The Thermal Stability of Monosulfidic Crosslinks in Natural Rubber

1983 ◽  
Vol 56 (2) ◽  
pp. 337-343 ◽  
Author(s):  
G. P. McSwkeeney ◽  
N. J. Morrison

Abstract (1) Networks containing mainly monosuifidic crosslinks at methylene sites in the polyisoprene chains of natural rubber are expected to be more thermally stable than existing efficiently vulcanized networks. (2) Certain zinc-accelerator species promote the decomposition of crosslinks at high temperatures, but may be deactivated by complexation with zinc stearate (which is formed from stearic acid during vulcanization).

1992 ◽  
Vol 262 ◽  
Author(s):  
Kei-Yu Ko ◽  
S. Chen ◽  
G. Braunstein ◽  
L.-R. Zheng ◽  
S.-T. Lee

ABSTRACTUsing void-related compensation in Al-implanted GaAs, high-resistivity isolation regions that are thermally stable to high temperatures (> 700 °C) are demonstrated. The high-temperature thermal stability of the isolation regions allows the simplification of device processing in which a single high-temperature anneal (e.g., at 900 °C) can be used to activate the implant dopants in the device-active regions, and simultaneously to convert the Al-implanted regions highly resistive for electrical isolation. Other advantages of using void-related isolation will also be discussed.


Author(s):  
J. S. Mills ◽  
F. R. Edwards

The propensity of aviation turbine fuels to produce deposits in the oil-cooler and filter sections of aircraft fuel systems has been examined using a rig that simulates the fuel system of an aircraft and which employs realistic flow rates. All the fuels examined were found to be thermally stable up to temperatures in excess of those currently attained in engine oil coolers. Comparison with results obtained with the JFTOT indicates that this is not suited for use as a research tool.


2013 ◽  
Vol 469 ◽  
pp. 171-174 ◽  
Author(s):  
Ning Zhang ◽  
Si Yao Sui ◽  
Zhe Wang ◽  
Zhong Su Ma

Edible films were prepared using soy protein isolate (4g/100g), oleic acid (0-2g/100g) and stearic acid (0-2g/100g). Effects of the type and ratio of fatty acids (oleic acid and stearic acid) on the thermal properties of soybean protein isolate-based films were investigated. The results indicated that the addition of oleic acid and stearic acid take a significant effect on the thermal stability of soybean protein isolate-based films, as may attribute to that oleic acid is an amphiphilic substance that interacts with both polar and hydrophobic sites on proteins, thus it could improve the functional properties of the films. Besides, the solid state and hydrophobic nature of stearic acid could help limit water diffusion in the matrix more efficiently when it is well-integrated in the matrix through the surfactant action of oleic acid.


2016 ◽  
Vol 51 (4) ◽  
pp. 261-270
Author(s):  
FK Rony ◽  
SK Ray ◽  
A Hoque ◽  
M Asaduzzaman ◽  
S Sultana ◽  
...  

Galvanizing industries of Bangladesh produce profuse amount of environmentally hazardous solid waste materials like zinc dross which contains significant amount of valuable zinc and harmful heavy lead. Zinc was extracted as zinc chloride (ZnCl2) from zinc dross. Zinc stearate (ZnSt2) samples were prepared by precipitation method from stearic acid, sodium hydroxide and ZnCl2 by varying the amount of the reagents and product yield found within the range 96.06-99.18%. Characteristic peaks of ZnSt2 were investigated by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimeter (DSC) onset curve assigned accurate melting point within the range 122.84-124.03°C. Surface morphology of ZnSt2 was observed by Scanning Electron Microscope (SEM) and products had semi-crystalline structure. Thermal stability of ZnSt2 was evaluated by Thermo-gravimetric Analyzer (TGA) that complied with literature. A combination of ZnSt2 and Calcium stearate (CaSt2) at 1:1 ratio was used as thermal stabilizer in the powder commercial grade PVC resin and performed better thermal stability. The dehydrochlorination temperature of PVC with mixed stearates was 344.67±1.04°C for 10% (w/w) loading whereas for PVC, PVC with 10% (w/w) ZnSt2 and PVC with 10% (w/w) CaSt2, it was 269.83±1.04°C, 317.33±1.26°C and 323.33±2.08°C respectively.Bangladesh J. Sci. Ind. Res. 51(4), 261-270, 2016


2017 ◽  
Vol 864 ◽  
pp. 48-53
Author(s):  
Ahmad Fairoz Aziz ◽  
Khuzaimah Nazir ◽  
S.F. Ayub ◽  
N.I. Adam ◽  
Muhd Zu Azhan Yahya ◽  
...  

0.5 wt.% of N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine (6PPD) was introduced into polymer electrolytes based on 30% poly(methyl-methacrylate) grafted natural rubber (MG30) in order to reduce the aging factor of MG30. The polymer electrolyte without 6PPD was used as control. All samples were prepared by using solution cast techniques. The effect of 6PPD in the electrolytes was analysed by using TGA, DSC and FTIR. TGA and DSC results revealed the thermal stability of MG30 electrolytes with 6PPD have higher thermal stability but lower glass transition temperature value. FTIR studies confirmed the existence of LiTF in the sample and prove the occurrence of polymer-salt complexation. Deconvolution techniques analysis on FTIR spectra shows the electrolyte sample with 6PPD display more ion dissociation which reflects to higher ionic conductivity.


2008 ◽  
Vol 111 (2-3) ◽  
pp. 542-547 ◽  
Author(s):  
L. Fernández-Romero ◽  
J.M. Montero-Moreno ◽  
E. Pellicer ◽  
F. Peiró ◽  
A. Cornet ◽  
...  

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhi-Fen Wang ◽  
Si-Dong Li ◽  
Xin Fu ◽  
Hua Lin ◽  
Xiao-Dong She ◽  
...  

AbstractThe starch/natural rubber composite was prepared by blending the modified starch by esterification with natural rubber latex. The modified starch particles are homogenously distributed throughout the natural rubber (NR) matrix. In comparison with the host NR, the thermal stability of composite is significantly improved. The thermal degradation temperatures (T) and reaction activation energy (E) of composite are higher than those of the pure NR. The hardness, stress at 500%, tensile strength, permanent deformation and tear strength of composite increase linearly with the increment of dosage of modified starch.


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