Influence of notching and molding conditions on determination of EWF parameters in polyamide 6

Yamakawa, Roberto S.; Razzino, Carlos A.; Correa, Carlos A.; Hage, Elias

doi:10.1016/s0142-9418(03)00080-1

Cited by 29 publications

(19 citation statements)

References 19 publications

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“…Recently, the essential work of fracture concept (EWF) has gained acceptance for assessing the toughness of ductile polymers (Karger-Kocsis et al, 1998;Ching et al, 2000;Hashemi, 2000;Arkhireyeva and Hashemi, 2001, 2002a, b, 2004Karger-Kocsis and Bárány, 2002;Yamakawa et al, 2004). This method is widely used for the investigation of in-plane toughness of films, sheets using single-or double edge-notched tensile specimens (SEN-T Hashemi, 2001, 2002a) and DEN-T (Karger-Kocsis et al, 1998;Arkhireyeva and Hashemi, 2004), respectively).…”

Section: Introductionmentioning

confidence: 99%

In-plane and Out-of-plane Fracture Toughness of Physically Aged Polyesters as Assessed by the Essential Work of Fracture (EWF) Method

Bárány

Ronkay²,

Karger‐Kocsis³

et al. 2005

Int J Fract

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The in-plane (mode I) and out-of-plane (mode III) fracture behavior of amorphous (co)polyester sheets are studied as a function of physical aging using the essential work of fracture (EWF) concept. Physical aging was followed by measuring the yield stress and enthalpy relaxation of the (co)polyesters. The specific essential work of fracture term did not reflect the physical aging either in mode I or III loading. On the other hand, the corresponding values were closely matched indicating the mode III type loading turns into mode I for thin films. Aging was best manifested in the mode I -related EWF parameters, viz. specific yielding-related essential work and non-essential necking/tearing related work.

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Section: Introductionmentioning

confidence: 99%

In-plane and Out-of-plane Fracture Toughness of Physically Aged Polyesters as Assessed by the Essential Work of Fracture (EWF) Method

Bárány

Ronkay²,

Karger‐Kocsis³

et al. 2005

Int J Fract

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“…Such a treatment was successfully applied to all the specimens, which validates the method. The results obtained are displayed in Table 2 [19], respectively. The experimental data will be discussed in the following section.…”

Section: Resultsmentioning

confidence: 99%

“…It was first applied to metallic sheets [11][12][13], and then extended to polymers [14,15]. Many polymers have been characterized by this technique: polyethylene [14][15][16], polypropylene [17,18], polyamide 6 [19] and 6-6 [14,16], poly(ethylene terephthalate) and copolymers [16,[20][21][22][23][24][25][26][27][28][29], poly(ethylene naphthalate) [30,31], polycarbonate [32], etc. The EWF method is able to detect environment effects, such as hygrothermal aging in hygroscopic polymers like poly (ethylene terephthalate) [27,29].…”

Section: Introductionmentioning

confidence: 99%

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Relationships between processing conditions and mechanical properties of PA12 tubes. The EWF approach

et al. 2009

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International audienceIn polyamide 12 (PA12) tube extrusion, calibration is the key step of the process that affects the subsequent mechanical properties. In previous work it has been shown that according to the calibration conditions, a very oriented skin layer may be created, which has been correlated to an important decrease of elongation at break. In this paper, we present new results showing a good correlation between molecular orientation and fracture toughness, as evaluated by the EWF (Essential Work of Fracture) approach. They concern notched specimens and confirm the results obtained in classical tensile testing. The specific essential work of fracture is very sensitive to the orientation generated in the skin region by appropriate processing conditions: it decreases from the external to the inner regions of the tube, and increases with skin orientation

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“…Além dos fatores relacionados acima, estudos recentes em nossos laboratórios têm mostrado que a aplicabilidade do método EWF à poliamidas depende fortemente do método de preparação do entalhe e das condições de moldagem do corpo de prova [22] .…”

