Controlled Polymerization
Mostrando 1-12 de 71 artigos, teses e dissertações.
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1. EFEITO DO PH, ESPÉCIE E CONCENTRAÇÃO IÔNICA NA ABSORÇÃO DE ÁGUA DE HIDROGÉIS BIONANOCOMPÓSITOS CONSTITUÍDOS DE CMC/PAAM/LAPONITA RDS
The objective of this paper was to study the effect of pH, concentration and ionic species on the water absorption of the bionanocomposite hydrogels based on carboxymethylcellulose polysaccharide and laponite nanoclay. Bionanocomposite hydrogels were obtained via free radical polymerization. It was possible to observe that the swelling degree (Q) and kinetic
Quím. Nova. Publicado em: 21/10/2019
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2. Numerical Simulation of Atom-Transfer Radical Polymerization of tert-butyl Methacrylate
Block copolymers based on tert-butyl methacrylate (tBMA) have many uses, such as thermo‐responsive polymers, amphiphilic copolymers, and many applications in the medical field. Atom-transfer radical polymerization (ATRP) is the main technique to produce these controlled macromolecular architectures. This paper provides a simplified kinetic modeling and com
Mat. Res.. Publicado em: 02/09/2019
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3. Evaluación del uso de acetileno como fuente de carbono en la carburización de aceros
ABSTRACT The effect of using acetylene as a carbon source in the gas carburization of AISI/SAE 8620 steel was evaluated in this work. For this purpose, a gaseous carburizing system was designed and manufactured with the following characteristics: controlled production of a carburant gaseous atmosphere, inert and hermetic isothermal reaction zone and carbon/o
Matéria (Rio J.). Publicado em: 19/07/2018
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4. Estudo do efeito dos parâmetros de síntese na condutividade elétrica do compósito fluoreto de polivinilideno / polianilina
ABSTRACT The electroactive polymers have been the subject of many studies in the last decade, mainly because its unique properties. They are used in composite structures, which allow its application in many fields, as for example, sensors and artificial muscles. The electrical properties of these composites are influenced by the doping state of the electroac
Matéria (Rio J.). Publicado em: 10/08/2017
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5. Atom Transfer Radical Polymerization of Methyl Methacrylate Mediated by Grubbs 1st and 2nd Generation Catalysts: Insight into the Active Species
Ruthenium benzylidene complexes were evaluated as catalysts in atom-transfer radical polymerization (ATRP) of methyl methacrylate (MMA) under different reaction conditions. The mechanism by which Grubbs 1st and 2nd generation catalysts mediate olefin metathesis has been studied, little is known regarding the mechanism of ATRP reaction promoted by these compl
J. Braz. Chem. Soc.. Publicado em: 2017-08
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6. AN ALTERNATIVE ROUTE TO PRODUCE STANDARDS FOR GEL PERMEATION CHROMATOGRAPHY USING NITROXIDE MEDIATED POLYMERIZATION
Abstract All over the world standards for Gel Permeation Chromatography (GPC) are produced using ionic polymerization. Standards are commercialized in a broad range of molecular weight and their dispersity (Ð) must be lower than 1.1. This work proposes the synthesis of polystyrene standards using Nitroxide Mediated Polymerization (NMP), an alternative techn
Braz. J. Chem. Eng.. Publicado em: 2017-01
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7. Synthesis and applications of polystyrene-block-poly(N-vinyl-2-pyrrolidone) copolymers
Abstract This work describes the synthesis and applications of amphiphilic polystyrene-block-poly(N-vinyl-2-pyrrolidone) (PS-b-PVP) copolymers as a silver and silica nanoparticle surface modification agent. The synthesis of PS-b-PVP was carried out using controlled/living radical polymerization techniques. The synthesis of the block copolymers was confirmed
Polímeros. Publicado em: 15/03/2016
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8. Mechanical and thermal behavior of polyvinyl alcohol reinforced with aligned carbon nanotubes
ABSTRACTIn recent years, due to their high specific mechanical properties, the polymer matrix composites have been widely used. In particular, carbon nanotubes (CNTs) have been used as reinforcement due to its exceptional mechanical and electrical properties. In this work the mechanical behavior of polyvinyl alcohol (PVA) reinforced with different percentage
Matéria (Rio J.). Publicado em: 2015-09
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9. Preparation and characterization of hydrogels with potential for use as biomaterials
Hydrogels have been extensively explored for biomedical applications due to their ability to absorb high water content in its structure, which gives excellent biocompatibility. This work aims at obtaining biocompatible hydrogels with potential for use in increasing the mechanical strength of bone substitutes, or controlled drug release. Poly (N-vinyl-2-pyrro
Mat. Res.. Publicado em: 2014-08
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10. Effect of tamoxifen in RAFT miniemulsion polymerization during the synthesis of polymer nanoparticles
Tamoxifen (TXF) is currently the only hormonal agent used for treatment of breast cancer. Although very effective, TXF presents low solubility in water, which affects its absorption and bioavailability. A common strategy to overcome this barrier is the formulation of a drug delivery system (DDS) in order to increase the drug stability and improve the treatme
Polímeros. Publicado em: 27/05/2014
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11. Preparation of poly(urethane-urea) nanoparticles containing açaí oil by miniemulsion polymerization
Polyurethane nanoparticles (NPs) are promising candidates for the controlled and targeted delivery of therapeutics in a variety of biomedical applications. In this work, a report is made of NPs produced by miniemulsion polymerization with isophorone diisocyanate (IPDI) and castor oil, glycerol, and poly(ethylene glycol) (PEG) with molar masses 400 and 1000 a
Polímeros. Publicado em: 27/08/2013
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12. Prospecção e síntese de poli(ácido láctico) para desenvolvimento de suportes na engenharia tecidual / Prospection and synthesis of poly (lactic acid) for scaffold development in tissue engineering
The advances in modern medicine, dentistry and engineering, combined with the increase of life expectancy, have allowed the development of techniques for biomanufacturing and biomaterials that create a better life quality. These techniques should enable the mimicking of living structures, both in form and function, making it possible to replace defective or
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/10/2011