bluuebunny/crossref_metadata_2025_split huggingface dataset:
Angle‐resolved light scattering from textured injection‐molded plastics
Authors: Ignell Sofie , Rigdahl Mikael 
Published: October 2011

AbstractWith regard to surface appearance, the angle‐resolved light scattering from textured polymeric surfaces was evaluated to link the reflectance properties to measured gloss as well as visually perceived gloss. Bidirectional reflectance distributions were determined by means of a scatterometer and the specimens involved were textured injection‐molded plaques manufactured from three different polymers; an acrylonitrile‐butadiene‐styrene (ABS) copolymer, a polypropylene (PP), and a polycarbonate and ABS copolymer blend (PC/ABS). The influence of color, surface roughness, and angle of incidence on the scattering characteristics was evaluated. An off‐specular reflectance peak was observed for the textured specimens the magnitude of which was clearly determined by the surface roughness and the angle of incidence. The color of the specimens mainly influenced the diffuse reflectance. The results provide a measure of perceived gloss and supported previously reported findings regarding the relevance of the concept of contrast gloss for the gloss characterization of textured polymeric surfaces. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Influence of clay content on the melting behavior and crystal structure of nonisothermal crystallized poly(L‐lactic acid)/nanocomposites
Authors: Ublekov F. , Baldrian J. , Kratochvil J. , Steinhart M. , Nedkov E. 
Published: October 2011

AbstractTo study the effect of organophilic clay concentration on nonisothermal crystallization, poly(L‐lactic acid) (PLLA)/montmorillonite (MMT) nanocomposites were prepared by mixing various amounts of commercial MMT (Cloisite® 30B) and PLLA. The effect of MMT content on melting behavior and crystal structure of nonisothermal crystallized PLLA/MMT nanocomposites was investigated by differential scanning calorimetry (DSC), small‐angle X‐ray scattering, and wide‐angle X‐ray diffraction (XRD) analyses. The study was focused on the effect of the filler concentration on thermal and structural properties of the nonisothermally crystallized nanocomposite PLLA/MMT. The results obtained have shown that at filler loadings higher than 3 wt %, intercalation of the clay is observed. At lower clay concentrations (1–3 wt %), exfoliation predominates. DSC and XRD analysis data show that the crystallinity of PLLA/MMT composites increases drastically at high clay loadings (5–9 wt %). In these nanocomposites, PLLA crystallizes nonisothermally in an orthorhombic crystal structure, assigned to the α form of PLLA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of pellet size and compatibilization on thermal decomposition kinetic of recycled polyethylene terephthalate/recycled polypropylene blend
Authors: Thumsorn Supaphorn , Yamada Kazushi , Wei Leong Yew , Hamada Hiroyuki 
Published: October 2011

AbstractThis study considers the effects of pellet geometry and compatibilization on its moisture absorption and thermal degradation behavior of recycled polyethylene terephthalate (RPET) and recycled polypropylene (RPP) blend with the ultimate goal of optimizing the design of pellets to enhance their processability. The isoconversion of Flynn–Wall–Ozawa (FWO) was used for the kinetic study, which was suitable for thermal degradation of RPET/RPP blend in N2 while the second order polynomial function was fitted for thermal oxidative degradation in air. Finer geometries, such as powders, were found to have higher moisture absorption rates due to their large surface area although they could also be easily dried. Furthermore, large surface area of fine powder as well as good interaction between RPP disperse particles and RPET matrix eased to decompose in the presence of oxygen thus accelerated chain breaking during thermal oxidative degradation especially at low heating rate. Meanwhile, larger pellets exhibited higher degradation activation energies, which suggest that they are more resistant to thermal degradation than smaller grains. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Weathering of low‐density polyethylene grafted with itaconic acid in laboratory tests
Authors: Wojtala Anna , Czaja Krystyna , Sudoł Marek , Semeniuk Izabela 
Published: October 2011

