scholarly journals Influence of Graphene Platelet Aspect Ratio on the Mechanical Properties of HDPE Nanocomposites: Microscopic Observation and Micromechanical Modeling

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1719
Author(s):  
Evangelia Tarani ◽  
Iouliana Chrysafi ◽  
Alfréd Kállay-Menyhárd ◽  
Eleni Pavlidou ◽  
Thomas Kehagias ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Filler Content ◽  
Graphene Nanoplatelets ◽  
Micromechanical Modeling ◽  
Melt Mixing ◽  
Percolation Effect ◽  
Mixing Method ◽  
Micro Deformation ◽  
Prediction Of Mechanical Properties

A series of high-density polyethylene nanocomposites filled with different diameter sizes (5, 15, and 25 μm) of graphene nanoplatelets at various amounts (0.5–5 wt.%) are prepared by the melt-mixing method. The effect of diameter size and filler content on the mechanical properties is reported, and the results are discussed in terms of morphology and the state of dispersion within the polymer matrix. The measured stiffness and strength of the nanocomposites were found to be mainly influenced by the filler aspect ratio and the filler-matrix adhesion. Fractography was utilized to study the embrittleness of the nanocomposites, and the observations revealed that a ductile to brittle transition is caused by a micro-deformation mechanism change in the nanocomposites. Several micromechanical models for the prediction of mechanical properties of nanocomposites, taking into consideration filler aspect ratio, percolation effect, and interphase regions, are considered. The three-phase model proposed by Ji accurately predicts the stiffness of graphene nanoplatelets with a higher diameter size, while Takayanagi modified model II was found to show good agreement with the experimental results of smaller ones at low filler content. This study demonstrates that the diameter size of the filler plays a central role in determining the mechanical properties.

Evaluation of mechanical and dynamic mechanical properties of multiwalled carbon nanotube-based ethylene–propylene copolymer composites mixed by masterbatch dilution

2016 ◽  
Vol 50 (29) ◽  
pp. 4093-4101 ◽  
Author(s):  
Maija Hoikkanen ◽  
Minna Poikelispää ◽  
Amit Das ◽  
Uta Reuter ◽  
Wilma Dierkes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Aspect Ratio ◽  
Melt Mixing ◽  
Multiwalled Carbon ◽  
Mixing Processes ◽  
Ethylene Propylene ◽  
Dynamic Mechanical ◽  
Mixing Method

A two-step masterbatch mixing technique was studied for preparation of carbon nanotube-filled ethylene–propylene diene elastomer compounds, and compared to conventional one-step mixing process. In the two-step process, a masterbatch compound with carbon nanotube content of 50 parts per hundred was prepared by melt-mixing ethylene–propylene diene elastomer. This material was then compounded with pristine ethylene–propylene diene elastomer and composites with different carbon nanotube concentrations were compared. The aim of this study is to compare the efficiency of two different mixing processes on the dispersion of carbon nanotubes and to facilitate the handling of carbon nanotubes, as the masterbatch can be prepared in a controlled way and used for further dilution without the problems related to carbon nanotube processing. The compound properties were studied with emphasis on mechanical characterization and dynamic mechanical thermal analysis. Masterbatch mixing resulted in the similar mechanical properties of the composites compared to the direct mixing method. At the relatively low loadings of carbon nanotubes, the considerable improvements of the mechanical properties were observed. The aspect ratio of the carbon nanotubes determined by transmission electron microscope was found to be similar to the one calculated from the Guth equation. It showed a considerable reduction in aspect ratio independent of the used mixing method.

scholarly journals On the Improved Mechanical Properties of Ball-Milled GNPs Reinforced Short Chain Branched-Polyethylene Nanocomposite: Micromechanical Modeling and Fractography Study

2021 ◽  
Vol 11 (20) ◽  
pp. 9420
Author(s):  
Dimitra Kourtidou ◽  
Konstantinos Tsongas ◽  
Maria-Eirini Grigora ◽  
Dimitrios Tzetzis ◽  
Dimitrios N. Bikiaris ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ball Milling ◽  
Filler Content ◽  
Milling Process ◽  
Short Chain ◽  
Micromechanical Modeling ◽  
Melt Mixing ◽  
Crystallinity Degree ◽  
Branched Polyethylene ◽  
Ball Milling Process

