Determination of fracture toughness of propylene polymers at different operating temperatures

Salazar, A.; Frontini, Patricia María; Rodrı́guez, J.

doi:10.1016/j.engfracmech.2014.04.023

Cited by 11 publications

(11 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…PP‐1 also shows these different regions; however, there is less depth of stress whitened area in Zone‐1. These three zones were also observed in previous studies by various researchers for PP; here, Zones 1, 2, and 3 were described as an outcome of slow stable crack growth, plastic deformation, and brittle fracture, respectively . In general, crazing is the main deformation process for PP, crazes appear and develop around the crack tip and proceed up to a certain point beyond which they cannot go further and this finally leads to rapid brittle fracture.…”

Section: Resultssupporting

confidence: 75%

“…The fracture toughness values measured in this work for PP‐1 and PP‐2 are very low compared to those published in literature for other manufacturing methods such as injection molding process. In injection molding process, 19 and 9 kJ/m 2 were reported for the PP random and block co‐polymers, respectively, as fracture toughness values . It must be noted that the materials tested in injection molding process differ in composition from the PP random and block co‐polymer (PP‐1 and PP‐2, respectively) tested in this work.…”

Section: Resultsmentioning

confidence: 72%

“…In load bearing and engineering applications for both PP and PE, an improved understanding of fracture behavior along with general strength analysis is considered necessary as it provides information on the crack growth process in the materials that can be directly relevant to their performance in real‐world conditions . Fracture toughness measurements using different fracture mechanics approaches and the identification of crack propagation mechanisms have been investigated by previous researchers , both for PP and PE, with the research focusing on injection or other molding processes. This type of detailed material analysis is still absent for rotationally molded PE and PP however.…”

Section: Introductionmentioning

confidence: 99%

“…From the fracture toughness analysis of injection and compression mold grade PP, it was found that the toughness is related to the initial notch depth, sample dimensions, temperature, and deformation rate .The application of linear elastic fracture mechanics (LEFM) to measure the fracture toughness of PP homopolymer is restricted to −60°C because of the excessive nonlinearity at higher temperatures . Therefore, the elastic–plastic fracture mechanics J‐integral method including multiple or single specimen normalization methods and the three‐parameter Weibull process were used at room temperature for PP homo and co‐polymers .…”

Section: Introductionmentioning

confidence: 99%

“…To investigate the effects of morphological parameters on fracture behavior and toughness properties, Charpy or Izod impact strength tests have also been conducted in the literature . The crystal structure, elastomeric content present in the copolymer, molecular weight, and so on are all believed to have an effect on the fracture toughness properties of PP . The effects of annealing to achieve higher toughness in PP were investigated by previous researchers .…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Fracture toughness of rotationally molded polyethylene and polypropylene

Saifullah¹,

Thomas

Cripps³

et al. 2017

Polymer Engineering & Sci

View full text Add to dashboard Cite

In this work, the fracture toughness of rotationally molded polyethylene (PE) and polypropylene (PP) was measured using J integral methods at static loading rates and at room temperature. Two different commercially available rotational molding grades PE and PP were tested in this study which have been used in various rotationally molded products such as small leisure craft, water storage tanks, and so on. Scanning electron microscope (SEM), optical microscope, differential scanning calorimetry (DSC), solidstate nuclear magnetic resonance (solid-state NMR), and X-ray scattering were used to investigate the microstructure, fracture surfaces, and compare toughness properties of these materials. In PE, higher molecular weight and broader molecular weight distribution, larger amorphous and crystal region thicknesses are found to be related to higher toughness values. High molecular weight favors higher number of entanglements that improve fracture energy and broader distribution increases long chain branching of higher molecular weight fractions which creates higher entanglements at the branch sites. Larger amorphous regions promote microvoiding more easily compared to thinner amorphous regions, leading to greater plastic deformation and energy absorption. Higher crystal thickness also contributes to microvoiding in the amorphous region. For PP, greater plastic deformation observed in the fracture surfaces is related to higher fracture toughness values. POLYM. ENG. SCI., 58:63-73, 2018.

show abstract

Section: Resultssupporting

confidence: 75%

Section: Resultsmentioning

confidence: 72%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Fracture toughness of rotationally molded polyethylene and polypropylene

Saifullah¹,

Thomas

Cripps³

et al. 2017

Polymer Engineering & Sci

View full text Add to dashboard Cite

show abstract

Influence of molecular structure and reinforcement on fatigue behavior of tough polypropylene materials

Arbeiter

Frank

Pinter

2016

J of Applied Polymer Sci

View full text Add to dashboard Cite

Molecular structure and reinforcement heavily influence the crack growth resistance of polypropylene materials. Aim of this study is to investigate the fatigue behavior of different unreinforced and reinforced tough polypropylene materials used for piping applications. Due to high resistance against crack growth, these materials cannot be tested in the application relevant quasi-brittle failure mode within feasible amounts of time. In this work, the new cyclic cracked round bar test, developed for tough polyethylene materials, has been examined as a possible method to characterize this important type of failure mode in homo-, random-, and reinforced polypropylene. Even though molecular mass distribution, which is often used to explain differences in crack growth resistance of polymers, was similar for unreinforced materials, fatigue lifetimes differed greatly. The mismatch of molecular mass and fatigue lifetime was mainly attributed to the different buildup and morphology of the base polymer. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43948.

show abstract