bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating age of mature adults from the degeneration of the sternal end of the clavicle
Authors: Falys Ceri G. , Prangle Dennis 
Published: October 2014

ABSTRACTThe sternal end of the clavicle has been illustrated to be useful in aging young adults, however, no studies have investigated what age‐related changes occur to the sternal end post epiphyseal fusion. In this study, three morphological features (i.e., surface topography, porosity, and osteophyte formation) were examined and scored using 564 clavicles of individuals of European ancestry (n = 318 males;n = 246 females), with known ages of 40+ years, from four documented skeletal collections: Hamann‐Todd, Pretoria, St. Bride's, and Coimbra. An ordinal scoring method was developed for each of the three traits. Surface topography showed the strongest correlation with age, and composite scores (formed by summing the three separate trait scores) indicated progressive degeneration of the surface with increasing chronological age. Linear regression analyses were performed on the trait scores to produce pooled‐sample age estimation equations. Blind tests of the composite score method and regression formulae on 56 individuals, aged 40+ years, from Christ Church Spitalfields, suggest accuracies of 96.4% for both methods.These preliminary results display the first evidence of the utility of the sternal end of the clavicle in aging older adult individuals. However, in the current format, these criteria should only be applied to individuals already identified as over 40 years in order to refine the age ranges used for advanced age. These findings do suggest the sternal end of the clavicle has potential to aid age estimates beyond the traditional “mature adult” age category (i.e., 46+ years), and provides several suggestions for future research. Am J Phys Anthropol 156:203–214, 2015. © 2014 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.
Breathable properties of m‐Aramid nanofibrous membrane with high thermal resistance
Authors: Park Young Shin , Lee Jong Wha , Nam Young Sik , Park Won Ho 
Published: October 2014

ABSTRACTElectrospinning of m‐aramid in dimethyl acetamide/LiCl solution was investigated to develop thermo‐resistant nanofibrous membranes for breathable waterproof materials. The m‐aramid nanofibers were continuously generated and densely mounted to the membrane without the blockage of the spinning tip during electrospinning. In order to obtain the electrospun m‐aramid nanofibers with different fiber diameters, the polymer concentration in the solution and the spinning distance were varied. Electrospun m‐aramid nanofibrous membranes of various fiber diameters and thicknesses were prepared, and then compared with two commercial expanded polytetrafluoroethylene (ePTFE) membranes with respect to water vapor permeability and pore size. The m‐aramid nanofibrous membrane showed a good water vapor permeability that satisfied the criterion of a breathable membrane, higher than those of the ePTFE porous membranes. Therefore, m‐aramid nanofibrous membrane with thermal and mechanical resistance has great potential for breathable waterproof materials and filters. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41515.
Processing optimization of latex‐compounded montmorillonite/styrene‐butadiene rubber–polybutadiene rubber
Authors: Bao Zuguo , Flanigan Cynthia , Beyer Laura , Tao Jie 
Published: October 2014

ABSTRACTOrgano‐montmorillonite was incorporated into model tire tread formulations through latex compounding methods, to evaluate its effects on elastomer reinforcement and dynamic properties. An intercalation structure was obtained by applying latex compounding method to prepare organoclay‐emulsion stryene butadiene (E‐SBR) masterbatches, for compounding with organoclay loading levels of 0–20 parts per hundred rubber (phr). Microstructure, curing properties and tire performance of the compounded rubber were investigated with the aid of X‐ray diffraction, rheometor and dynamic‐mechanical analysis, respectively. The results showed that organo‐montmorillonite filler provided effective reinforcement in the elastomer matrix, as indicated through mechanical and dynamic mechanical properties. Tread compounds using higher organoclay loadings displayed preferred ice traction, wet traction, and dry handling, but decreased winter traction and rolling resistance. Model compounds using 15 phr of organoclay loading levels were preferred for balanced physical and dynamic properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41521.
Electrochemical synthesis and In situ spectroelectrochemistry of conducting NMPy‐TiO2 and ZnO polymer nanocomposites for Li secondary battery applications
Authors: Arjomandi Jalal , Keramat Irad Mossa Niloofar , Jaleh Babak 
Published: October 2014