Section: Método Do Trabalho Essencial De Fratura (Ewf)unclassified

Tenacidade à fratura de blendas PA 6/ABS avaliada através do método EWF (Trabalho Essencial de Fratura) - parte a: avaliação do efeito do compatibilizante

Correa¹,

Yamakawa

Razzino

et al. 2007

Polímeros

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Resumo: A poliamida 6 (PA6) é um polímero termoplástico semicristalino que apresenta alta susceptibilidade ao entalhe quando solicitado mecanicamente. Apesar de apresentar um comportamento dúctil sob deformação e sob fratura quando solicitado sem entalhes, torna-se essencialmente frágil e quebradiço quando entalhado. Assim, o comportamento pseudodúctil dessas poliamidas requer cuidados especiais na confecção do entalhe e da pré-trinca para análise de seu comportamento mecânico. Devem ser observadas ainda as dimensões ideais dos corpos de prova para garantir a condição de estado de tensão plana no ensaio de tração uniaxial para aplicação do método EWF (Trabalho Essencial de Fratura). Neste trabalho, o método EWF foi utilizado para a avaliação da tenacidade à fratura de blendas poliméricas com uma matriz PA6 modificada com ABS e também a eficiência de um compatibilizante acrílico reativo (MMA-MA) sintetizado em laboratório, na tenacificação da blenda PA6/ABS. Através da aplicação do método observou-se que a simples incorporação do ABS à poliamida aumenta o termo relativo ao trabalho específico de fratura e reduz a sensibilidade ao entalhe da blenda embora com perda na capacidade de absorção de energia plástica. A incorporação do copolímero MMA-MA à blenda refletiu-se nos acréscimos do trabalho específico e recuperação da capacidade de absorção de energia plástica em relação à blenda não-compatibilizada. Os resultados ilustram a aplicabilidade do método EWF para determinação da tenacidade à fratura de blendas poliméricas em relação aos polímeros puros, bem como a avaliação do efeito do compatibilizante reativo na tenacidade da blenda PA6/ABS. Palavras-chave:Blendas poliméricas, poliamida 6, método EWF, tenacidade, compatibilização. Fracture Toughness of PA 6/Abs Evaluated by the EWF Method (Essential Work of Fracture) -Part A: On the Effect of the CompatibilizerAbstract: Polyamide 6 or polycaprolactam is a semi-crystalline thermoplastic whose toughness is very notch sensitive and consequently the material presents extreme susceptibility to stress concentrations. Thus, although such polyamides may fracture on a typical ductile manner on mechanical testing without notches, it will become brittle after being notched. The pseudo-ductile behavior in polyamides poses a task on notch and pre-crack preparation, for accurate assessment of their toughness. Furthermore, it must be observed the ideal specimen dimensions to guarantee plane stress conditions on tensile testing for application of the EWF (Essential Work of Fracture) method. In the present work, the EWF method was employed to evaluate the fracture toughness of PA6 blends modified with ABS and also to assess the efficiency of a self-made reactive acrylic compatibilizer (MMA-MA), on the toughness of the PA6/ABS blend. The EWF parameters have shown that by simply melt blending ABS with PA6 it increases the specific work of fracture owing to reduced notch sensitivity of the blend, although at the expenses of the blend capacity to absorb plastic energy. The addition of...

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Influence of notching and molding conditions on determination of EWF parameters in polyamide 6

Cited by 29 publications

References 19 publications

In-plane and Out-of-plane Fracture Toughness of Physically Aged Polyesters as Assessed by the Essential Work of Fracture (EWF) Method

In-plane and Out-of-plane Fracture Toughness of Physically Aged Polyesters as Assessed by the Essential Work of Fracture (EWF) Method

Relationships between processing conditions and mechanical properties of PA12 tubes. The EWF approach

Tenacidade à fratura de blendas PA 6/ABS avaliada através do método EWF (Trabalho Essencial de Fratura) - parte a: avaliação do efeito do compatibilizante

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