AbstractPolyethylene grafted with itaconic acid was subjected to weathering under laboratory accelerated conditions. The course of the photo‐oxidative degradation process of that material was studied by FTIR spectroscopy both through quantitative measurements of changes in absorbance values at selected wave numbers and through measurements of surface area values for absorption bands which were separated by means of deconvolution. The use of both those procedures of quantitative determinations resulted in a general conclusion that the oxidation process was initiated from the very first moment of irradiation, and it produced ketones, acids, esters (intramolecular and of acetate type), peracids, peresters, hydroperoxides, and alcohols. The molecular weight values and gel number values, which were established as well, pointed out that oxidation was accompanied by cracking of polymer macromolecules, and also by polymer crosslinking to a limited degree. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of molecular weight of an anionic dispersant on the properties of BaTi4O9 slurries
Authors: Chung Tzu‐Min , Hsu Kung‐Chung 
Published: October 2011

AbstractThe colloidal stability of BaTi4O9 (BT4) aqueous suspensions with poly(acrylamide‐co‐4‐carboxylamino‐4‐oxo‐2‐butenate) (PAC) of different molecular weights at pH 9 has been investigated by means of zeta potential, adsorption, sedimentation, and particle size measurements. The results indicate that PAC could improve the dispersion of the particles from agglomeration. The resulting suspensions became more stabilized, and contained powder with smaller particle size. Consequently, the compacts with PAC exhibited better properties in terms of density and dielectric constant than those without any polymer present. The performance of PAC increased with decreasing polymer molecular weight. Clearly, PAC1 (Mw = 1.8 × 104) was most effective in dispersing the BT4 particles, and stabilizing the ceramic suspensions. This is attributed to the highest adsorption of this polymer onto BT4 powder, and causes strongest electrostatic repulsions among solid particles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and characterization of novel polyimides containing triazoles units in the main chain by click chemistry
Authors: Hajipour Abdol R. , Abrishami Fatemeh 
Published: October 2011

AbstractIn this study, some polyimides containing triazoles units in the main chain was prepared from the polymerization of dialkynes including imide linkages and diazides in the presence of Cu (I) catalyst in yield of 76.2–87.6%, with inherent viscosity of 0.37–0.53 dL g−1. The obtained polymers are soluble in polar aprotic solvents such as N,N‐dimethyformamide (DMF), N,N‐dimethyacetamide (DMAc), dimethyl sulfoxide (DMSO), and N‐methyl‐2‐pyrrolidone (NMP). These polymers were characterized using FT‐IR, 1H‐NMR, and elemental analysis techniques. Their thermal stability was evaluated with thermogravimetric (TGA) analysis and differential scanning calorimetry (DSC) techniques under a nitrogen atmosphere which is indicative of their good thermal stability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of poly(1,2‐propylene glycol adipate) and nano‐CaCO3 on DOP migration and mechanical properties of flexible PVC
Authors: Li Xihong , Xiao Yao , Wang Biao , Tang Yao , Lu Yaqing , Wang Chengjun 
Published: October 2011

AbstractNano‐CaCO3 was used as nano‐scale filler and poly(1,2‐propylene glycol adipate) (PPA) was used as polymeric plasticizer in flexible poly(vinyl chloride) (PVC) sheets for the partial replacement of di(2‐ethyl hexyl) phthalate (DOP) in this paper. The effect of PPA and nano‐CaCO3 on restraining DOP migration was evaluated via extraction tests. The results showed that the introduction of nano‐CaCO3 can decrease the extraction rate of DOP in the PVC matrix. The tensile strength and elongation at break of CaCO3‐1/PPA‐20/DOP‐30/PVC were similar to those of DOP‐50/PVC, and CaCO3‐1/PPA‐20/DOP‐30/PVC exhibited the superior suppression of DOP migration compared with DOP‐50/PVC. Thermogravimetry analysis (TGA) indicated that the addition of nano‐CaCO3 effectively improved the thermal stability of the nanocomposites. Therefore, the combination of PPA and nano‐CaCO3 is an effective approach to suppress the migration of DOP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Characterization of soybean protein concentrate—stearic acid/palmitic acid blend edible films
Authors: de la Caba K. , Peña C. , Ciannamea E. M. , Stefani P. M. , Mondragon I. , Ruseckaite R. A. 
Published: October 2011

