scholarly journals Surface modification of YS-20 with polydopamine for improving the tribological properties of polyimide composites

Friction ◽  
2021 ◽  
Author(s):  
Liangfei Wu ◽  
Zhaozhu Zhang ◽  
Mingming Yang ◽  
Junya Yuan ◽  
Peilong Li ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Tribological Properties ◽  
Metallic Copper ◽  
Great Effort ◽  
Modified Polymer ◽  
Milling Method ◽  
Multi Walled Carbon Nanotubes ◽  
Mixing Method ◽  
Walled Carbon Nanotubes ◽  
Polymer Powders

AbstractRecently, great effort has been devoted to prepare various reinforce fillers to improve polymer performances, but ignoring the importance of raw polymer powders which are indispensable parts of hot-pressed polymer composites. Herein, we engineer raw polyimide (PI) powders with the assistance of polydopamine (PDA) in aqueous solutions. After the modification, polymer powders change from hydrophobic to hydrophilic, which makes it is possible to further modification of polymer powders in liquid phase. During the curing process of modified polymer powders, the partial dehydration of the catechol groups and crosslinking of PDA via C-O-C bonds are confirmed. Based on the features of PDA, a non-destructive mixing method is utilized to realize homogeneous dispersion of multi-walled carbon nanotubes (MWCNTs) in polymer matrix. In comparison with ball milling method, this way can preserve the integrated innate structure of MWCNTs effectively. Besides, by taking full advantage of the reducing and metal-coordination capability of PDA, Cu2+ is successfully loaded onto the surfaces of polymer powders. The related characterizations demonstrate that Cu2+in situ converts to metallic copper rather than copper oxide during the hot pressing process. The tribological properties of corresponding polymer composites are also studied. These results indicate that modifying polymer powders with PDA is multi-profit and presents practical application prospect.

scholarly journals The effect of the surface modification of carbon nanotubes on their dispersion in the epoxy matrix

2011 ◽  
Vol 13 (2) ◽  
pp. 62-69 ◽  
Author(s):  
Maria Wladyka-Przybylak ◽  
Dorota Wesolek ◽  
Weronika Gieparda ◽  
Anna Boczkowska ◽  
Ewelina Ciecierska
Keyword(s):  
Carbon Nanotubes ◽  
Surface Modification ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Mechanical Mixing ◽  
Weight Percentage ◽  
Homogeneous Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Mixing Method ◽  
Walled Carbon Nanotubes

The effect of the surface modification of carbon nanotubes on their dispersion in the epoxy matrix Functionalization of multi-walled carbon nanotubes (MWCNTs) has an effect on the dispersion of MWCNT in the epoxy matrix. Samples based on two kinds of epoxy resin and different weight percentage of MWCNTs (functionalized and non-functionalized) were prepared. Epoxy/carbon nanotubes composites were prepared by different mixing methods (ultrasounds and a combination of ultrasounds and mechanical mixing). CNTs modified with different functional groups were investigated. Surfactants were used to lower the surface tension of the liquid, which enabled easier spreading and reducing the interfacial tension. Solvents were also used to reduce the liquid viscosity. Some of them facilitate homogeneous dispersion of nanotubes in the resin. The properties of epoxy/nanotubes composites strongly depend on a uniform distribution of carbon nanotubes in the epoxy matrix. The type of epoxy resin, solvent, surfactant and mixing method for homogeneous dispersion of CNTs in the epoxy matrix was evaluated. The effect of CNTs functionalization type on their dispersion in the epoxy resins was evaluated on the basis of viscosity and microstructure studies.

Two-step synthesis of polyurethane/multi-walled carbon nanotubes polymer composite to achieve high percentage particle reinforcement for mechanical applications

2021 ◽  
pp. 002199832199945
Author(s):  
Dinesh Kumar ◽  
Suneev Anil Bansal ◽  
Navin Kumar ◽  
Prashant Jindal
Keyword(s):  
Carbon Nanotubes ◽  
Synthesis Method ◽  
Step Method ◽  
Molding Method ◽  
Uniform Dispersion ◽  
Noticeable Improvement ◽  
Multi Walled Carbon Nanotubes ◽  
Mixing Method ◽  
Compressive Testing ◽  
Walled Carbon Nanotubes

The present work has been aimed to synthesize Polyurethane (PU)/Multi-Walled Carbon Nanotubes (MWCNTs) composite using a two-step method to enhance mechanical properties. In the first step, films (0.2 mm thickness) have been synthesized using a solution mixing method to disperse MWCNTs in the PU matrix. In the second step, thin films of uniformly dispersed MWCNTs in the PU matrix have been compression molded to synthesize PU/MWCNTs composite required for real mechanical applications. The two-step method has the advantages of solution mixing as well as compression molding method. The results of quasi-static nanoindentation tests indicated that in comparison to pure PU, elastic modulus and hardness have been enhanced by 124% and 53% respectively for 10 wt% PU/MWCNTs composite. Fracture resistance of PU/MWCNTs composites, with 7 wt% of MWCNTs, has been enhanced by 52% as compared to pure PU. To understand bulk behavior, nanoindentation results have been cross-verified with compression testing. Results of compressive testing shown that the modulus of composite material has been significantly improved under the influence of the increasing composition of MWCNTs. A noticeable improvement of 52% has been observed in compressive modulus of 10 wt% composite in equivalence to pure PU. The overall improvement in mechanical behavior has been attributed to the uniform dispersion of MWCNTs in the PU matrix by the two-step synthesis method.