Short-chain branched-Polyethylene (SCB-PE) is commonly utilized in hot and cold piping systems due to its high-temperature resistance. SCB-PE nanocomposites using graphene nanoplatelets (GNPs) as a reinforcing filler were synthesized in this work. The effect of the filler’s content and the ball-milling process on nanocomposites’ structure, tensile and shear properties was studied. Two series of nanocomposites have been prepared, one with and one without the ball-milling as a premixing step prior to the melt-mixing process. The ball-milling process induced a lower crystallinity degree of the SCB-PE nanocomposites than their solely melt-mixed counterpart. The tensile properties of the ball-milled samples presented a more profound enhancement with increasing filler content. The Ji and modified Halpin-Tsai micromechanical models were best fit to describe the experimental elastic modulus of the solely melt-mixed and the ball-milled nanocomposites, respectively. Fractography studies suggested that the detachment of the filler particles from the polymer matrix is avoided for lower GNPs contents of the ball-milled samples. Shear tests revealed that the shear strength increased and ductility decreased with increasing filler content in any case. The ball-milling process resulted in SCB-PE nanocomposites with superior mechanical properties compared to their solely melt-mixed counterparts.

Mixing Methods Influencing on Properties of Epoxidized Natural Rubber/Polypropylene Thermoplastic Vulcanizates

2013 ◽  
Vol 844 ◽  
pp. 109-112 ◽  
Author(s):  
Chesidi Hayichelaeh ◽  
Charoen Nakason ◽  
Anoma Thitithammawong
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Dynamic Mechanical Properties ◽  
Epoxidized Natural Rubber ◽  
Melt Mixing ◽  
Dynamic Mechanical ◽  
Thermoplastic Vulcanizates ◽  
Mixing Method ◽  
Internal Mixer

Epoxidized natural rubber (ENR)/Polypropylene (PP) thermoplastic vulcanizates were prepared by melt mixing method in an internal mixer. Influences of different mixing methods for incorporation of processing oil into the TPVs on tensile and dynamic mechanical properties of the TPVs and crystallinity of the PP were investigated. Results show that distribution of processing oil in the ENR/PP TPV is important due to the processing oil can promote and in the same time can interrupt an improvement in elastomeric properties of the TPV. Incorporation of processing oil into the ENR phase by preparation of oil extended ENR (the mixing method 1) before mixing with the PP was the better way to produce the TPV. It promoted the TPV with superior tensile and dynamic mechanical properties than the TPVs prepared from the mixing method 2 and 3 in which the processing oil was directly added into the PP phase. Furthermore, the TPV from the mixing method 1 had less effect of processing oil on the PP crystallization.

scholarly journals The Role of Interfacial Interactions on the Functional Properties of Ethylene–Propylene Copolymer Containing SiO2 Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2308
Author(s):  
Iman Taraghi ◽  
Sandra Paszkiewicz ◽  
Izabela Irska ◽  
Krzysztof Pypeć ◽  
Elżbieta Piesowicz
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Sio2 Nanoparticles ◽  
Interfacial Interactions ◽  
Melt Mixing ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Optically Transparent ◽  
Mixing Method

In this paper, the mechanical properties, thermal stability, and transparency of ethylene–propylene copolymer (EPC) elastomer modified with various weight percentages (1, 3, and 5 wt.%) of SiO2 nanofillers have been studied. The nanocomposites were prepared via a simple melt mixing method. The morphological results revealed that the nanofillers were uniformly dispersed in the elastomer, where a low concentration of SiO2 (1 wt.%) had been added into the elastomer. The FTIR showed that there are interfacial interactions between EPC matrix and silanol groups of SiO2 nanoparticles. Moreover, by the addition of 1 wt.% of SiO2 in the EPC, the tensile strength and elongation at break of EPC increased by about 38% and 27%, respectively. Finally, all samples were optically transparent, and the transparency of the nanocomposites reduced by increasing the content of SiO2 nanoparticles.

scholarly journals Multiscale Modeling of Epoxy-Based Nanocomposites Reinforced with Functionalized and Non-Functionalized Graphene Nanoplatelets

