bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of polylactide‐graft‐glycidyl methacrylate graft copolymer and its application as a coupling agent in polylactide/bamboo flour biocomposites
Authors: Xu Tianqiang , Tang Zhaobin , Zhu Jin 
Published: May 2012

AbstractIn this study, a novel graft copolymer, polylactide‐graft‐glycidyl methacrylate (PLA–GMA), was synthesized by the grafting of glycidyl methacrylate onto the polylactide (PLA) chain via free‐radical polymerization. Fourier transform infrared spectroscopy and 1H‐NMR were used to characterize the structure of the copolymer. Furthermore, PLA–GMA was used as a coupling agent to improve the interfacial adhesion between bamboo flour (BF) and PLA in PLA/BF biocomposites. The mechanical properties and crystallization behavior of the PLA/BF biocomposites were investigated. The results show that with the addition of PLA–GMA, the flexural strength and flexural modulus of the biocomposites increased significantly. The mechanical properties increased with increasing PLA–GMA amount. The PLA–GMA also enhanced the crystallization rate of PLA in the PLA/BF biocomposites. The property improvement of the biocomposites was due to enhanced interfacial adhesion between the PLA and BF. This was confirmed by scanning electron microscopy. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012
Fabrication of patterned PDLLA/PCL composite scaffold by electrospinning
Authors: Xu He , Cui Wenguo , Chang Jiang 
Published: May 2012

AbstractFabricating fibrous electrospun scaffolds with controllable fiber‐arrangement have gained an increasing attention in the field of tissue engineering. In this study, the composite patterned D,L‐poly(lactic acid)/poly(ε‐caprolactone) (PDLLA/PCL) scaffolds were fabricated via electrospinning for the first time, and the order degree and contractibility of patterned composite scaffolds with different PDLLA/PCL ratios were further investigated. The results showed that the order degree of the pattern and in vitro shrinkage behaviors of PDLLA/PCL electrospun mats could be finely tuned by controlling blending ratios. The PDLLA/PCL electrospun mats with the ratio 50/50 showed the most balanced properties with controllable pattern structure and appropriate dimensional stability, and they might be a suitable candidate for tissue engineering application. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Catalytic oxidation of polyethylene with oxygen in aqueous dispersion
Authors: Zawadiak Jan , Orlińska Beata , Marek Adam A. 
Published: May 2012

AbstractThe oxidative degradation of polyethylene in aqueous dispersion was studied. The influences of different parameters as well as additives on polyethylene oxidation were investigated. The products obtained in noncatalytic and catalyzed by transition metal salts oxidation processes were compared and characterized by the determination of acid number as well as by means of ICP‐OES, GPC analysis, and FTIR spectroscopy. The obtained results have shown that the catalytic processes using manganese(II) or cobalt(II) acetylacetonate proceeded with two to three times higher rate than process without catalysts. Moreover, the FTIR spectroscopy and GPC analysis confirmed similar properties of final product obtained both in noncatalytic and catalytic processes. Another advantage of this process is a very low content of catalyst in product ∼ 0.001–0.003% of metal used. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Poly(DMAEMA‐co‐PPGMA): Dual‐responsive “reversible” micelles
Authors: Loh Xian Jun 
Published: May 2012

AbstractA series of copolymers with poly(dimethylaminoethyl methacrylate) (P(DMAEMA)), and poly(propylene glycol methacrylate) (PPGMA) segments were synthesized by atom transfer radical polymerization (ATRP) technique. The composition and structural information of the copolymers were studied by gel permeation chromatography (GPC), 1H‐NMR, and TGA. The critical micellization concentrations (CMCs), as well as thermodynamic parameters for micelle formation, of these water‐soluble copolymers were determined at different temperatures. The micelles formed were temperature and pH responsive as determined by lower critical solution temperature (LCST) measurements at different pH environments. At elevated temperatures and low pH, micelles will form with the hydrophobic P(PPGMA) core and the hydrophilic P(DMAEMA) corona. When the temperature is lowered and the pH raised, the morphology of the micelles are “reversed.” In this situation, micelles will form with the hydrophobic P(DMAEMA) core and the hydrophilic P(PPGMA) corona. Preliminary cytotoxicity studies were carried out and showed that these copolymers were nontoxic to cells. These copolymers thus show significant promise for use as a multiresponsive carrier vehicle for the delivery of drugs and other therapeutics to the body. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Radiation degradation of microcrystalline cellulose in solid status
Authors: Sun Jian , Xu Ling , Ge Mengyi , Zhai Maolin 
Published: May 2012