AbstractThe effect of incorporating commercial stearic acid/palmitic acid blend (SA/PA, 63/37 wt %) into hydrophilic soybean protein concentrate (SPC) film‐forming solutions at neutral and alkaline pH on some selected properties of edible cast films was investigated. SA/PA‐added SPC film exhibited a significant increase in translucency, being more relevant for films obtained at pH 7. This was associated with the more heterogeneous morphology of such films as observed by scanning electron microscopy. Calorimetric measurements and X‐ray diffraction studies confirmed the presence of crystalline fatty acids in films at pH 7 and new crystalline structures at pH 10 due to interactions or reactions between SPC and SA/PA blend. Fourier Transform infrared spectroscopy results confirmed the incorporation of fatty acids into SPC and revealed the occurrence of interactions between both components, depending on the film‐forming emulsion pH. Moisture absorption isotherms at high relative humidity (RH) were determined and experimental data were adequately fitted by Peleg's empirical equation. Control SPC films produced at pH 7 were distinctly more moisture resistant than those at pH 10 owing to the more charged protein molecules at alkaline pH. The increased moisture resistance of SA/PA‐added‐SPC film at pH 10 was related to the more homogeneous dispersion of fatty acid particles within the protein matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Chemical synthesis, characterization, and properties of conducting copolymers of imidazole and pyridine
Authors: Raj V. , Madheswari D. , Mubarak Ali M. 
Published: October 2011

AbstractA series of conducting copolymers were synthesized by chemical oxidative polymerization of imidazole (Imi) and pyridine (Py) in acetonitrile medium at ambient temperature. The yield, solubility, and conductivity of the copolymers were measured by changing the Imi/Py molar ratio from 0/100 to 100/0. The as‐prepared Imi/Py conducting copolymers were characterized by UV‐Visible, FTIR, 1H‐NMR, DSC, TGA, and XRD. The results suggest that the resulting copolymers were more easily soluble in most of the organic solvents than in polyimidazole. The polymer obtained is a real copolymer containing imidazole and pyridine units, but the Imi content calculated on the basis of the proton NMR spectra is lower than feed Imi content. The thermostability of the Imi/Py copolymer increases with increasing Imi unit content. The copolymers show comparatively higher conductivity and higher thermal stability than the homopolymer polypyridine and are lower than those of polyimidazole. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Temperature and time dependence of electrical resistivity in an anisotropically conductive polymer composite with in situ conductive microfibrils
Authors: Zhang Yi‐Chuan , Dai Kun , Pang Huan , Luo Qiao‐Ji , Li Zhong‐Ming , Zhang Wei‐Qin 
Published: October 2011

AbstractAn anisotropically conductive polymer composite (ACPC) based on conductive carbon black (CB) and binary polymer blend of polyethylene (PE) and polyethylene terephthalate (PET) was successfully fabricated under shear and elongational flow fields. The PET phase formed in situ the aligned conductive microfibrils whose surfaces were coated by CB particles. This ACPC material exhibited a strong electrical anisotropy within a broad temperature range. When the ACPC samples were subjected to isothermal treatment (IT), they showed anomalous variations of the positive temperature coefficient (PTC) and negative temperature coefficient (NTC) effects. The PTC intensity was attenuated gradually with the increase of the IT time, and the NTC intensity was nearly eliminated after IT of 8 or 16 h. Beyond 16 h, the resistivity in the NTC region rose anomalously with the temperature after the elimination of NTC effect, which was the result of much transformation from the potential pathways to the intrinsic pathways due to the disordering of oriented conductive microfibrils. When the amount of potential pathways was very small, the effect of the intrinsic pathway separation surmounts that of the potential pathways, leading to the anomalous resistivity increase in the NTC region. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Selective sorption of Fe(III) using modified forms of chitosan beads
Authors: Gandhi Muniyappan Rajiv , Kousalya G. N. , Meenakshi S. 
Published: October 2011

AbstractModified chitosan beads (CB) were prepared and used for the removal of Fe(III) ions from aqueous solution. The advantages of modified CB than raw CB have been explored. The sorption capacity (SC) of the modified forms of CB namely, protonated CB, carboxylated CB, and grafted CB were found to be 3533, 3905, and 4203 mg kg−1, respectively, while the raw CB showed the SC of 2913 mg kg−1 only. Batch adsorption studies were conducted to optimize various equilibrating conditions like contact time, pH, and coions. The sorbents were characterized by FTIR, WDXRF, and SEM with EDAX analysis. The sorption process has been explained with Freundlich and Langmuir isotherms. Thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were calculated to understand the nature of sorption. Modified CB are more selective for Fe(III) than Cu(II), which inturn higher than Cr(VI). A suitable mechanism for iron sorption onto modified CB was established. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The effect of synthesis condition on physical properties of epoxy‐containing microcapsules
Authors: Wang Rongguo , Hu Honglin , Liu Wenbo , He Xiaodong , Guo Qiong 
Published: October 2011

