Polyolefins
Mostrando 1-12 de 19 artigos, teses e dissertações.
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1. Stabilization effect of kraft lignin into PBAT:Thermal analyses approach
ABSTRACT Sterically hindered phenols are an important class of synthetic antioxidants for polymers, commonly incorporated to inhibit polyolefins or polyesters oxidation. However, synthetic antioxidants use is under restricted regulation due to their potential health risk and environmental impacts. Thus, great interest has been attracted to the phenol-based n
Matéria (Rio J.). Publicado em: 16/09/2019
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2. High shear dispersion of tracers in polyolefins for improving their detection
Abstract An efficient recycling of end-of-life products is of crucial interest from an economical and ecological point of view. However, the near infrared spectroscopy often used for the optic sorting processes is limited because of the absorption of carbon black present in black plastics and as it only sorts as a function of chemical formulas. The tracing t
Polímeros. Publicado em: 2015-10
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3. Efeitos da descarga corona em superfície de polipropileno em temperatura ambiente e acima / Effects of corona discharge on polypropylene surface at room temperature and above
Este trabalho avalia o efeito do tratamento por descarga corona em temperatura ambiente e acima para promover aumento da energia de superfície em filmes de polipropileno (PP). Submeteram-se amostras de polipropileno ao tratamento corona em sistema com geometria ponta-plano e utilizou-se de tensão de polarização dos eletrodos em 5kV . Avaliaram-se os efei
Publicado em: 2011
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4. Estudo, caracterização e aplicação de nanocompósitos utilizando poliolefinas funcionalizadas / Stydy, characterization and application of nanocomposites using functionalized polyolefins
É apresentada a preparação e a caracterização de nanocompósitos, produzidos a partir da vermiculita e poliolefinas funcionalizadas como matriz polimérica. As poliolefinas foram representadas pelo polietileno de baixa densidade (PEBD) e o polietileno de baixa densidade linear (PEBDL), utilizadas com e sem o anidrido maleico. A vermiculita de origem nac
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/07/2010
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5. Evaluación de la degradación por termoxidación de termoplásticos empleados en aplicaciones agrícolas
Polyolefins as polypropylene are used in agricultural applications for plant assistance and protection. However, their massive consumption is causing environmental problems. In this study, polypropylene and polypropylene blends with starch and biodegradable polymers such as Mater-Bi that could be used in this agricultural endeavor, were exposed to several th
Rem: Revista Escola de Minas. Publicado em: 2009-12
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6. Thermoplastic polyolefins as formaldehyde free binders in highly filled lignocellulosic panel boards: using glycerine as a processing aid in kenaf fiber polypropylene boards
A new technique was developed to make highly loaded (up to 95%) formaldehyde free natural fiber boards. The purpose of the paper is to report a broad study on 85% kenaf boards using linear thermoplastic polymers as the binder in preparing the boards to determine if these materials have potential in commercial applications by comparing them to other commercia
Materials Research. Publicado em: 2008-12
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7. Fotodegradação de polímeros solúveis em água e moléculas modelo via processos oxidativos avançados / Photodegradation of water soluble polymers and model molecules via advanced oxidative processes
The aim of this work was to investigate polymer photodegradation mechanisms and stabilizing agents. The course of photooxidative degradation of some water soluble polymers (poly(vinylpyrrolidone), PVP; poly(acrylamide), PAM and poly(ethylene glycol), PEG) in the presence of hydrogen peroxide, Fenton reagent and iron salt has been investigated. PVP showed the
Publicado em: 2008
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8. Selection criteria for recycled polyolefins from urban wastes by using TG analysis
The thermal behavior of a mixture of recycled polyolefins (PE/PP mix), variously colored recycled polyolefins, recycled polyolefin blends and recycled polyolefin/PET blends was analyzed by thermogravimetry. Atmospheres of nitrogen and synthetic air were used to compare the effects of inert and oxidative medium. Four characteristic temperatures, T1, T2, T3 an
Materials Research. Publicado em: 2007-12
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9. Modeling and simulation of liquid phase propylene polymerization in industrial loop reactors / Modelagem e simulação de reatores industriais em fase liquida do tipo Loop para polimerização de propileno
Tubular loop reactors are widely used in the polyolefins industries. In the particular case of polypropylene production, loop reactors are part of the Spheripol technology. Loop reactors are composed of two tubular reactors that are connected by a feed point and a pump that is responsible for promoting recirculation of the reaction mass. The dynamic simulato
Publicado em: 2007
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10. Avaliação da degradação de polietilenos contendo aditivo pró-degradante / Evaluation of the degradation of polyethylene containing prodegradant additive
Filmes de polietileno (PE) contendo aditivo pró-degradante à base de um composto de cobalto foram expostos a intemperismo natural por 12 meses, em Canoas, RS (30º S, 59º W), sob condições de umidade ambiente e saturação de umidade. Procurou-se desenvolver condições de ensaio adequado para a degradação abiótica e biótica, visando monitorar alter
Publicado em: 2007
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11. A comparative study of effect of compatibilization agent on untreated and ultrasonically treated waste ground rubber tire and polyolefin blends
The development of thermoplastic elastomer blends from waste tire powder and two polyolefins, Viz. maleic anhydride grafted polypropylene and LDPE, was studied. The polymer blends were processed using a twin-screw extruder equipped with a well-designed screw configuration. The blends studied contained a dispersed phase of waste rubber powder obtained from wa
Polímeros. Publicado em: 2006-12
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12. Modeling and simulation of an industrial autoclave reactor for the production of low-density polyethylene (PEBD) / Modelagem e simulação de um reator autoclave para a produção de polietileno de baixa densidade (PEBD)
High-pressure polymerization in autoclave reactors is one of the most currently technologies used for production of polyolefins, particularly polyethylene. Pressures until 3000 atm and temperatures covering the range from 150 to 300 DEGREES C are usually employed in this system. In the present work high-pressure ethylene polymerization process to produce low
Publicado em: 2005