ABSTRACTPoly(N‐methylpyrrole) (PNMPy), poly(N‐methylpyrrole‐TiO2) (PNMPy‐TiO2), and poly (N‐methylpyrrole‐ZnO) (PNMPy‐ZnO) nanocomposites were synthesized by in situ electropolymerization for cathode active material of lithium secondary batteries. The charge–discharging behavior of a Li/LiClO4/PNMPy battery was studied and compared with Li/LiClO4/PNMPy‐nanocomposite batteries. The nanocomposites and PNMPy films were characterized by cyclic voltammetry, in situ resistivity measurements, in situ UV–visible, and Fourier transform infra‐red (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The differences between redox couples (ΔE) were obtained for polymer nanocomposites and PNMPy films. During redox scan, a negative shift of potential was observed for polymer nanocomposite films. Significant differences from in situ resistivity of nanocomposites and PNMPy films were obtained. The in situ UV–visible spectra for PNMPy and polymer nanocomposite films show the intermediate spectroscopic behavior between polymer nanocomposites and PNMPy films. The FTIR peaks of polymer nanocomposite films were found to shift to higher wavelengths in PNMPy films. The SEM and TEM micrographs of nanocomposite films show the presence of nanoparticle in PNMPy backbone clearly. The result suggests that the inorganic semiconductor particles were incorporated in organic conducting PNMPy, which consequently modifies the properties and morphology of the film significantly. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41526.
Effect of interfacial area on heterogeneous free radical grafting of vinyl monomers in supercritical carbon dioxide: Grafting of acrylic acid on poly(vinylidenefluoride) nanoparticles
Authors: Lanzalaco Sonia , Scialdone Onofrio , Galia Alessandro 
Published: October 2014

ABSTRACTThe role of the polymer interfacial area on free radical grafting of acrylic acid (AA) onto poly(vinylidenefluoride) (PVDF) was studied at 65°C using supercritical carbon dioxide (scCO2) as a solvent and swelling agent, benzoylperoxide (BPO) as chemical initiator and PVDF nanoparticles as polymer matrix. Under adopted conditions PVDF particles do not melt neither dissolve in the reaction medium and FTIR analyses performed on carefully washed nanoparticles confirmed the achievement of high grafting levels. The mass fraction of grafted AA increased with the grafting time and the BPO concentration while it decreased when the density of the fluid phase was enhanced. Collected results suggest that the grafting level obtained by free radical grafting of vinyl monomers onto solid polymer in scCO2 can be significantly enhanced by increasing the interfacial area of the matrix. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41541.
Fabrication and characterization of novel hyperbranched polyimides with excellent organosolubility, thermal and mechanical properties
Authors: Chen Wenqiu , Li Quantao , Zhang Quanyuan , Xu Zushun , Wang Xianbao , Yi Changfeng 
Published: October 2014

ABSTRACTA series of amine‐terminated and anhydride‐terminated hyperbranched polyimides (HBPIs) were successfully prepared with various commercial dianhydrides and a novel BB′2‐type aromatic triamine, 2,4,6‐tris[4‐(4‐aminophenoxy)phenyl]pyridine, with a symmetrical triaryl‐substituted pyridine segment and prolonged flexible linkages. The chemical structure of the triamine monomer and the hyperbranched structure of the resulting polymers were verified by Fourier transform infrared spectroscopy and 1H‐NMR spectroscopy. The resulting HBPIs, which mainly held an amorphous morphology, exhibited improved organosolubilities in several strong polar aprotic solvents, good heat resistance with glass‐transition temperature values in the range 218.6–311.0°C, and excellent thermal stabilities in both N2 and air [the temperature at 5% weight loss (T5%) in N2 was higher than 529.8°C and the T5% in air was higher than 465.1°C]. The obtained HBPI films also showed outstanding mechanical properties with tensile strength, tensile modulus, and elongation at break values of 86.4–101.3 MPa, 1.73–2.04 GPa, and 5.07–10.67%, respectively; considerable optical transparency; low water absorption; and neutral interface wettability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41544.
Flame‐retardant materials based on phosphorus‐containing polyhedral oligomeric silsesquioxane and bismaleimide/diallylbisphenol a with improved thermal resistance and dielectric properties
Authors: Wang Zheng , Wu Wei , Zhong Yuhua , Ruan Mingzhu , Hui Lin Lin 
Published: October 2014

