End pressure effects of polypropylene composites reinforced with multi-walled carbon nanotubes in capillary flow

2019 ◽  
pp. 089270571987058
Author(s):  
Ji-Zhao Liang

The influence of the size and content of multi-walled carbon nanotubes (MWCNTs) on the end pressure effects of polypropylene (PP) composite melts during capillary extrusion flow was investigated, with the test temperature varying from 190°C to 230°C and apparent shear rate ranging from 50 s−1 to 3000 s−1. The results showed that the end pressure drop increased with increasing apparent shear rates, while decreased with increasing test temperature, and the sensitivity of the end pressure drop to apparent shear rate for the composites was higher than that for the unfilled PP. The end pressure drop increased with increasing weight fraction and the specific surface area of the MWCNTs. The end pressure drop increased almost linearly with increasing the aspect ratio of the MWCNTs. Moreover, the end pressure effect mechanisms of the composite melts during a capillary extrusion flow were discussed.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hadi Pourpasha ◽  
Saeed Zeinali Heris ◽  
Yaghob Mohammadfam

AbstractThis research aims of compare the impact of the mass fraction of multi-walled carbon nanotubes (MWCNTs) and titanium dioxide (TiO2) nano additive on the tribological and thermophysical attributes of turbine meter oil. These attributes include the average friction coefficient, pressure drop, wear, flash point, pour point, relative viscosity, kinematics viscosity, and viscosity index. The pressure drops and the average friction coefficient inside the copper tube were simulated and compared with experimental results. In this study, for the synthesis of nano lubricants from turbine meter oil as a pure fluid and from MWCNTs and TiO2 as nano additives in the mass fraction of 0.05, 0.1, 0.2, 0.3, and 0.4 wt.% and from oleic acid and Triton x100 as surfactants were utilized. The results illustrated that the wear depth of copper pins in the presence of nano lubricant with 0.4 wt.% of MWCNTs and 0.1 wt.% TiO2 was improved by 88.26% and 71.43%, respectively. Increasing 0.3 wt.% of TiO2 and MWCNTs into the oil caused to improvement in viscosity index. The simulation data and experimental data for the pressure drop were closer together and indicated a minor error that the maximum error is less than 10%.


2020 ◽  
Author(s):  
Hadi Pourpasha ◽  
Saeed Zeinali Heris ◽  
Yaghob Mohammadfam

Abstract This research work purpose to compare the impact of the mass fraction of multi-walled carbon nanotubes (MWCNTs) and Titanium dioxide (TiO2) nano additive on the tribological and thermophysical attributes of turbine meter oil. These attributes are including the average friction coefficient, pressure drop, wear, flash point, pour point, relative viscosity, kinematics viscosity, and viscosity index. Also, the pressure drops and the average friction coefficient inside the copper tube were simulated and compared with experimental results. In this study, for the synthesis of nano lubricants from turbine meter oil as a pure fluid and from MWCNTs and TiO2 as nano additives in the mass fraction of 0.05, 0.1, 0.2, 0.3, and 0.4 wt.% and from oleic acid and Triton x100 as surfactants were utilized. The diameter of MWCNTs and TiO2 nano additives were ranging from 5 nm to 16.1 nm and 7.9 nm to 13.9 nm, respectively. The average particle size of TiO2 and MWCNTs nano additives in 0.4 wt.% in the pure lubricant were 221 nm and 320 nm, respectively. The results illustrated that the wear depth of copper pins in the presence of nano lubricant with 0.4 wt.% of MWCNTs and 0.1 wt.% TiO2 was improved by 88.26% and 71.43%, respectively. Nano lubricants with 0.3 wt.% of TiO2 and 0.4 wt.% of MWCNTs nano additives illustrated the maximum improvement in the flash point temperature with enhancement 4 °C and 10 °C. By increasing of 0.3 wt.% of TiO2 and MWCNTs into the pure oil caused to improve in viscosity index with enhancement 6.68% and 2.43% compared to the pure lubricant, respectively. The simulation data and experimental data for the pressure drop were closer together and indicated a minor error that the maximum error is less than 10%.


Acta Naturae ◽  
2011 ◽  
Vol 3 (1) ◽  
pp. 99-106 ◽  
Author(s):  
E A Smirnova ◽  
A A Gusev ◽  
O N Zaitseva ◽  
E M Lazareva ◽  
G E Onishchenko ◽  
...  

2003 ◽  
Vol 772 ◽  
Author(s):  
T. Seeger ◽  
G. de la Fuente ◽  
W.K. Maser ◽  
A.M. Benito ◽  
A. Righi ◽  
...  

AbstractCarbon nanotubes (CNT) are interesting candidates for the reinforcement in robust composites and for conducting fillers in polymers due to their fascinating electronic and mechanical properties. For the first time, we report the incorporation of multi walled carbon nanotubes (MWNTs) into silica-glass surfaces by means of partial surface-melting caused by a continuous wave Nd:YAG laser. MWNTs were detected being well incorporated in the silica-surface. The composites are characterized using scanning electron microscopy (SEM) and Raman-spectroscopy. A model for the composite-formation is proposed based on heatabsorption by MWNTs and a partial melting of the silica-surface.


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