AbstractPulverization and degradation are important pretreatment procedures in producing bio‐ethanol from cellulose. In this study, microcrystalline cellulose (MCC), a pure α‐cellulose, was degraded by γ‐irradiation. The average degree of polymerization, content of reducing sugar, crystalline structure, and molecular structure were investigated to elucidate the radiation effect on the degradation of MCC. The results manifested that γ‐ray destroyed part of the chemical bond and hydrogen bond, leading to the degradation of cellulose and increasing of the reducing sugar content. According to the Fourier transform infrared result, radiation degradation led to the formation of reductive carbonyl group. Meanwhile, radiation had slight influence on the crystalline structures of MCC. Therefore, the radiation degradation procedure is expected to benefit the further proceedings such as ultrafine treatment and enzyme hydrolysis of cellulose. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Removal of nitro aromatic compounds and sulfite acid from distillate of 2,4,6‐trinitrotoluene red water using modified porous polystyrene microspheres
Authors: Meng Qingqiang , Song Kai , Zhao Quanlin , Ye Zhengfang 
Published: May 2012

AbstractTo remove the nitro aromatic compounds (NACs) and SO32− from distillate of 2,4,6‐trinitrotoluene (TNT) red water, the carboxylated and aminated polystyrene (PSt) microspheres were used as adsorbents. GC‐MS and HPLC analysis were used to determine the types and concentrations of NACs before and after adsorption. The carboxylated PSt, which was prepared by modifying PSt with phthlandione (PA), could remove the neutral NACs including 2,6‐dinitrotoluene (2,6‐DNT), 2,4‐dinitrotoluene (2,4‐DNT), 1,3,5‐trinitrobenzene (1,3,5‐TNB), and 2,4,6‐trinitrotoluene (2,4,6‐TNT), with the acid 2,4‐dinitrophenol (2,4‐DNP) and SO32− remained in the distillate. The aminated PSt that was synthesized by activating PSt with chloroacetyl chloride follow by reaction with 1,2‐ethanediamine (EDA) could remove all the NACs and SO32−. The results suggested that EDA‐PSt adsorbed the NACs though multimode interactions, i.e., hydrogen bond and electrostatic attraction. After adsorption using EDA‐PSt, chemical oxygen demand (COD) was reduced from 86.1 to 11.2 mg L−1, and a colorless, transparent, and nontoxic solution with neutral pH value was obtained. Five grams of EDA‐PSt could purify 1600 cm3 of distillate of TNT red water, and the adsorbents could be recycled by elution with methanol to desorb the neutral NACs followed by elution with 0.1 mol L−1 NaOH to wash off 2,4‐DNP and SO32−. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Modeling, prediction, and multifactorial optimization of radiation‐induced grafting of 4‐vinylpyridine onto poly(vinylidene fluoride) films using statistical simulator
Authors: Nasef Mohamed Mahmoud , Shamsaei Ezzatollah , Ghassemi Payman , Aly Amgad Ahmed , Yahaya Abdul Hamid 
Published: May 2012

AbstractThe traditional method for obtaining best combination of reaction parameters for graft copolymerization of 4‐vinylpyridine onto poly(vinylidene fluoride) films was modified using Box‐Behnken factorial design available in the response surface method (RSM). A computer‐assisted statistical simulator was used to obtain the optimum absorbed dose, monomer concentration, grafting time and reaction temperature to achieve the highest degree of grafting (G%) based a quadratic model. The validity of the developed model was confirmed by experimental data, which only deviated by a 2% from the predicted value of G% confirming the effectiveness of RSM in optimization of the reaction parameters in the present grafting system. A comparison was also made between the obtained model and that of 1‐vinylimidazole/poly(ethylene‐co‐tetrafluoroethylene) grafting system. The chemical structure, morphology and thermal stability of the obtained graft copolymers was investigated by means of Fourier transform infrared, filed emission scanning electron microscope, and thermogravimetric analysis, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Ring‐opening metathesis polymerization of bicyclo[2.2.1]hepta‐2,5‐diene (norbornadiene) initiated by new ruthenium(II) complex
Authors: Yalçınkaya Esra Evrim , Dayan Osman , Balcan Mehmet , Güler Çetin 
Published: May 2012