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1958
Author(s):  
Hashim Al Mahmud ◽  
Matthew S. Radue ◽  
Sorayot Chinkanjanarot ◽  
Gregory M. Odegard
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Aspect Ratio ◽  
Mechanical Response ◽  
Nanocomposite Materials ◽  
Graphene Nanoplatelets ◽  
Pristine Graphene ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
The Impact

The impact on the mechanical properties of an epoxy resin reinforced with pristine graphene nanoplatelets (GNP), highly concentrated graphene oxide (GO), and functionalized graphene oxide (FGO) has been investigated in this study. Molecular dynamics (MD) using a reactive force field (ReaxFF) has been employed in predicting the effective mechanical properties of the interphase region of the three nanocomposite materials at the nanoscale level. A systematic computational approach to simulate the reinforcing nanoplatelets and probe their influence on the mechanical properties of the epoxy matrix is established. The modeling results indicate a significant degradation of the in-plane elastic Young’s (decreased by ~89%) and shear (decreased by ~72.5%) moduli of the nanocomposite when introducing large amounts of oxygen and functional groups to the robust sp2 structure of the GNP. However, the wrinkled morphology of GO and FGO improves the nanoplatelet-matrix interlocking mechanism, which produces a significant improvement in the out-of-plane shear modulus (increased by 2 orders of magnitudes). The influence of the nanoplatelet content and aspect ratio on the mechanical response of the nanocomposites has also been determined in this study. Generally, the predicted mechanical response of the bulk nanocomposite materials demonstrates an improvement with increasing nanoplatelet content and aspect ratio. The results show good agreement with experimental data available from the literature.

scholarly journals Welding Behaviour of Graphene Oxide Reinforced High Density Polyethylene Nanocomposites

2019 ◽  
Vol 9 (1) ◽  
pp. 3211-3215
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Base Material ◽  
Body Part ◽  
The Body ◽  
Weld Strength ◽  
Bonded Joints ◽  
Compression Moulding ◽  
Melt Mixing ◽  
Mixing Method

Welding is used to produce bonded joints with technical properties to the base material. The thermoplastic nanocomposites are more familiar in recent days due to their excessive automotive applications. The specimens were prepared by pure HDPE and various weight ratios HDPE with nanofiller composites by melt mixing method and required shape produced by using compression moulding. The nanofiller will be chosen in this study is Graphene oxide. The main scope of using Graphene oxide was to enhance the mechanical properties of the prepared specimens. In this work, Ultrasonic welding had been used to carry out the test on both pure HDPE and HDPE with grapheme oxide. Mechanical properties were analyzed for both pure HDPE and grapheme oxide filled HDPE of both body part and welded part joints are compared.The mechanical properties of tensile strength and youngs modulus and elongation of the body part for graphene oxide filled HDPE was substantially increased due to the presence of compatabilizer.Thus the result improves the weld strength of the nanofilled polymer matrix with compatabilizer

scholarly journals Synthesis and study on mechanical properties of the polypropylene/TiO2 - nano Ag composite for antibacterial application

2015 ◽  
Vol 18 (1) ◽  
pp. 70-80
Author(s):  
Luan Nguyen Thanh Huynh ◽  
Cuong Chi Huynh ◽  
Nhan Thuc Chi Ha ◽  
Vinh Quang Lam ◽  
Hieu Van Le
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Average Particle Size ◽  
Chemical Compositions ◽  
Average Particle ◽  
Melt Mixing ◽  
E Coli ◽  
Transmission Electron ◽  
Mixing Method ◽  
Polypropylene Matrix

In this study, PP/TiO2 – nano Ag composite were successfully prepared by melt mixing method. The composites TiO2 – nano Ag and PP/TiO2 – nano Ag with different silver content were characterized by scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Xray diffraction (XRD) and IR spectrum to investigate their morphology and chemical compositions. It was found that the silver nanoparticles in TiO2 matrix were uniformly distributed and strongly attached to the polypropylene matrix and the average particle size of TiO2 – nano Ag was from 30 to 60 nm. As the result, the antibacterial property was obtained via microorganism test by showing the elimination of more than 99 % of E. coli bacteria. And UV protection behavior was also observed by UV-Vis characterization. In the other hand, the mechanical properties of polypropyleneTiO2-nano Ag composite were noticeably improved as compared to the neat polypropylene.

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