Extrusão de compósitos de PP com fibras curtas de coco: efeito da temperatura e agentes de acoplamento

Santos, Evelise Fonseca dos; Moresco, Mauro; Rosa, Simone Maria Leal; Nachtigall, Sônia Marlí Bohrz

doi:10.1590/s0104-14282010005000036

Cited by 28 publications

(16 citation statements)

References 25 publications

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“…In other words, the tenacity thereof in relation to other composites, including composite PP+GFPP is higher, they are less rigid, as shown by the modulus of elasticity in Figure 1-b, and absorb more impact energy. Similar behavior was encountered by GOMES et al [14] comparing banana fiber with glass fiber in high density polyethylene matrix; and, SANTOS et al [12] compared curauá fiber with glass fiber in Polyamide-6 matrix. The lower modulus of elasticity was obtained by natural fiber composites without additives PP+BS and PP+CC, being the lowest result obtained by the composite PP+BS attributed to poor adhesion of the babassu fibers to the polypropylene matrix, as can be observed in Figure 3-1b, from which the fiber could be easily removed.…”

Section: Resultssupporting

confidence: 72%

Biocomposites reinforced with natural fibers:thermal, morphological and mechanical characterization

Lemos¹,

Pires

Albuquerque³

et al. 2017

Matéria (Rio J.)

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This study evaluates the thermal, morphological and mechanical behavior of polypropylene (PP) composite with different natural fibers. The fibers used were wood, sugarcane, bamboo, babassu, coconut and kenaf with and without coupling agent. The thermal, morphological and mechanical properties were evaluated, and a composite PP+GFPP (glass fiber) was used as reference. The interaction at the interface fiber-polymer matrix was studied by scanning electron microscopy (SEM) at the fractured surface of the composites, as expected the presence of maleic anhydride (MA) as coupling agent increasedthe interaction at the interface. The influence of natural fiber in the degree of crystallinity of the composites was evaluated by DSC analysis. The samples of PP+GFPP and PP+(PP-MA)+WF (wood flour) showed better temperature stability. PP+GF also presented superior flexural modulus. The thermal dynamic mechanical behavior was evaluated by DMA, a decrease in storage modulus with increasing temperature was observed, the PP+GF and the composite containing maleic anhydride and sugarcane fiber showed higher modulus. The natural fiber biocomposites studied, consistently presented lower flexural modulus and tensile strength than the reference composite, with and without the use of coupling agent. As expected the use of natural fibers lowered the density compared to the reference material.

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Section: Resultssupporting

confidence: 72%

Biocomposites reinforced with natural fibers:thermal, morphological and mechanical characterization

Lemos¹,

Pires

Albuquerque³

et al. 2017

Matéria (Rio J.)

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“…The hydrophilic character makes them incompatible with hydrophobic polymers, like polyolefins, restricting the mechanical charge transfer between the polymeric matrix and the fibers. To overcome this drawback, some strategies to promote larger polymer-fiber contact can be applied, like fiber surface treatment, polymer modification or introduction of coupling agents [10,11] . For polyolefins, polymers grafted with maleic anhydride are commonly used as coupling agent [12] .…”

Section: Introductionmentioning

confidence: 99%

Mechanical properties, morphology and thermal degradation of a biocomposite of polypropylene and curaua fibers: coupling agent effect.

et al. 2013

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Biocomposites of polymers with vegetal fibers have a broad spectrum of applications due to their high specific properties in comparison to their counterparts made with fiberglass. Polypropylene, PP, composites with curaua fiber compatibilized with different concentrations of maleic anhydride grafted polypropylene, PP-g-MA, were characterized according to their mechanical properties, morphologies and thermal stabilities in oxidative and inert atmospheres. The composites were prepared by single screw extrusion and injection molded specimens were used for testing. The composite with 20 wt % of curaua fiber with and without compatibilizer presented improved mechanical properties compared to pure PP. The use of PP-g-MA as a compatibilizer significantly increased fiber/matrix adhesion, however, the mechanical properties were only slightly improved in comparison with composites without compatibilizer. We observed an improvement in thermal stability of the composites, compared to that expected from the weighted average of the individual components, both under inert and oxidative atmospheres. Furthermore, the thermal stability improved under inert atmosphere as a function of the concentration of compatibilizer. In this situation, indeed, there was a different shift of the weight loss processes owing to the presence of the compatibilizer.

