐coercive efforts to influence patients' admission decisions in a psychiatric emergency room. The findings are based on previously collected transcripts of the interaction between patients and families and emergency room staff in 405 cases. Although a significant percentage of the patients were involuntarily admitted, otherwise the most prominent pressures were efforts by attending physicians to persuade patients about what would be the most appropriate disposition. However, a detailed qualitative analysis of the interaction suggest that the clinical staffs power to commit patients against their will affects the way all parties interpret the staffs ‘persuasion’ in such a way that it may be understood as quite coercive.
Inclusion, motivation, and good faith: The morality of coercion in mental hospital admission
Authors: Bennett Nancy S. , Lidz Charles W. , Monahan John , Mulvey Edward P. , Hoge Steven K. , Roth Loren H. , Gardner William 
Published: May 2012

AbstractWe administered a semi‐structured interview to 157 patients shortly after their admission to a psychiatric hospital. In the first, and open‐ended, part of the interview, patients were asked to talk about what had been going on in their lives that led to their coming into the hospital. Then, in a more structured format, they were asked more specific details about who was involved, the patients' relationships with those involved, whether any attempts were made to influence the patient to come into the hospital, and whether such attempts were perceived as fair by the patient.This article presents a qualitative review of the transcripts of a subset of these interviews. It attends specifically to patients' perceptions of the morality of attempts by others—primarily family members, friends and mental health professionals—to influence them to be admitted to the hospital, and of the morality of the process by which these influence attempts resulted in admission.