Empregados na Indústria

Júnior, Carlos Alberto Rios Brito; Fleming, Robson; Pardini, Luiz Carlos; Alves, Nilton Pereira

doi:10.4322/polimeros.2013.006

Cited by 9 publications

(5 citation statements)

References 18 publications

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“…Polyacrylonitrile fibers or PAN fibers as they are commonly known, are the result of the acrylonitrile polymerization process in the presence of a catalyst peroxide [41,42]. Its use is linked to composite structures for military and commercial aircraft [43].…”

Section: Polyacrylonitrile (Pan)mentioning

confidence: 99%

Mechanical performance of fibers in hot mix asphalt: A review

Slebi-Acevedo

Lastra-González

Pascual-Muñoz

2019

Construction and Building Materials

166

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The use of fibers in hot mix asphalt (HMA) has become a much more attractive alternative for the construction of road pavements. Numerous studies have shown that the incorporation of fibers in the mixture improves fatigue resistance, permanent deformation and stiffness. The aim of this paper is to present a review of the mechanical impact of fibers in HMA by analyzing their reinforcement effect in a qualitative and quantitative manner. Fiber properties and characterization tests on fiber-modified bitumen are discussed. Quantities, blending procedures and performance of bituminous mixtures with different types of fibers are presented. Results of mechanical improvement are displayed. Based on the current research results, depending on the properties and the type of mixture in which they are used, each type of fiber seems to improve certain parameters more than others. Coconut fibers and waste fibers are described as environmentally friendly alternatives.

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Section: Polyacrylonitrile (Pan)mentioning

confidence: 99%

Mechanical performance of fibers in hot mix asphalt: A review

Slebi-Acevedo

Lastra-González

Pascual-Muñoz

2019

Construction and Building Materials

166

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“…Thus, the PAN polymer melt before crosslinking and suppresses the exothermic reactions related to the cyclization reactions which takes place over 200 °C. In that way, PAN fibers can be spun by using conventional extrusion process (melt spinning) [4,12] . In relation to acrylic fiber production this approach can lead to a substantial cost reduction in relation to the traditional wet and dry spinning processes [1] .…”

Section: Introductionmentioning

confidence: 99%

“…In this way, some processes were patented, mainly from BASF and Dupont, but they were not commercially viable because the need for water at high temperature (200 °C) as a melt carrier [5][6][7] . Besides, the extrusion process has to be accomplished at high pressure (3)(4)(5)(6)(7), and, as a consequence, robust equipment was needed for continuous extrusion.…”

Section: Introductionmentioning

confidence: 99%

“…The solution is then pumped through a spinneret having a multiplicity of tiny holes [1,2] . The solution used in a wet spinning process usually consists of 10 to 30% by weight of PAN dissolved in a polar solvent, such as dimethylformamide (DMF), dimethysulfoxide (DMSO) or dimethylacetamide (DMAc) [3,4] . Although PAN fibers can be produced by either wet or dry spinning processes, wet spinning is used to produce nearly all commercial aerospace grade PAN-based carbon fibers.…”

Section: Introductionmentioning

confidence: 99%

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Thermal Stabilization study of polyacrylonitrile fiber obtained by extrusion

et al. 2015

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SbstractA low cost and environmental friendly extrusion process of the Polyacrylonitrile (PAN) polymer was viabilized by using the 1,2,3-propanetriol (glycerol) as a plasticizer. The characterization of the fibers obtained by this process was the object of study in the present work. The PAN fibers were heat treated in the range of 200 °C to 300 °C, which is the temperature range related to the stabilization/oxidation step. This is a limiting phase during the carbon fiber processing. The characterization of the fibers was made using infrared spectroscopy, thermal analysis and microscopy. TGA revealed that the degradation of the extruded PAN co-VA fibers between 250 °C and 350 °C, corresponded to a 9% weight loss to samples analyzed under oxidizing atmosphere and 18% when the samples were analyzed under inert atmosphere. DSC showed that the exothermic reactions on the extruded PAN co-VA fibers under oxidizing synthetic air was broader and the cyclization started at a lower temperature compared under inert atmosphere. Furthermore, FT-IR analysis correlated with thermal anlysis showed that the stabilization/oxidation process of the extruded PAN fiber were coherent with other works that used PAN fibers obtained by other spinning processes.

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“…nitrile, carbonyl), one may promote the dissolution of metal salts; however, the strong van der Waals interactions between these groups drastically increase the CED of the neat polymer and the T g values. In a typical example, high-molecular-weight poly(acrylonitrile) (PAN) shows a high glass transition at 125 • C (table 2) and CED (620−900 J cm −3 mol −1 ), which could barely solvate common lithium salts in the absence of small molecular solvents [92,93]. Therefore, with commercially available polymers, it is rather difficult to obtain highly conductive and self-standing SPEs membranes.…”

Section: Developing Advanced Polymer Matricesmentioning

confidence: 99%

Ion transport and structural design of lithium-ion conductive solid polymer electrolytes: a perspective

Tong

Song²,

Wu³

et al. 2022

Mater. Futures

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Solid polymer electrolytes (SPEs) possess several merits including no leakage, ease in process, and suppressing lithium dendrites growth, etc. These features are beneficial for improving the cycle life and safety performance of lithium metal batteries (LMBs), as compared to conventional non-aqueous liquid electrolytes. Particularly, the superior elasticity of polymeric material enables the employment of SPEs in building ultra-thin and flexible batteries, which could further expand the application scenarios of high-energy LMBs. In this perspective, recent progresses on ion transport mechanism of SPEs and structural designs of electrolyte components (e.g., conductive lithium salts, polymer matrices) are scrutinized. In addition, key achievements in the field of single lithium-ion conductive SPEs (SLIC-SPEs) are also outlined, aiming to provide the status quo in those SPEs with high selectivity in cationic transport. Finally, possible strategies for improving the performance of SPEs and their LMBs are also discussed.

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Empregados na Indústria

Cited by 9 publications

References 18 publications

Mechanical performance of fibers in hot mix asphalt: A review

Mechanical performance of fibers in hot mix asphalt: A review

Thermal Stabilization study of polyacrylonitrile fiber obtained by extrusion

Ion transport and structural design of lithium-ion conductive solid polymer electrolytes: a perspective

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