AbstractThe physical properties of microcapsules are largely influenced by the synthesis conditions such as weight ratio of core/shell material, agitation rate, reaction time, and different emulsifier. Different synthesis condition would lead to different property. It is an important issue for application in composites that require self‐healing microcapsules possessing rough surface morphology, less adhesion, less core material permeability, appropriate diameter and core content, and adequate shell thickness. The properties of microcapsules influenced by the synthesis conditions were investigated systematically in this article. According to orthographic factorial design, the most influencing factor on microcapsule's yield, core material, average shell thickness and average diameter, are concluded, respectively. The synthesis parameters when the epoxy‐containing microcapsules exhibit the optimum properties are concluded: 1.4 : 1 for the weight ratio of core/shell material, 250 rpm for the agitation rate, 3 h for the reaction time and 1.5% content for the emulsifier DBS. The chemical structure of resultant microcapsules is confirmed by FT‐IR, and core material of microcapsule exhibits reactivity through DSC measurement. Subsequently, the microcapsules are characterized by SEM, OM, and contact angle experiment so as to provide parameters of microcapsule's physical properties for making binary self‐healing materials. As a result, the resultant microcapsules are suitable for fabricating self‐healing materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of graphene nanosheets on the dielectric, mechanical, thermal properties, and rheological behaviors of poly(arylene ether nitriles)
Authors: Yang Xulin , Zhan Yingqing , Zhao Rui , Liu Xiaobo 
Published: October 2011

AbstractPoly(arylene ether nitriles) (PEN) containing various contents of graphene nanosheets (GNs) was prepared via solution‐casting method and investigated for their dielectric, mechanical, thermal, and rheological properties. For PEN/GNs nanocomposite with 5 wt % GNs, the dielectric constant was increased to 9.0 compared with that of neat PEN (3.1) and dielectric losses of all nanocomposites were in the range of 0.019–0.023 at 1 kHz. The tensile modulus and strength were increased about 6 and 14% with 0.5% GNs, respectively. The fracture surfaces of the all PEN/GNs nanocomposites revealed that GNs had good adhesion to PEN matrix. The thermal properties of the nanocomposites showed significant increase with increasing GN loading. For 5 wt % GNs‐reinforced PEN nanocomposite, the temperatures corresponding to a weight loss of 5 wt % (Td5%) and 30 wt % (Td30%) increased by about 20 and 13°C, respectively. Rheological properties of the PEN nanocomposites showed a sudden change with the GN fraction and the percolation threshold was about 1 wt % of GNs. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Dispersion of nanoparticles in poly(vinyl chloride) grains during In situ polymerization
Authors: Georgiadou Stella , Jin Lili , Thomas Noreen. L. , Gilbert Marianne. , Brooks Brian W. 
Published: October 2011

AbstractInorganic nanoparticles such as calcium carbonate, silica, or hydrotalcite were dispersed in vinyl chloride prior to suspension polymerization. That led to the production of poly(vinyl chloride) (PVC) composite grains with higher porosity and different internal morphology from those of commercial PVC. The PVC/composite grain sizes and their distribution were also influenced by the presence of nanofillers. The distribution of filler nanoparticles (either calcium carbonate or silica) was not uniform throughout the PVC grains. Regions of high and low filler concentration were observed. Regions of pure polymer were also observed. Reasons for that are suggested. Hydrotalcite did not remain in the PVC grains. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Wood flour/polylactide biocomposites toughened with polyhydroxyalkanoates
Authors: Qiang Tao , Yu Demei , Gao Honghong 
Published: October 2011