The influence of functionalization time of carbon nanotube on the mechanical properties of the epoxy composites

2017 ◽  
Vol 51 (12) ◽  
pp. 1693-1701 ◽  
Author(s):  
EA Zakharychev ◽  
EN Razov ◽  
Yu D Semchikov ◽  
NS Zakharycheva ◽  
MA Kabina
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Composite Materials ◽  
Polymer Composites ◽  
Epoxy Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This paper investigates the structure, length, and percentage of functional groups of multi-walled carbon nanotubes (CNT) depending on the time taken for functionalization in HNO3 and H2SO4 mixture. The carbon nanotube content and influence of functionalization time on mechanical properties of polymer composite materials based on epoxy matrix are studied. The extreme dependencies of mechanical properties of carbon nanotube functionalization time of polymer composites were established. The rise in tensile strength of obtained composites reaches 102% and elastic modulus reaches 227% as compared to that of unfilled polymer. The composites exhibited best mechanical properties by including carbon nanotube with 0.5 h functionalization time.

The Effect of CNT Content on the Tribological Properties of CNTs Doped Diamond-Like Carbon Films

2015 ◽  
Vol 642 ◽  
pp. 231-235
Author(s):  
Che Hung Wei ◽  
Jui Feng Yang ◽  
Chao I Wang
Keyword(s):  
Friction Coefficient ◽  
Critical Load ◽  
Internal Stress ◽  
Tribological Properties ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Element Analysis ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Diamond-like carbon (DLC) films is useful in many applications. To improve the tribological properties in DLC, we spin coat the multi-walled carbon nanotubes (CNTs) with different solution on (100) silicon. DLC was deposited by plasma enhanced chemical vapor deposition (PECVD) with C2H2and H2. The results show that the ID/IGratio is increasing with higher CNTs content while the friction coefficient and critical load are decreasing with larger CNTs contents. The decreasing friction coefficient results from graphitation on the surface due to higher sp2content. The decreasing critical load is attributed to higher internal stress. The effect of friction coefficient and CNT concentration on stress distribution is studied by a nanoscratch finite element analysis. The results indicate that low friction coefficient and high CNT concentration will reduce the stress magnitude in the film. Therefore, the decreasing friction coefficient in CNT doped DLC film with increasing CNT concentration should reduce stress in the film and is good for adhesion. The discrepancy between friction coefficient and critical load is explained in terms of high internal stress during deposition. A surface treatment on CNT before deposition to reduce internal stress is currently under investigation.

Development of Carbon Nanotube Reinforced Conductive Polymer Composites for PEM Fuel Cells

2012 ◽  
Vol 729 ◽  
pp. 260-265
Author(s):  
M. Olah ◽  
Ferenc Ronkay
Keyword(s):  
Electrical Conductivity ◽  
Polymer Composites ◽  
Filler Content ◽  
Conductive Polymer ◽  
High Viscosity ◽  
Pem Fuel Cells ◽  
Conductive Polymer Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Matrix Compound ◽  
Walled Carbon Nanotubes

Investigation of conductive polymer composites have been carried out using polypropylene (PP) and polyphenylene sulfonate (PPS) for matrix compound and graphite, carbon black and multi walled carbon nanotubes (MWCNT) for fillers. The comparison of these matrix materials with respect to the resulting electrical conductivity were investigated in depth. The effect of quantity of nanotubes and their dispersion on electrical conductivity and formability was also investigated. It has been found that PPS composites show much higher conductivity, however the high temperature needed for forming, and high viscosity in case of high filler content (50 wt% <) make the processing difficult, therefore the injection molding of the resulting material is currently not possible. Furthermore in contradiction to the literature the addition of MWCNT did not raise the conductivity significantly, therefore the focus have been kept on filler content instead.

Tribological properties of Ni–P-multi-walled carbon nanotubes electroless composite coating

2003 ◽  
Vol 57 (7) ◽  
pp. 1256-1260 ◽  
Author(s):  
W.X Chen ◽  
J.P Tu ◽  
Z.D Xu ◽  
W.L Chen ◽  
X.B Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Composite Coating ◽  
Tribological Properties ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes
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