AbstractThe polymerization of norbornadiene (NBD) initiated by a novel ruthenium (Ru)(II) complex (3) containing 1,1′‐pyridine‐2,6‐diylbis[3‐(dimethylamino)prop‐2‐en‐1‐one] (1) as ligand has been investigated. Ru complexes exhibit more catalytic activity in the ring‐opening metathesis polymerization (ROMP) of NBD when activated with trimethylsilyldiazomethane (TMSD). The influence of the various experimental parameters such as reaction time and temperature, nature of the solvent and catalyst, ratio of the NBD/Ru, and TMSD addition has been investigated. The polymers have been obtained in high yields with a relatively low polydispersity index for ROMP and a high
$ \bar M_n $
and
$ \bar M_w $
values in a monomodal distribution. Their structures have been determined by means of FTIR and 1H‐NMR spectroscopy. Thermal properties have been determined via thermogravimetric analysis and DTG methods. The NBD polymerization results that initiated by Ru‐based catalyst coordinated to amine ligand have been compared to initiated by [RuCl2(p‐cymene)]2. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Grafting of maleic anhydride onto polypropylene, in the presence and absence of styrene, for compatibilization of poly(ethylene terephthalate)/(ethylene–propylene) blends
Authors: Bettini Sílvia H. P. , de Mello Lara C. , Muñoz Pablo A. R. , Ruvolo‐Filho Adhemar 
Published: May 2012

AbstractGrafting of polypropylene (PP) by reactive processing in the presence and absence of styrene (ST) was performed to assess the effect of each one of the copolymers obtained in the compatibilization of poly(ethylene terephthalate) and (propylene–ethylene) copolymer blends, PET/EP copolymer (80/20). Grafting reactions of maleic anhydride and ST onto PP were conducted according to an experimental design where the concentrations of maleic anhydride and ST were varied. The amount of reacted maleic anhydride and the extent of degradation in PP were determined by means of Fourier‐transformed infrared spectroscopy and melt‐flow index, respectively. The PET/EP copolymer blends were obtained in a co‐rotating twin‐screw extruder. The effect of grafted copolymer type, PP‐g‐MA (PP grafted with maleic anhydride) or PP‐g‐MAST (PP grafted with maleic anhydride and styrene) in the compatibilization of PET/EP copolymer blends was assessed through mechanical (tensile test), morphological (scanning electron microscopy), and rheological properties. The presence of ST in the grafting reaction of maleic anhydride onto PP showed to significantly increase the amount of reacted maleic anhydride and reduce PP degradation. However, increasing ST concentration in the reaction mass affected the investigated variables only when maleic anhydride concentration was at its lowest level. Results of the PET/EP blends showed that both graft copolymers improved polymer interface adhesion, however, PP‐g‐MAST showed improved performance for the same level of compatibilizer used. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of kraft lignin on protein aggregation, functional, and rheological properties of fish protein‐based material
Authors: Sakunkittiyut Yotsavimon , Kunanopparat Thiranan , Menut Paul , Siriwattanayotin Suwit 
Published: May 2012

AbstractThe main drawbacks of protein‐based bioplastics are a high sensitivity to water, insufficient mechanical properties, and a narrow window of processing conditions. The objective of this work was to study the effect of Kraft lignin (KL) on protein aggregation, functional, and rheological properties of fish protein (FP)‐based bioplastic. FP powder was blended with 30% glycerol and 0–70% KL. Then, blends were thermoformed by compression molding. KL addition increased protein solubility in sodium dodecyl sulfate buffer, indicating a decrease of protein molecular weight. An introduction of KL in protein blend increased mechanical properties and decreased water absorption of materials. KL addition resulted in a decrease in storage modulus in rubbery state of protein blends. It also resulted in a decrease in viscosity of protein blends at processing temperature, as determined by capillary rheometry. Therefore, KL is an alternative additive to enlarge the protein thermal processing window and improve functional properties of FP‐based materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Low methoxylated pectin for preparation of an intelligent functional sheet with responsiveness to sodium ions
Authors: Ichiura Hideaki , Matsuike Tomoko , Ohtani Yoshito 
Published: May 2012

AbstractA functional film is formed on a polyethylene nonwoven sheet by reaction of low methoxylated pectin with calcium chloride (CaCl2) in the presence of ellagic acid. The film contains ellagic acid and functions as an intelligent material by releasing the ellagic acid in the presence of sodium ions. This response results from conversion of the water‐insoluble pectin film to water‐soluble pectin. The film with the best release of ellagic acid is produced using 0.5% CaCl2 and 0.2% water‐soluble pectin solutions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Y:BaZrO3 Perovskite Compounds II: Designing Protonic Conduction by using MD Models
Authors: Cammarata Antonio , Emanuele Antonio , Duca Dario 
Published: May 2012