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“…Nesse caso, faz-se uso de um terceiro componente no compósito, diminuindo a tensão interfacial e aumentando a adesão entre as fases da blenda polimérica: o agente compatibilizante. Há vários compostos que apresentam essa função, tais como copolímeros [19] , metacrilato de glicidila [20] , anidrido maleico, [21] entre outros [19][20][21] . No que tange aos métodos de compatibilização de blendas poliméricas, os mesmos podem ser classificados como mecânicos, físicos e químicos.…”

Section: -Desenvolvimento E Caracterização De Compósitos Poliméricos unclassified

Desenvolvimento e Caracterização de Compósitos Poliméricos à Base de Poli(Ácido Lático) e Fibras Naturais

Lemos¹,

Martins²

2014

Polímeros

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Resumo: O presente trabalho busca avaliar o comportamento de compósitos que contêm em sua formulação um biopolímero originário de indústrias da agricultura sustentável. O biopolímero selecionado, poli(ácido lático), (PLA) e um polímero termoplástico (poliuretano), (TPU), foram misturados a fibras naturais (madeira e coco). Em um primeiro momento, foram preparadas formulações contendo 10, 20 e 30% em massa de fibra vegetal em relação à blenda de PLA-TPU (na proporção de 70/30% em massa). Em um segundo momento, manteve-se a mesma proporção em massa de fibra vegetal em relação à blenda de PLA-TPU, porém foram adicionados 5% em massa de anidrido maleico. Na sequência, as formulações foram avaliadas através de caracterizações físico-mecânicas, térmicas e microscópica. De um modo geral, as análises mostraram evidências bastante conclusivas sobre a baixa adesão interfacial entre a blenda polimérica e as fibras vegetais. Deve-se salientar a fraca atuação do anidrido maleico como agente de acoplamento, haja vista que as formulações que o continham não apresentaram melhoras em suas propriedades. Portanto, os resultados indicam que os biocompósitos formulados possam atender à necessidade de nichos específicos de mercados populares, como o de decoração, os quais não demandam alto desempenho de seus produtos, viabilizando o uso de fibras vegetais devido à redução de custo do compósito final. Palavras-chave: Biopolímero, poli(ácido lático), compósitos poliméricos, fibras vegetais. Development and Characterization of Polymeric Composites Based on Poly (Lactic Acid) and Natural FibersAbstract: This work evaluates the behavior of composites containing a biopolymer derived from sustainable agriculture industries. The biopolymer selected, poly(lactic acid) -PLA -, in combination with a thermoplastic polymer (polyurethane) -TPU -was mixed with natural fibers, wood and coconut. In a first step, formulations containing 10, 20 and 30% by weight of fiber in relation to the blend of PLA-TPU (in the ratio 70/30 wt%) were prepared. In the second step, the same set of formulations was maintained but with addition of 5 wt% of the coupling agent maleic anhydride. These composites were characterized by means of physical-mechanical, thermal and microscopic techniques. The results indicated a low interfacial bonding between the polymeric blend and the vegetal fibers. It is important to emphasize the poor performance of the coupling agent, because the formulations containing maleic anhydride did not show any improvement in their properties in comparison to the standard material. Therefore, the biocomposites studied in this paper can be used when high-performance materials are not required, as in home decoration articles, making it feasible to use vegetal fibers in order to reduce the cost of the final composite. Keywords: Biopolymer, poly(lactic acid), polymeric composites, vegetal fibers. IntroduçãoMuito tem sido discutido sobre as principais políticas de gestão de resíduos de materiais utilizados na indústria em geral, porém, a maior reflexão ...

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Extrusão de compósitos de PP com fibras curtas de coco: efeito da temperatura e agentes de acoplamento

Cited by 28 publications

References 25 publications

Biocomposites reinforced with natural fibers:thermal, morphological and mechanical characterization

Biocomposites reinforced with natural fibers:thermal, morphological and mechanical characterization

Mechanical properties, morphology and thermal degradation of a biocomposite of polypropylene and curaua fibers: coupling agent effect.

Desenvolvimento e Caracterização de Compósitos Poliméricos à Base de Poli(Ácido Lático) e Fibras Naturais

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