Aspectos históricos da vulcanização

Costa, Helson M. da; Visconte, Leila L. Y.; Nunes, Regina C. R.; Furtado, Cristina R. G.

doi:10.1590/s0104-14282003000200011

Cited by 27 publications

(23 citation statements)

References 19 publications

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“…Através da vulcanização consegue-se transformar as propriedades plás-ticas da borracha, eliminar sua sensibilidade ao calor e obter um corpo elástico capaz de retomar suas dimensões primitivas depois de uma deformação, mesmo em condições extremas de temperatura [8][9][10][11][12] .…”

Section: Materiaisunclassified

Caracterização mecânica e térmica da borracha natural formulada e vulcanizada dos clones: GT 1, IAN 873, PB 235 e RRIM 600

et al. 2009

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Resumo: Neste trabalho estudou-se o desempenho mecânico e térmico de compostos de borracha natural (Hevea brasiliensis) de 4 diferentes clones (GT 1, IAN 873, PB 235 e RRIM 600) cultivados no Estado de São Paulo, assim como de uma mistura destes clones e de uma borracha comercial, GEB-1. Estas borrachas foram formuladas e vulcanizadas com tempos de 5, 7 e 9 minutos. A caracterização foi realizada por calorimetria exploratória diferencial, termogravimetria, ensaios de resistência à tração, análise dinâmico-mecânica, medidas de dureza Shore A, microscopia eletrônica de varredura e espectroscopia na região do infravermelho. Os resultados permitiram concluir que o tempo de vulcanização e o tipo de clone não influenciaram na temperatura de transição vítrea (Tg) dos compostos. Os valores de Tg obtidos por DMA foram de cerca de -62 °C, e os resultados ensaios de dureza apresentaram valores próximos de 60 para todos os compostos estudados. Os ensaios de resistência à tração mostraram que o melhor desempenho mecânico foi obtido pelo clone RRIM 600. De acordo com os resultados obtidos neste trabalho, todos os clones atingiram as propriedades reportadas na literatura, podendo ser utilizados, em princípio, nas indústrias de artefatos de borracha separadamente ou na forma de mistura. Palavras-chave: Borracha natural, caracterização, compostos, clones.Mechanical and Thermal Characterization of Compounds of Natural Rubber of the Clones: GT 1, IAN 873, PB 235 and RRIM 600 Abstract: The objective of this work was to study the mechanical and thermal performance of natural rubber (Hevea brasiliensis) compounds of different types of clones (GT 1, IAN 873, PB 235 and RRIM 600), as well as a mixture made from these clones and a commercial rubber GEB-1. These rubbers were formulated and prepared in a two-roll mill and vulcanized at different times (5, 7 and 9 minutes). The evaluation of the mechanical and thermal performance of different natural rubber compounds was carried out by differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), mechanical properties (tensile and hardness tests), dynamic mechanic thermal analysis (DMTA), scanning electron microscopy (SEM), and infrared spectroscopy (FTIR). The values obtained for glass transition temperature (Tg) for vulcanized rubbers were found to be around -62 °C, while in the hardness test the values obtained were close to 60, with no great variations when the vulcanization time and type of clone were varied. The tensile tests showed that the best performance was obtained for the clone RRIM 600. All the samples studied were in agreement with standard specifications required for application in the rubber industry, indicating that all clones can be used, in principle, in the rubber industry in blended or unblended forms.Keywords: Natural rubber, clone, compound, characterization. IntroduçãoA pesquisa para a seleção e avaliação dos clones, do lá-tex e da borracha natural é importante para garantir o sucesso da cultura de seringueira. No Brasil, as regiões Sudeste e Centro-Oes...

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Section: Materiaisunclassified

Caracterização mecânica e térmica da borracha natural formulada e vulcanizada dos clones: GT 1, IAN 873, PB 235 e RRIM 600

et al. 2009

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“…It is a natural, biocompatible and flexible polymer obtained mainly from the Hevea brasiliensis tree. In general, rubbers are benefited by vulcanization processes which consist of the crosslink of the polymer chains improving mainly the mechanical properties of the compound [8,9] . Currently, the rubber has been of great interest of study as result of the possibility of composites preparation as a new approach to technology development [10,11] which may contain organic compounds such Defatted Soy Flour [12] , or carbon black [13,14] as both reinforce and conductive agents.…”

Section: Introductionmentioning

confidence: 99%

“…However, this cost could be reduced using silica obtained from organic waste. A Similar study recently reported in the literature describes methods for obtaining silica from rice hull ash (residue production) [15][16][17] , oilshare residue [18] , and the use of organoclay as a substituent of silica (fillers) in rubber composites [19] .…”

Section: Introductionmentioning

confidence: 99%

Sugarcane bagasse ash: new filler to natural rubber composite

et al. 2014

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Waste recycling has been the subject of numerous scientific researches regarding the environmental care. This paper reports the redirecting of sugarcane bagasse ash (SBA) as new filler to natural rubber (NR/SBA). The NR/ SBA composites were prepared using an opened cylinder mixer to incorporate the vulcanization agents and different proportions of residue (SBA). The ash contains about 70-90% of inorganic compounds, with silica (SiO 2 ) being the main compound. The SBA incorporation improved the mechanical properties of the vulcanized rubber. Based on these results, a new use is proposed for the agro-industry organic waste to be implemented in the rubber vulcanization process, aimed at improving the rubber physical properties as well as decreasing the prices of natural rubber composites.

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“…Due to various type of fiber, it can be seen that the tensile strength is affected by filler type, filler size, filler shape and their surface area [7]. It would also be controlled by the nature of the filler and matrix [8]. By comparing four natural fibers in this study, we may proved that pineapple fiber showed the highest tensile strength among others, although with low filler loading (5%) compared to other.…”

Section: Tensile Strengthmentioning

confidence: 69%

Comparing Various Type of Natural Fibers as Filler in TPU: Mechanical Properties, Morphological and Oil Absorption Behavior

et al. 2017

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Abstract. The idea of using natural fibers as filler in various polymers has been extensively studied. Various types of natural fibers and polymers have been identified and it can be varied according to the particular application and the two main composite materials will have advantages and disadvantages of each. However, natural fibers are usually selected as filler because it is readily available and environmentally friendly, inexpensive, non-toxic, biodegradable and still have good characteristics for a variety of uses. In this study, four types of natural fiber have been used which; coconut shell, coconut fiber, corn cob, and pineapple skin, as fillers in thermoplastic polyurethane (TPU). The mixing process conducted through melt mixing techniques. The percentage of TPU and natural fibers are 100/0, 95/5, 90/10 and 85/15. Different type of fiber will affect the mechanical properties of the composites and have been studied through tensile testing. It showed that the result for pineapple fiber at 5% was the highest and can also be related to the characterizations of this composite that have been studied via the SEM morphology. Swelling testing is also having been done to prove the absorbency ability by natural fiber composites in cooking oil and engine oil. Then it concluded that the pineapple fiber absorbed large amount of both oil compared to others.

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Aspectos históricos da vulcanização

Cited by 27 publications

References 19 publications

Caracterização mecânica e térmica da borracha natural formulada e vulcanizada dos clones: GT 1, IAN 873, PB 235 e RRIM 600

Caracterização mecânica e térmica da borracha natural formulada e vulcanizada dos clones: GT 1, IAN 873, PB 235 e RRIM 600

Sugarcane bagasse ash: new filler to natural rubber composite

Comparing Various Type of Natural Fibers as Filler in TPU: Mechanical Properties, Morphological and Oil Absorption Behavior

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