Investigation of Mixing Processes of Polymer Composites

2012 ◽  
Vol 729 ◽  
pp. 332-337
Author(s):  
G. Dogossy ◽  
E. Sági ◽  
Ferenc Ronkay

Three ultrahigh molecular weight polyethylene (UHMWPE) composites of differing composition, reinforced with multiwalled carbon nanotubes (MWCNT) were prepared. The homogeneous distribution of MWCNT has been attempted by two dry blending methods and one melt-mixing process. The efficiency of the various methods was characterized by their effects on the quasi-static and dynamic physical properties of the composites. In the case of composites manufactured by ball milling the effects of various adhesion promoter additives (compatibilizers) has also been studied by analyzing the tensile, flexural, Charpy impact and wear properties of the composites.

2016 ◽  
Vol 50 (29) ◽  
pp. 4093-4101 ◽  
Author(s):  
Maija Hoikkanen ◽  
Minna Poikelispää ◽  
Amit Das ◽  
Uta Reuter ◽  
Wilma Dierkes ◽  
...  

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.


Author(s):  
Lailesh Kumar ◽  
Santosh Kumar Sahoo ◽  
Syed Nasimul Alam

Abstract In the present investigation, Cu-multiwalled carbon nanotubes (MWCNTs) nanocomposites were developed through mechanical milling using nanostructured Cu as a matrix and MWCNTs as nanofillers. The influence of nanostructured Cu on the microstructure, microhardness, and wear behavior of Cu-MWCNTs nanocomposites was also studied. The crystallite size of nanostructured Cu powder via mechanical milling for 25 h was found to be 16 nm. The major challenge associated with the development of Cu-MWCNTs nanocomposites is the uniform dispersion of the CNTs in the Cu matrix, which was addressed by incorporating nanostructured Cu, leading to the homogeneous distribution of CNTs and good bonding between the CNTs and the Cu matrix. A significant improvement in relative density and microhardness with <3 wt.% MWCNTs was observed compared to pure asreceived Cu and its composites. The hardness of Cu-3 wt.% MWCNTs nanocomposite developed using nanostructured Cu were achieved at <800 MPa, which is about 2.3 times higher than that of the as-received Cu sample (~ 359 MPa). The significant increment in mechanical and wear properties mainly originates from fine-grain strengthening effects and solid solution strengthening. The wear mechanisms in the various nanostructured Cu-MWCNTs composites were studied in detail and oxidation wear was identified as one of the main wear mechanisms.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Halil Ibrahim Kurt ◽  
Murat Oduncuoglu

In the current study, the effect of applied load, sliding speed, and type and weight percentages of reinforcements on the wear properties of ultrahigh molecular weight polyethylene (UHMWPE) was theoretically studied. The extensive experimental results were taken from literature and modeled with artificial neural network (ANN). The feed forward (FF) back-propagation (BP) neural network (NN) was used to predict the dry sliding wear behavior of UHMWPE composites. Eleven input vectors were used in the construction of the proposed NN. The carbon nanotube (CNT), carbon fiber (CF), graphene oxide (GO), and wollastonite additives are the main input parameters and the volume loss is the output parameter for the developed NN. It was observed that the sliding speed and applied load have a stronger effect on the volume loss of UHMWPE composites in comparison to other input parameters. The proper condition for achieving the desired wear behaviors of UHMWPE by tailoring the weight percentage and reinforcement particle size and composition was presented. The proposed NN model and the derived explicit form of mathematical formulation show good agreement with test results and can be used to predict the volume loss of UHMWPE composites.


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