AbstractThe proton dynamics in Y‐doped BaZrO3 derivatives, in particular the different dopant environments within a Pmm cubic framework, were studied by using classical molecular dynamics (MD) calculations. Single‐ and double substitution of zirconium by yttrium atoms was considered. The presence of yttrium induced variations in the surrounding oxygen sites, according to their local geometrical arrangements. The differences among such distinct oxygen sites became evident when protons interacted with them and upon changes in the temperature. So, different proton transfer pathways, which had different energy barriers, characterized the topologically different oxygen sites. The experimental proton‐hopping activation energy was only reproduced in those structures in which two yttrium atoms formed a Y‐O‐Y arrangement, which also acted as multilevel protonic traps. Protonic conduction in these materials could be improved by avoiding such yttrium clustering, hence preventing the formation of the protonic traps.
Highly Catalytic Carbon Nanotube/Pt Nanohybrid‐Based Transparent Counter Electrode for Efficient Dye‐Sensitized Solar Cells
Authors: Chen Hong‐Yan , Liao Jin‐Yun , Lei Bing‐Xin , Kuang Dai‐Bin , Fang Yueping , Su Cheng‐Yong 
Published: May 2012

AbstractLow‐cost transparent counter electrodes (CEs) for efficient dye‐sensitized solar cells (DSSCs) are prepared by using nanohybrids of carbon nanotube (CNT)‐supported platinum nanoparticles as highly active catalysts. The nanohybrids, synthesized by an ionic‐liquid‐assisted sonochemical method, are directly deposited on either rigid glass or flexible plastic substrates by a facile electrospray method for operation as CEs. Their electrochemical performances are examined by cyclic voltammetry, current density–voltage characteristics, and electrochemical impedance spectroscopy (EIS) measurements. The CNT/Pt hybrid films exhibit high electrocatalytic activity for I−/I3− with a weak dependence on film thickness. A transparent CNT/Pt hybrid CE film about 100 nm thick with a transparency of about 70 % (at 550 nm) can result in a high power conversion efficiency (η) of over 8.5 %, which is comparable to that of pyrolysis platinum‐based DSSCs, but lower cost. Furthermore, DSSC based on flexible CNT/Pt hybrid CE using indium‐doped tin oxide‐coated polyethylene terephthalate as the substrate also exhibits η=8.43 % with Jsc=16.85 mA cm−2, Voc=780 mV, and FF=0.64, and this shows great potential in developing highly efficient flexible DSSCs.
Robust Stability of Time‐Varying Delay Systems: The Quadratic Separation Approach
Authors: Ariba Yassine , Gouaisbaut Frédéric , Johansson Karl Henrik 
Published: May 2012

AbstractIn this article, we are interested in analysing the stability of systems that incorporate time‐varying delays in their dynamic. The Lyapunov‐Krasovskii approach is definitely the most popular method to address this issue and many results have proposed new functionals and enhanced techniques for deriving less conservative stability conditions. In the present work, we propose an original approach: the quadratic separation. To this end, the delay operator properties are exploited to provide delay range stability conditions. In particular, L2‐norm of delay‐dependent operators are computed so as to reduce the conservatism of the approach. Moreover, the main result is able to assess the stability of non‐small delay systems, i.e, it can detect a stability interval for systems that are unstable without any delay. Several examples illustrate the benefit of our methodology.
Finite‐Time Stability and Stabilization of Linear Itô Stochastic Systems with State and Control‐Dependent Noise
Authors: Yan Zhiguo , Zhang Guoshan , Zhang Weihai 
Published: May 2012

AbstractIn this paper, finite‐time stability and stabilization problems for a class of linear stochastic systems are studied. First, a new concept of finite‐time stochastic stability is defined for linear stochastic systems. Then, based on matrix inequalities, some sufficient conditions under which the stochastic systems are finite‐time stochastically stable are given. Subsequently, the finite‐time stochastic stabilization is studied and some sufficient conditions for the existence of a state feedback controller and a dynamic output feedback controller are presented by using a matrix inequality approach. An algorithm is given for solving the matrix inequalities arising from finite‐time stochastic stability (stabilization). Finally, two examples are employed to illustrate the results.
Active red sports car and relaxed purple–blue van: affective qualities predict color appropriateness for car types
Authors: Hanss Daniel , Böhm Gisela , Pfister Hans‐Rüdiger 
Published: May 2012