AbstractPolylactide (PLA)‐based wood–plastic composites (WPCs) were successfully manufactured by extrusion blending followed by injection molding. The effects of polyhydroxyanoates (PHAs) on the mechanical and thermal properties and the morphologies of the PLA‐based WPCs were investigated with mechanical testing, thermal analysis, and scanning electronic microscopy (SEM). The inclusion of PHAs in the PLA‐based WPCs produced an increase in the impact resistance and a decrease in the tensile strength. The brittle–ductile transition of the impact strength for the PLA‐based WPCs toughened with PHAs was confirmed when the wood flour content was between 15 and 35 wt %. SEM images showed that the fracture surfaces of the PLA‐based WPCs toughened with PHAs were rougher than that of their nontoughened counterparts. The ternary PLA‐based WPCs exhibited ductile fracture during mechanical testing. Differential scanning calorimetry (DSC) showed that addition of PHAs into the composites caused deviations of the cold crystallization temperature and melting temperature of PLA. Thermogravimetric analysis indicated that the PHAs reduced the thermal stability of the PLA‐based WPCs. PHAs can be a green toughening agent for PLA‐based WPCs. The specific properties evidenced by the biocomposites may hint at their potential application, for example, in the automotive industry and civil engineering. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Protective effect of cashew gum nanoparticles on natural larvicide from Moringa oleifera seeds
Authors: Paula Haroldo C. B. , Rodrigues Maria L. L. , Ribeiro Wesley L. C. , Stadler Andre S. , Paula Regina C. M. , Abreu Flavia O. M. S. 
Published: October 2011

AbstractNanoparticles (NPs) have been used as carriers and as protective coatings of labile substances with applications in pharmacy, medicine, and agriculture. This work focused on the development of an entrapment process for the protection of a natural larvicide extracted from Moringa oleifera (MO) seeds with cashew gum (CG) NPs as a wall material. CG–MO NPs were characterized with regard to their size, morphology, kinetic release, thermal properties, and Stegomya aegypti larvae mortality. The result showed that the CG–MO NPs presented average particle sizes ranging from 288 to 357 nm, with unimodal distribution. MO larvicide active principle loading varied from 2.6 to 4.4%, and the entrapment efficiencies were in the range 39.1–60.8%. In vitro release kinetics showed a Fickian diffusional behavior. The thermal stability of the CG–MO NPs was related to the MO content, where their decomposition temperatures decreased with increasing MO active principle loading. Bioassays with third instar larvae showed that the mortality rate was related to larvicide loading and reached values up to 98 ± 3% mortality. The CG–MO NPs showed effective extract entrapment, with satisfactory larvicide effects even after 55 days of sample preparation and were effective as an improved and controlled release larvicide system. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Systematic review of wireless phone use and brain cancer and other head tumors
Authors: Repacholi Michael H. , Lerchl Alexander , Röösli Martin , Sienkiewicz Zenon , Auvinen Anssi , Breckenkamp Jürgen , d'Inzeo Guglielmo , Elliott Paul , Frei Patrizia , Heinrich Sabine , Lagroye Isabelle , Lahkola Anna , McCormick David L. , Thomas Silke , Vecchia Paolo 
Published: October 2011

AbstractWe conducted a systematic review of scientific studies to evaluate whether the use of wireless phones is linked to an increased incidence of the brain cancer glioma or other tumors of the head (meningioma, acoustic neuroma, and parotid gland), originating in the areas of the head that most absorb radiofrequency (RF) energy from wireless phones. Epidemiology and in vivo studies were evaluated according to an agreed protocol; quality criteria were used to evaluate the studies for narrative synthesis but not for meta‐analyses or pooling of results. The epidemiology study results were heterogeneous, with sparse data on long‐term use (≥10 years). Meta‐analyses of the epidemiology studies showed no statistically significant increase in risk (defined as P < 0.05) for adult brain cancer or other head tumors from wireless phone use. Analyses of the in vivo oncogenicity, tumor promotion, and genotoxicity studies also showed no statistically significant relationship between exposure to RF fields and genotoxic damage to brain cells, or the incidence of brain cancers or other tumors of the head. Assessment of the review results using the Hill criteria did not support a causal relationship between wireless phone use and the incidence of adult cancers in the areas of the head that most absorb RF energy from the use of wireless phones. There are insufficient data to make any determinations about longer‐term use (≥10 years). Bioelectromagnetics 33:187–206, 2012. © 2011 Wiley Periodicals, Inc.