ABSTRACTPolyhedral oligomeric silsesquioxane containing 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DP) was used to flame‐retard 4,4′‐bismaleimidophenyl methane (BDM)/2,2′‐dially bisphenol A (DBA) resins, and the integrated properties of the resins were investigated. The fire resistance of BDM/DBA resins containing DP was analyzed by limiting oxygen index (LOI) and vertical burning (UL94) tests. The results show that DP increased the LOI of the resins from 25.3 to 38.5%. The BDM/DBA resins were evaluated to have a UL‐94 V‐1 rating, which did not satisfy the high standards of industry. On the other hand, BDM/DBA containing DP achieved a UL‐94 V‐0 rating. The thermal stability and char formation were studied by thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy. TGA and scanning electron microscopy–energy‐dispersive X‐ray spectrometry measurements demonstrated that the DP resulted in an increase in the char yield and the formation of the thermally stable carbonaceous char. The results of Raman spectroscopy showed that the DP enhanced the graphitization degree of the resin during combustion. Moreover, the modified BDM/DBA resins exhibited improved dielectric properties. Specifically, the dielectric constant and loss at 1 MHz of the BDM/DBA/15% DP resin were 3.11 and 0.008, respectively, only about 93 and 73% of those of the BDM/DBA resin. All of the investigations showed that DP was an effective additive for developing high‐performance resins with attractive flame‐retardant and dielectric properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41545.
Electrical conductivity and tensile properties of block‐copolymer‐wrapped single‐walled carbon nanotube/poly(methyl methacrylate) composites
Authors: Ansón‐Casaos Alejandro , Pascual F. Javier , Ruano Cristina , Fernández‐Huerta Natalia , Fernández‐Pato Isaías , Otero Juan C. , Puértolas J. Antonio , Martínez M. Teresa 
Published: October 2014

ABSTRACTPoly(methyl methacrylate) (PMMA) composites containing raw or purified single‐walled carbon nanotubes (SWCNTs) are prepared by in situ polymerization and solution processing. The SWCNTs are purified by centrifugation in a Pluronic surfactant, which consists of polyethyleneoxide and polypropyleneoxide blocks. Both the effects of SWCNT purity and non‐covalent functionalization with Pluronic are evaluated. Electrical conductivity of PMMA increases by 7 orders of magnitude upon the integration of raw or purified SWCNTs. The best electrical properties are measured for composites made of purified SWCNTs and prepared by in situ polymerization. Strains at fracture of the SWCNT/PMMA composites are nearly identical to those of the neat matrix. A certain decrease in the work to fracture is measured, particularly for composites containing purified SWCNTs (−31.6%). Fractography and Raman maps indicate that SWCNT dispersion in the PMMA matrix improves upon the direct addition of Pluronic, while dispersion becomes more difficult in the case of purified SWCNTs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41547.
Evolution of mechanical properties during cure for out‐of‐autoclave carbon‐epoxy prepregs
Authors: Vora Khalil , Vo Tien , Islam Mohammad , Habibi Mohammad , Minaie Bob 
Published: October 2014

ABSTRACTExtent of cure and rheological properties were obtained for out‐of‐autoclave materials, Cycom 5320‐8HS and Cycom 5320‐PW, for the manufacturer recommended cure cycle using differential scanning calorimeter and encapsulated sample rheometer (ESR), respectively. Rheological properties from ESR were further used in designing the cure cycles to study the evolution of mechanical properties. Five panels were cured at different cure stages using the designed cure cycles and coupons were tested for short beam shear and combined loading compression properties at different cure stages. To correlate the mechanical properties with its respective glass transition temperature, dynamic mechanical analyzer was used to obtain the glass transition temperature for the coupons obtained from the respective panels. Statistical results showed significant difference in short beam shear and combined loading compression properties up to vitrification, however, no significant difference was observed on these mechanical properties after vitrification. The observed linear trend between degree of cure (DOC) and glass transition temperature (Tg) was validated using DiBenedetto relation. Linearly increasing trend between DOC and glass transition temperature (Tg) for different cure states suggests that both DOC and Tg can be used interchangeably to define the state of material. A good correlation was observed between material cure state and the mechanical properties. A mathematical model was also proposed to determine the short beam shear and combined loading compression properties based on material cure state. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41548.
Effect of a chain extender on the properties of poly(lactic acid)/zinc oxide/copper chlorophyll acid antibacterial nanocomposites
Authors: Fan Weihua , Zhao Yue , Zhang Aijing , Liu Yukun , Cao Yanxia , Chen Jinzhou 
Published: October 2014