ABSTRACTResearch suggests that color appropriateness differs as a function of object type. Thus, a color may be perceived as appropriate for one product and inappropriate for another product. We argue that perceived appropriateness depends upon the congruity of the affective qualities of a color with those of the product. This assumption was addressed in two studies in which participants assigned the best matching color out of 13 Munsell colors to each of seven car types. Additionally, affective qualities of both colors and car types were measured on semantic differential scales. The first study showed that color appropriateness varied according to car type. As predicted, the affective qualities of the assigned colors tended to be congruent with the affective qualities of the car types. Affective congruity along the potency dimension of the semantic differential was of particular importance in explaining assignments of colors to car types. The second study was a replication of the first study but with a different sample. The results confirmed what we found in the first study. An interesting difference was, however, that activity (not potency) turned out to be the most important dimension of the semantic differential in explaining assignments of colors to car types. Implications for product development and marketing practice are discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Surprisingly Difficult Resolution of N‐Methylated Cationic [4]Helicenes
Authors: Mehanna Nathalie , Grass Stéphane , Lacour Jérôme 
Published: May 2012

ABSTRACT1,13‐Dimethoxyquinacridinium ions of type 3 are highly configurationally stable [4]helicenes that can be synthesized in racemic form in a single step from tris(2,6‐dimethoxyphenyl)methylium ion. Previously, it had been shown that the single enantiomers can be routinely obtained from racemic mixtures through Pummerer fragmentations of diastereomerically pure sulfoxide adducts that release the enantiopure cations after a C–C bond rupture. This resolution protocol is readily performed because of a (normally) large retention difference of the diastereomers over silica gel. Herein, we report that it is not always the case. Introduction of N‐methyl side chain(s) at the periphery of the helical quinacridinium cations, which are needed for photophysical and biological studies, has a large negative effect of this separation. Instead of simple, rapid, and multigram separations by flash chromatography, extensive semi‐preparative high‐performance liquid chromatography sequences are now required. Chirality 24:928–935, 2012. © 2012 Wiley Periodicals, Inc.
Hearing preservation in patients with unilateral vestibular schwannoma who undergo stereotactic radiosurgery
Authors: Han Jung Ho , Kim Dong Gyu , Chung Hyun‐Tai , Paek Sun Ha , Park Chul‐Kee , Kim Chae‐Yong , Kim Young‐Hoon , Kim Jin Wook , Kim Yong Hwy , Song Sang Woo , Kim In Kyung , Jung Hee‐Won 
Published: May 2012

AbstractBACKGROUND:The objective of this study was to identify the prognostic factors for hearing preservation that would allow the more accurate stratification of patients who undergo stereotactic radiosurgery (SRS) for unilateral, sporadic vestibular schwannoma (VS).METHODS:In total, 119 patients with VS who had serviceable hearing underwent SRS as primary treatment. The mean (±standard deviation) patient age was 48 ± 11 years, and the mean (±standard deviation) follow‐up duration was 55.2 ± 35.7 months. The median marginal radiotherapy dose was 12.0 grays (Gy), and the mean (±standard deviation) tumor volume was 1.95 ± 2.24 cm3. The mean (±standard deviation) pure tone average (PTA) score was 26 ± 12 decibels (dB) (range, 4‐50 dB), and the mean (±standard deviation) maximum speech discrimination score was 91 ± 12% (range, 52‐100%). The mean (±standard deviation) baseline values for the interlatency (IL) of waves I and III (IL I‐III) and the IL of waves I through V (IL I‐V) on auditory brainstem response were 2.58 ± 0.60 milliseconds (mS) (range, 1.92‐4.30 mS) and 4.80 ± 0.61 mS (range, 3.80‐6.40 mS), respectively.RESULTS:In multivariate analysis, the PTA score and IL I‐V were significant and independent prognostic factors (hazard ratio, 1.072; 95% confidence interval, 1.046‐1.098; P < .001; and hazard ratio, 1.534; 95% confidence interval, 1.008‐2.336; P = .046, respectively). By using the PTA score and IL I‐V, the patients were classified into 4 groups. The ratios of patients with serviceable hearing after SRS were 89.6%, 64.0%, 25.8%, and 6.7%, respectively, in Groups A through D (P < .001).CONCLUSIONS:The current results indicated that the classification system based on using the PTA score and the IL I‐V of the auditory brainstem response may be useful and specific for predicting the rate of hearing preservation in each individual. Cancer 2012. © 2012 American Cancer Society.