Nonisothermal crystallization kinetic study and thermal stability of multiwalled carbon nanotube reinforced poly(phenylene sulfide) composites

2015 ◽  
Vol 38 (3) ◽  
pp. 604-615 ◽  
Author(s):  
B. Ribeiro ◽  
L.R.O. Hein ◽  
M.L. Costa ◽  
P. Pötschke ◽  
T. Burkhart ◽  
...  
2017 ◽  
Vol 32 (1) ◽  
pp. 62-75 ◽  
Author(s):  
Bruno Ribeiro ◽  
LFP Santos ◽  
AL Santos ◽  
ML Costa ◽  
EC Botelho

Poly(ether-imide) (PEI)-based composites filled with multiwalled carbon nanotubes in a dispersed form (1.0 wt%) and as buckypaper (BP) (25 wt%) have been prepared by mixing solution and hot compression molding technique, respectively. Vacuum filtration technique with the aid of water-based surfactant Triton X-100 was employed to produce BP sheets. The thermal stability of the composites was evaluated by thermogravimetric analysis and revealed a strong increase in thermal degradation temperature when BPs were used as nanofiller. Ozawa–Wall–Flyn model was used to determine the kinetic parameters. It was observed an increase in activation energy as the nanotubes concentration rise, suggesting the formation of more thermally stable systems. In addition, half-life time as function of temperature demonstrated that BP-based composites could operate for 3200 years at 200°C. These results concluded that carbon nanotube BP could contribute to improve significantly the thermal stability of PEI matrix.


2016 ◽  
Vol 49 (2) ◽  
pp. 99-119 ◽  
Author(s):  
Saowaroj Chuayjuljit ◽  
Piyaphorn Mungmeechai ◽  
Anyaporn Boonmahitthisud

Epoxidized natural rubber (ENR)/multiwalled carbon nanotube (MWCNT) nanocomposites were prepared via in situ epoxidation of natural rubber (NR) using a molar ratio of formic acid/hydrogen peroxide to isoprene unit at 0.75/0.75 with five loadings of MWCNTs, ranging from 0.5–2.5 parts per hundred parts of rubber (phr), at 50°C for 4 h. Based on Fourier transform infrared spectra, the epoxide content of ENR in the nanocomposites was about 32.5–33.2 mole%. Accordingly, the products were referred to ENR30/MWCNT nanocomposites. The curing characteristics, mechanical properties (tensile properties, tear strength, and hardness), glass transition temperature ( Tg), thermal stability, and oil resistance of these in situ ENR30/MWCNT nanocomposites were investigated and compared with NR and neat ENR30. The results showed that the scorch and cure times of ENR30/MWCNT nanocomposites were the longest followed by NR and ENR30. The incorporation of an appropriate amount of MWCNTs into the in situ epoxidation apparently improved the properties of NR. Among them, the nanocomposites filled with 2 phr MWCNTs exhibited the highest mechanical properties, Tg, thermal stability, and oil resistance. The mechanical properties of the in situ nanocomposites were also compared with those of the control nanocomposites prepared by adding MWCNTs directly in the prepared ENR30 latex. It was found that at similar MWCNT loadings, the in situ nanocomposites exhibited higher mechanical properties than the control nanocomposites.


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