ABSTRACTPoly(lactic acid) (PLA)/nano zinc oxide/copper chlorophyll acid (CCA) antibacterial nanocomposites with excellent mechanical properties were prepared in the presence of a chain extender named tolylene diisocyanate (TDI). The effect of the chain extender on the PLA long chain was confirmed by the increased molecular weight shown in the mass flow rate and gel permeation chromatography. Escherichia coli were adopted to examine the antibacterial ability of the blends. The effect of CCA is also discussed with regard to the enhancement of the antibacterial effect of zinc oxide (ZnO) over E. coli. Scanning electron microscopy and transmission electron microscopy were used to view the agglomeration and dispersion of ZnO in the PLA matrix. Differential scanning calorimetry and thermogravimetric analysis revealed a relatively stable thermal performance of the nanocomposites with and without TDI. A sharp increase in the mechanical properties was also observed after the addition of the chain extender under different processing conditions. Additionally, we found that the nanocomposites with the incorporation of TDI and the masterbatches in batches effectively improved the mechanical properties of PLA/ZnO/CCA without a sacrifice of the antibacterial effect. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41561.
Thiol–norbornene photoclick hydrogels for tissue engineering applications
Authors: Lin Chien‐Chi , Ki Chang Seok , Shih Han 
Published: October 2014

ABSTRACTThiol–norbornene (thiol–ene) photoclick hydrogels have emerged as a diverse material system for tissue engineering applications. These hydrogels are crosslinked through light‐mediated orthogonal reactions between multifunctional norbornene‐modified macromers [e.g., poly(ethylene glycol) (PEG), hyaluronic acid, gelatin] and sulfhydryl‐containing linkers (e.g., dithiothreitol, PEG–dithiol, biscysteine peptides) with a low concentration of photoinitiator. The gelation of thiol–norbornene hydrogels can be initiated by long‐wave UV light or visible light without an additional coinitiator or comonomer. The crosslinking and degradation behaviors of thiol–norbornene hydrogels are controlled through material selections, whereas the biophysical and biochemical properties of the gels are easily and independently tuned because of the orthogonal reactivity between norbornene and the thiol moieties. Uniquely, the crosslinking of step‐growth thiol–norbornene hydrogels is not oxygen‐inhibited; therefore, gelation is much faster and highly cytocompatible compared with chain‐growth polymerized hydrogels with similar gelation conditions. These hydrogels have been prepared as tunable substrates for two‐dimensional cell cultures as microgels and bulk gels for affinity‐based or protease‐sensitive drug delivery, and as scaffolds for three‐dimensional cell encapsulation. Reports from different laboratories have demonstrated the broad utility of thiol–norbornene hydrogels in tissue engineering and regenerative medicine applications, including valvular and vascular tissue engineering, liver and pancreas‐related tissue engineering, neural regeneration, musculoskeletal (bone and cartilage) tissue regeneration, stem cell culture and differentiation, and cancer cell biology. This article provides an up‐to‐date overview on thiol–norbornene hydrogel crosslinking and degradation mechanisms, tunable material properties, and the use of thiol–norbornene hydrogels in drug‐delivery and tissue engineering applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41563.
Polystyrene/attapulgite nanocomposites prepared via in situ suspension polymerization with redox initiation system
Authors: Yang Haicun , Zhang Liu , Ma Wenzhong , Pu Hongting , Gong Fanghong 
Published: October 2014

