1,721,028 research outputs found
Organoclay modification by insertion of hyperbranched aromatic polyamides
No full textHyperbranched (HB) aromatic polyamides (aramids) synthesized from A2 (p-phenylenediamine) + B3 (trimesic acid) reactants have been intercalated into three organically-modified montmorillonite-type clays (OMMT), namely Cloisite 30B®, Dellite 43B® and Dellite 72T®. Solution intercalation has been applied for the preparation of the OMMT/HB aramid pair. The presence of HB aramid has been found to increase the interlayer distances of some silicate layers and to reduce those of others. This phenomenon has been explained by the broad polydispersity of the HB aramid leading to a complex mixture of macromolecules which can interact with the organic compatibilizer of the clay in different ways and thus affect the arrangement of it inside the galleries. Purthermore, the swelling of the layered silicate in the solvent used has been found to be a key parameter, which strongly biases polymer intercalation. TGA measurements have evidenced the active role of clay in the degradation process of HB aramid and the higher thermal stability of clay/HB aramid systems, as compared to the pristine organoclays. Finally, the Cloisite 30B®/HB aramid system has been used as masterbatch to produce polyamide 6 (PA6)-based nanocomposites. WAXD and TEM characterization have evidenced the possibility to obtain fully exfoliated nanocomposites
NMR Studies on a Hyperbranched Aromatic Polyamide from A2 and B3 Monomers: Structure and Interactions with Lithium Salts
No full textThe 1H and 13C NMR Spectra of a Hyperbranched Aromatic Polyamide from p-Phenylenediamine and Trimesic acid
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Ethoxysilyl-modified hyperbranched polyesters as multifunctional coupling agents for epoxy-silica hybrid coatings
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Antistatic epoxy coatings with carbon nanotubes obtained by cationic photopolymerization
No full textSynthesis of Alkyl-functionalized Hyperbranched Polymers and their use as additives in Cationic Photopolymerization of Epoxy Resins
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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