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981.
Gouveia Paula F. Mesquita-Guimarães Joana Galarraga-Vinueza Maria E. Souza Júlio C. M. Moreira Anderson C. Silva Filipe S. Fredel Márcio C. Henriques Bruno 《Journal of Materials Science》2021,56(20):11682-11697
Journal of Materials Science - The objective of this study was to develop a replica method for producing zirconia-reinforced bioactive glass (ZRBG) porous structures for bone... 相似文献
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Maria Laura Di Lorenzo 《应用聚合物科学杂志》2010,116(3):1408-1413
The isothermal and nonisothermal crystallization kinetics of cis‐1,4‐polybutadiene has been investigated with respect to the content of cis units and the linearity of the main chain. The rate of spherulite growth increases with chain regularity as the presence of branches as well as segments with different configurations slows the crystallization rate. The major parameter that determines the crystallization rate is the presence in the formulation of heterogeneities that favor the formation of primary nuclei and determine an anticipated onset of crystallization. As the activity of the heterogeneous nuclei depends more on the type and number of foreign particle than on any chain parameter, no straightforward information on the influence of the chain structure on the crystallization rate can be derived by mere calorimetric analysis, at least for analyzed samples. It is only with combined analysis by optical microscopy that comprehensive information on the crystallization kinetics of cis‐1,4‐polybutadiene can be derived. The results reported in this contribution point out the importance, in polymer science, of preferring complementary instrumentation and not limiting experimental investigations to a single technique of analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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Fabio Maria Sabbatini Dr. Romano Di Fabio Dr. Mauro Corsi Dr. Paolo Cavanni Dr. Steve M. Bromidge Dr. Yves St‐Denis Dr. Lucilla D'Adamo Dr. Marilisa Rinaldi Dr. Chiara Savoia Dr. Claudia Mundi Dr. Benedetta Perini Dr. Andrew J. Carpenter Dr. Giovanna Dal Forno Dr. Federico Faggioni Dr. Michela Tessari Dr. Francesca Pavone Dr. Alberto Buson Dr. Mario Mattioli Dr. Elisabetta Perdona' Dr. Sergio Melotto Dr. 《ChemMedChem》2010,5(9):1450-1455
988.
Marcelo A. V. Souza Luiz Claudio de Santa Maria Marcos A. S. Costa Wang S. Hui Luciana C. Costa Hiram C. Araujo Filho Sandro C. Amico 《Polymer Bulletin》2011,67(2):237-249
Phosphinic-derivative poly(styrene-co-divinylbenzene)-based on PS–DVB copolymers with different porosity degrees have been prepared by aromatic electrophilic substitution reaction using PCl3/AlCl3 followed by base-promoted hydrolysis. The phosphorylation reaction was analyzed by infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry (TG/DTG). In addition, the phosphorous content of the phosphorylated copolymers was determined by spectrophotometry using the method based on sodium molybdate reactant so that the extension of that modification could be assessed. The performance of the phosphorylated resins in the extraction of Pb2+ from aqueous solutions in a batch system was also evaluated. The Pb2+ content was determined by atomic absorption spectrometry (AAS). These materials presented excellent extraction capacity under the contact time of 30 min and pH 6. 相似文献
989.
Moacir Fernandes Ferreira Júnior Elaine Angélica Ribeiro Mundim Guimes Rodrigues Filho Carla da Silva Meireles Daniel Alves Cerqueira Rosana Maria Nascimento de Assunção Marcos Marcolin Mara Zeni 《Polymer Bulletin》2011,66(3):377-389
Cellulose, obtained both from sugarcane bagasse and mango seeds, was used for synthesizing cellulose acetate in order to produce asymmetric membranes. These were compared to membranes of commercial cellulose acetate (Rhodia). All produced membranes were asymmetric, characterized by the presence of a dense skin and a porous support. Differences regarding the morphology of the surfaces as well as of the porous support can be noticed. Scanning Electron Microscopy (SEM) showed that the morphology of the superficial layer, responsible for transport, depends on the different lignin content of the starting material and also on the viscosity average molecular weight of the cellulose acetates produced from sugarcane bagasse, mango seed, and Rhodia’s commercial cellulose acetate. 相似文献
990.
The mechanical properties of artists’ acrylic (latex) paint films containing different volume fractions of TiO2, CaCO3 and kaolin were measured in uni-axial tension over a broad range of temperatures and crosshead speeds. Young’s modulus results in the glassy region were first compared with several micromechanics theories for particle-filled composites containing elastic phases. It was found that the Mori-Tanaka theory slightly under-predicted the modulus enhancement, while the Lielens approach provided the most accurate results. A nonlinear viscoelastic material model involving a Prony series and the neo-Hookean hyperelastic function was used to represent the tensile data up to relatively small strains of a few percent. From the experimental data, the material model was calibrated and the required parameters were determined. The derived parameters were then used to re-construct relaxation modulus plots, which were compared with the approximations given by Clements and Mas for the viscoelastic Mori-Tanaka theory in the time-domain. It was found that the experimentally observed modulus enhancement was much stronger than the predicted values in the rubbery region. Mechanisms such as constrained polymer at the inorganic particle interface, and the possible formation of a percolation network are discussed. 相似文献