FILLER NETWORKING OF A NANOGRAPHITE WITH A HIGH SHAPE ANISOTROPY AND SYNERGISM WITH CARBON BLACK IN POLY(1,4-CIS-ISOPRENE)–BASED NANOCOMPOSITES

2014 ◽  
Vol 87 (2) ◽  
pp. 197-218 ◽  
Author(s):  
Maurizio Galimberti ◽  
Vineet Kumar ◽  
Michele Coombs ◽  
Valeria Cipolletti ◽  
Silvia Agnelli ◽  
...  

ABSTRACT A nanoGraphite (nanoG) having a high surface area and a high shape anisotropy, defined as the ratio between the crystallite dimensions in a direction orthogonal and parallel to structural layers, was used to prepare nanocomposites based on poly(1,4-cis-isoprene) (IR), in the neat polymer matrix and in the presence of carbon black (CB). Tensile and dynamic-mechanical measurements showed that nanoG forms a filler network at a relatively low concentration in neat IR and a hybrid filler network at a lower nanoG concentration in the presence of CB. A synergistic effect between the two carbon allotropes was found: composites containing both fillers present initial modulus values much higher than those calculated through the simple addition of the initial moduli of the composites containing only CB or nanoG.

2021 ◽  
Vol 11 (23) ◽  
pp. 11410
Author(s):  
Gea Prioglio ◽  
Silvia Agnelli ◽  
Stefano Pandini ◽  
Maurizio Galimberti

Silica-based rubber composites have tremendous importance, as they allow the reduction in hysteresis in demanding dynamic-mechanical applications such as tire compounds and hence have a lower environmental impact. However, they also present drawbacks such as poor rheological behavior. In this work, an innovative silica-based hybrid filler system was developed, obtaining a rubber composite with an improved set of properties. A nanosized high surface area graphite (HSAG) was functionalized with 2-(2,5-dimethyl-1H-pyrrol-1-yl)propane-1,3-diol, serinol pyrrole (SP), through a simple process characterized by a high carbon efficiency. The HSAG-SP adduct, with about nine parts of SP per hundred parts of carbon filler, was used to form a hybrid filler system with silica. An elastomeric composite, with poly(styrene-co-butadiene) from anionic polymerization and poly(1,4-cis-isoprene) from Hevea brasiliensis was prepared with 50 parts of silica, which was replaced in a minor amount (15%) by either pristine HSAG or HSAG-SP. The best set of composite properties was obtained with HSAG-SP: the same dynamic rigidity and hysteresis and tensile properties of the silica-based material and appreciably better rheological properties, particularly in terms of flowability. This work paves the way for a new generation of silica-based composites, with improved properties, based on a hybrid filler system with a nanosized edge functionalized graphite.


2019 ◽  
Vol 9 (1) ◽  
pp. 186 ◽  
Author(s):  
Hai-Yan Hu ◽  
Ning Xie ◽  
Chen Wang ◽  
Fan Wu ◽  
Ming Pan ◽  
...  

The effects of carbon black specific surface area and morphology were investigated by characterizing four different carbon black additives and then evaluating the effect of adding them to the negative electrode of valve-regulated lead–acid batteries for electric bikes. Low-temperature performance, larger current discharge performance, charge acceptance, cycle life and water loss of the batteries with carbon black were studied. The results show that the addition of high-performance carbon black to the negative plate of lead–acid batteries has an important effect on the cycle performance at 100% depth-of-discharge conditions and the cycle life is 86.9% longer than that of the control batteries. The excellent performance of the batteries can be attributed to the high surface area carbon black effectively inhibiting the sulfation of the negative plate surface and improving the charge acceptance of the batteries.


