The Influence of Carbon Black on the Reversion Process in Sulfur-Accelerated Vulcanization of Natural Rubber

1982 ◽  
Vol 55 (1) ◽  
pp. 103-115 ◽  
Author(s):  
C. H. Chen ◽  
J. L. Koenig ◽  
J. R. Shelton ◽  
E. A. Collins

Abstract The effect of carbon black upon the reversion process in the sulfur-accelerated vulcanization of natural rubber has been studied. It is found that black-filled cure systems have a faster rate of vulcanization and better reversion resistance. The net decrease of trans-methine content, which is equivalent to the improvement of reversion resistance, is found to be at most 15%, with the initial 10 pphr loading yielding the greatest effect. However, those decreases of trans-methine content are small when compared with the substantial effects of these fillers on the physical-mechanical properties of the vulcanizate, which is a linear function of black loading. In general, the smaller the black particle size, the greater the improvement of the reversion resistance, but particle size alone is not the only factor affecting reversion. A universal curve is obtained for correlating the amount of reversion and trans-methine content, which is independent of any natural rubber-based curing system, operating conditions and type of fillers.

2012 ◽  
Vol 626 ◽  
pp. 114-120 ◽  
Author(s):  
Mahendra Anggaravidya ◽  
Sudirman Sudirman ◽  
Bambang Soegijono ◽  
Emil Budianto ◽  
Martin Djamin

The mechanical properties of natural rubber can be enhanced by the addition of carbon black. The mechanical properties change is highly affected by particle size and carbon black structure used. A modification of N660 carbon black was conducted in the research by sonoficating the carbon black for 3 and 5 hours (N600-M3; M5). The results of adding modified carbon black were characterised by Particle Size Analysis (PSA), Scanning Electron Microscopes - Energy Dispersive Spectrometry (SEM-EDS) and Thermogravimetric Analysis (TGA). The addition of modified carbon black shows bound rubber, thermal properties, and mechanical properties such as tensile strength, elongation at break and modulus 300% on the vulcanisate produced were increased from the vulcanisate that had been filled with N660 natural (N660-N). Keywords: natural rubber, carbon black, particle size, sonofication, characterisation


2015 ◽  
Vol 88 (3) ◽  
pp. 412-420 ◽  
Author(s):  
Huan Zhang ◽  
Zhiyi Zhang ◽  
Guizhe Zhao ◽  
Yaqing Liu ◽  
Ye Li ◽  
...  

ABSTRACT Carbon black and silica have long been recognized as reinforcing fillers, but their effect on the dynamic properties and heat buildup of vulcanizates is rarely reported. Therefore, natural rubber composites filled by carbon black with different particle size and silica were prepared. The Payne effect and heat buildup progressively decrease with an increase of carbon black particle size because of weaker filler network structure and better dispersion, the N754 filled sample in particular shows the lowest value, only 4.7 °C. The tensile strength and tear strength of composites all increase with the reducing carbon black particle size. SiO2-filled composites exhibit obvious Payne effects and inferior mechanical properties; at high strains (>10%), tan δ of SiO2-filled composites surpasses all that of carbon black–filled composites, due to the surface silanol groups on the silica surface and due to the decreased cross-link density.


Author(s):  
Yayoi Akahori ◽  
Misao Hiza ◽  
Soki Yamaguchi ◽  
Seiichi Kawahara

ABSTRACT Protein effect on vulcanization of NR, obtained from Hevea brasiliensis, was investigated by analyzing the crosslinking structure of the resulting vulcanizates prepared from untreated NR, deproteinized natural rubber (DPNR), and protein-free natural rubber (PFNR) by swelling methods and rubber-state NMR spectroscopy. The proteins present in NR were removed by three methods: deproteinization with enzyme, urea, or urea–acetone in the presence of sodium dodecyl sulfate. The amount of proteins present in NR, approximately 0.238 w/w%, was reduced to 0.000 w/w% by urea–acetone deproteinization, whereas it was reduced to approximately 0.003 and 0.019 w/w% by enzyme and urea deproteinizations, respectively. Hardness, swelling degree, and crosslinking structure depended on the amount of proteins. Changes in mechanical properties for the vulcanizates prepared from not only non-filler compounds but also carbon black–filled and silica-filled compounds were attributed to the amount of proteins.


2017 ◽  
Vol 744 ◽  
pp. 282-287
Author(s):  
Sarawut Prasertsri ◽  
Sansanee Srichan

This research aimed to develop the formulation of natural rubber filled with carbon black, silica and calcium carbonate for rubber calf nipple application. The reverse engineering was performed on the calf nipple product to analyze the rubber type and component by using Soxhlet extraction, thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) techniques. Furthermore, mechanical properties were examined to act as benchmark for the rubber compound design. The results showed that rubber component in the nipple product was natural rubber, whereas two filler types revealed as carbon black and calcium carbonate with 10 and 35 of the total weight. In addition, rubber nipple showed the hardness of 46±1 Shore A and tensile strength of 5.3±0.60 MPa. From the investigation of the properties of developed rubber compounds in this work, it was found that the mechanical properties depended on type and content of filler. The required mechanical properties of vulcanizates were achieved at 20 phr of carbon black (N330), 20 phr of silica and 120 phr of calcium carbonate.


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