scholarly journals Filler Dispersion in Hyperbranched Polyisobutylene

2004 ◽  
Vol 77 (2) ◽  
pp. 372-379 ◽  
Author(s):  
C. M. Roland ◽  
C. G. Robertson ◽  
L. Nikiel ◽  
J. E. Puskas

Abstract The microdispersion of carbon black filler in linear and hyperbranched polyisobutylene (PIB) was assessed from dynamic mechanical and volume resistivity measurements. While no significant differences were observed in the carbon black concentration necessary for formation of a filler network, in comparison to the linear polymer, the highly branched PIB was found to have substantially more carbon black agglomeration. This occurs despite its higher viscosity, due to the relative inaccessibility of large portions of the molecule, as a result of the profuse treelike branching. The consequence is more extensive interaggregate interaction, and thus a larger Payne effect and greater mechanical hysteresis.

2017 ◽  
Vol 90 (4) ◽  
pp. 611-620
Author(s):  
An Dong ◽  
Zhang Zhiyi ◽  
Jia Haixiang ◽  
Shou Jinquan ◽  
Zhang Huan ◽  
...  

ABSTRACT The influence of the structure and size of carbon black on the static mechanical and dynamic mechanical properties of filled natural rubber (NR) compounds is investigated in detail. A new process for the production of carbon black master batches with enhanced mechanical properties has been developed. The unit operations in the process are the preparation of carbon black slurry in the presence of a suitable surfactant, addition of the slurry to the fresh NR latex under stirring, coagulation of the mixture by the addition of acid, dewatering of the coagulum, and drying to obtain carbon black–incorporated NR. The competence of the new technique is established by comparing the characteristics of the carbon black–incorporated NR by the mill mixing process (control). The mechanical properties, including tensile strength, modulus, tear strength, and hardness, are superior for the vulcanization prepared by the latex-suspension coagulation techniques. The improvement shown by the vulcanization prepared by the latex-suspension coagulation techniques was attributed to the better filler dispersion evidenced from the scanning electron micrograph along with the attainment of a higher level of vulcanization.


2012 ◽  
Vol 217-219 ◽  
pp. 644-651
Author(s):  
Nai Xiu Ding ◽  
Li Li Wang ◽  
Mao Sheng Zhan ◽  
Liang Liu ◽  
Shuai Feng Xu

In this paper, Carbon black was activated using titanate-type coupling agent, and then filled into polypropylene to prepare conductive composites, whose alternating current (AC) electrical properties, including impendence Z, phase angel θ, dielectric constantε and dissipation factor tgδ that is a function of frequency and carbon black concentration were investigated by AC impedance spectroscopy. The percolation threshold of 5wt% carbon black concentration was obtained from the experimental result of volume resistivity for the conductive composites. It was found that the variation of AC electrical properties, which is a function of frequency, was dramatic and dependent on the filler concentration. It was also found that dependence of the real and the imaginary parts of impendence on frequency decreased with the increased concentration of carbon black, while the phase angle, dielectric constant and dissipation factor increased. The AC electrical properties were given based on the conductive network model and the corresponding equivalent circuit were concluded


2005 ◽  
Vol 78 (1) ◽  
pp. 76-83 ◽  
Author(s):  
J. Wang ◽  
G. R. Hamed ◽  
K. Umetsu ◽  
C. M. Roland

Abstract Double network elastomers were prepared by curing under strain previously-crosslinked natural rubber or styrene-butadiene copolymer. The rubbers were reinforced with carbon black, so that the conventional (singly-cured) materials exhibited a substantial Payne effect, reflecting agglomeration of the filler particles. This effect was much reduced in the double networks - the storage modulus varied more weakly with strain amplitude, and the mechanical hysteresis was substantially smaller. Comparable results were obtained for dynamic mechanical measurements employing different test geometries; that is, the effect is independent of the direction of the strain relative to the orientation of the double network. These results indicate that deformation during the imposition of a second network disrupts the carbon black agglomerates, and this deflocculated structure is stabilized by the second crosslinking. Thus, double network processing is a general means to lower the hysteresis of filled rubbers.


2020 ◽  
Vol 39 (1) ◽  
pp. 81-90
Author(s):  
An Zhao ◽  
Xuan-Yu Shi ◽  
Shi-Hao Sun ◽  
Hai-Mo Zhang ◽  
Min Zuo ◽  
...  

1995 ◽  
Vol 68 (2) ◽  
pp. 259-266 ◽  
Author(s):  
C. A. Sierra ◽  
C. Galán ◽  
J. M. Gómez Fatou ◽  
V. Ruíz Santa Quiteria

Abstract The interaction between rubber and carbon black in compounds for road tire treads has been analyzed by using mechanical and dynamical measurements in three cured compounds based on SBRs. The rubbers were prepared in solution by anionic polymerization, and coupled with tin compounds in which the carbon-tin bond at the end of the chain may correspond to styryl or butadienyl terminations. The interaction parameter, defined by the ratio of mechanical and dynamic terms, has been used for the first time for the evaluation of the compounds. The SBRs with tin-butadienyl bonds exhibit an improved interaction with the filler, with increasing tin content.


1996 ◽  
Vol 5 (5) ◽  
pp. 096369359600500
Author(s):  
L. Rejón ◽  
R. Flores ◽  
M. A. Ponce ◽  
V.M. Castaño

The electrical performance (current, I vs. voltage, V) of a novel polymer-based composite, modified with varying amounts of carbon black, was studied. Distinctive regimens of the I vs. V curves, before and after a critical carbon black concentration, were found and the feasible mechanisms for such behaviour are discussed.


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