2019 ◽  
Vol 48 (6) ◽  
pp. 523-532
Author(s):  
Muhammad Ali ◽  
Long Lin ◽  
Saira Faisal ◽  
Syed Rizwan Ali ◽  
Syed Imran Ali

Purpose This paper aims to analyse the let-down stability of the binder-free dispersion of non-printing ink grades of carbon black and to assess the screen-printability of the finished inks formulated thereof from these pigment dispersions. Design/methodology/approach Binder-free pigment dispersions that were prepared and optimised following a ladder series of experiments (reported in a separate study by the authors) were let-down with three different binders such that inks containing various amounts of a binder were prepared followed by a rheological characterisation immediately after formulation and after four weeks of storage. The screen printability of the inks that displayed considerable stability was assessed, so was the ink film integrity. Findings The pigment dispersions that were considered in the present study were generally found to be stable after let-down with different binders. This was indicated by the fact that the finished inks possessed a shear thinning viscosity profiles, after formulation and after storage, in most of the cases. Furthermore, the screen printability of the inks was also found to be good in terms of registration quality of a selected design. The structure of the ink film deposits on uncoated and binder-coated textile fabrics was also highly integrated and free from discontinuities. Originality/value Carbon blacks with very low volatile matter content and/or high surface area are generally not considered suitable for use in the formulation of printing inks. This is because of their generally poor dispersability and inability to form dispersions that remain stable over extended periods. This work, which is a part of a larger study by the authors, concerns with the stability of inks formulated from binder-free dispersions of such non-printing ink grades of carbon black. The major advantage of using such pigments in inks is that the required functionality is achieved at considerably low pigment loadings.


Carbon ◽  
2015 ◽  
Vol 81 ◽  
pp. 115-123 ◽  
Author(s):  
Suzanne S. Rich ◽  
Jonathan J. Burk ◽  
Chang Sun Kong ◽  
Cynthia D. Cooper ◽  
Daniel E. Morse ◽  
...  

1994 ◽  
Vol 9 (12) ◽  
pp. 3210-3222 ◽  
Author(s):  
Rex P. Hjelm ◽  
Wesley A. Wampler ◽  
Philip A. Seeger ◽  
Michel Gerspacher

This is a study of the form and structure of particles and particle aggregates of an experimental high surface area carbon black (HSA) using small-angle neutron scattering and the method of contrast variation. Contrast variation was effected by studying suspensions of the carbon black in cyclohexane containing different fractions of deuterocyclohexane. We find that the approximately 29 nm diameter USA particles are arranged as small, linear aggregates with an average aggregation number between 4 and 6. The structure averaged over the particle population is best represented by a prolate ellipsoid of revolution with semiaxes 14.5 and 76.4 nm. The surface of the aggregates appears smooth over length scales larger than 1 nm, which places an upper limit on the surface roughness observed by other methods. The internal structure of the aggregates is described by a shell-core model, with the shell density being consistent with a graphitic structure and the core being of lower density, more like amorphous carbon. Some fraction of the core volume (0.1 to 0.2) is taken up by voids that are not accessible to the solvent. An estimate of the shell thickness gives 1 to 2 nm along the ellipsoid minor axis and 6 to 10 nm along the major axis. The particles of the aggregate appear to be fused so that the less dense amorphous core is continuous through the inner parts of the aggregate. The information that can be obtained on the internal structure using contrast variation is limited by heterogeneity in the chemical composition of carbon black aggregates.


1974 ◽  
Vol 47 (2) ◽  
pp. 411-433 ◽  
Author(s):  
A. I. Medalia

Abstract The most highly reinforcing fillers, namely carbon blacks and silicas, consist of aggregates of quasi-spherical particles fused together. In the absence of direct experimental studies with single-particle carbon blacks or silicas of high surface area, we cannot be sure if aggregated structure is essential for good reinforcement, or whether aggregation and fusion just happen to accompany the formation of fine particles at practical concentrations. In any case, there is no doubt that the aggregate nature of the filler plays a major role in determining the properties of the rubber compound. Here I would like to review what we know about filler aggregates, especially of carbon black, and suggest some mechanisms for their effects on rubber; and also indicate where our knowledge seems inadequate at the present time.


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