ABSTRACTA series of polymer–clay nanocomposites consisting of polystyrene (PS) and attapuglite (ATP) were prepared successfully. First, silane coupling agent containing aromatic tertiary amine groups was synthesized to functionalize ATP (M‐ATP). Then, PS nanocomposites with varied clay loadings were prepared via in situ suspension polymerization process with a redox initiation system consisting of aromatic tertiary amine and benzoyl peroxide. The synthesis of silane coupling agent and functionalization of ATP were confirmed by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectra, and X‐ray photoelectron spectroscopy. Mechanical properties, morphology, thermal stability, and rheological behavior of nanocomposites were investigated to illuminate the effects of M‐ATP on the structure and properties of nanocomposites. Field‐emission scanning electron microscope images revealed an ideal dispersion of M‐ATP and an enhanced toughness of nanocomposites. The improved interface interaction between M‐ATP and PS matrix endowed the nanocomposites with outstanding mechanical properties and thermal stability. The formation of hybrid network in the nanocomposites containing 3 wt % M‐ATP resulted in higher complex viscosity (η*), storage modulus (G′), and lower loss factor (tanδ) compared with the pristine PS and PS/ATP nanocomposites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41567.
Solubilization of graphene flakes through covalent modification with well‐defined azido‐terminated poly(ε‐caprolactone)
Authors: Abdullah Nabihah , Hatano Kazuya , Ando Daiki , Kubo Masataka , Koshio Akira , Kokai Fumio 
Published: October 2014

ABSTRACTA well‐defined poly(ε‐caprolactone) (PCL) with terminal azido group was prepared. Grafting‐on reaction between the azido‐terminated PCL (N3PCL) and ultrasonication‐assisted exfoliated graphene flakes (GF) was carried out to obtain PCL‐grafted‐GF (PCL‐g‐GF) which showed good dispersibility in a wide variety of organic solvents. Gel permeation chromatography, 1H NMR, IR, Raman, UV‐vis, and TEM measurements indicated that PCL macromolecules were covalently introduced on the surface of GF without disrupting the structure of GF. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41569.
Synthesis and effects of MDT silicone resin on PMPS‐based ablative composites
Authors: Mu Qiuhong , Peng Dan , Ju Wei , Zhang Fangzhi , Wang Chengguo 
Published: October 2014

ABSTRACTA novel methylphenyl silicone resin, with M, D, and T units, was synthesized by cohydrolysis and cocondensation method from dimethyldimethoxysilane (Me2Si(OMe)2), phenyltrimethoxysilane (PhSi(OMe)3), hexamethyldisiloxane, and 1,3‐divinyl‐1,1,3,3‐tetramethyldisiloxane in toluene/water mixture catalyzed by hydrochloric acid and trifluoromethanesulfonic acid. The vinyl end‐capped MDT silicone resins were chosen for reinforcement filler to enhance the mechanical properties of silicone‐based ablative composites. The effects of resins with various R/Si ratios, vinyl content, and loadings on mechanical properties of PMPS rubbers were investigated. It was revealed that on the premise of good fluidity and processing performance, MDT resin showed excellent reinforcing effect and thermal stability compared with silica. MDT reinforced ablative composite showed satisfactory mechanical and antiablative properties. The linear ablation rate was 0.01 mm/s, which maybe associated with high yield of charred residue in thermogravimetric analysis results. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41571.
pH‐sensitive keratin‐based polymer hydrogel and its controllable drug‐release behavior
Authors: Guo Juhua , Pan Sujuan , Yin Xiaochun , He Yu‐Feng , Li Tao , Wang Rong‐Min 
Published: October 2014

ABSTRACTUsing feather keratin as biocompatible and inexpensive natural biopolymer and methacrylic acid as a functional monomer, we prepared a pH‐sensitive feather‐keratin‐based polymer hydrogel (FKPGel) with grafted copolymerization. The obtained FKPGel was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The swelling behavior and pH sensitivity of the FKPGel were investigated. When the small molecule (rhodamine B) and macromolecule (bovine serum albumin) were used as model drug molecules, the FKPGel exhibited controllable release behavior in vitro, and the hydrogels had pH sensitivity. For a small molecular drug, the cumulative release rate was 97% in 24 h at pH 8.4. For macromolecular drug, the cumulative release rate reached 89% at pH 7.4. Its release behavior could be controlled by the pH value. In summary, a simple method was found to reuse disused feathers. It is a kind of pH‐sensitive hydrogels to be applied in drug‐delivery systems. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41572.