Four different reclaiming methods involving important reclaiming factors such as temperature, shear force, and atmosphere were used to reclaim ground tire rubber. The structure and performance of the reclaimed rubber were investigated. The reclaimed samples were all found to be mixtures of three parts: the sol part, a loosely crosslinked gel part, and low molecular substances. For a reclaimed product to have both good processability and mechanical properties, the ideal structure should be that the sol fraction and its molecular weight (Mn) are as high as possible. However, the high sol fraction and high Mn cannot be reached at the same time because of the nonselective scission of the main chain and crosslink bonds. Thus, for a reclaimed rubber to have high quality, the presence of some amount of gel fraction is essential. Our preliminary results showed that the recommended reclaiming method would be a process under oxygen‐free atmosphere, without severe shear force, and at relative low temperature. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

No abstract

Sulfur-cured butyl rubber was devulcanized completely in supercritical CO 2 by using diphenyl disulfide (DD) as a devulcanizing reagent. The optimum devulcanizing conditions were studied and the sol fraction of the reclaimed rubber obtained was up to 98.5%. The possible devulcanizing mechanism was investigated. Then, the sol component of reclaimed rubber was characterized by gel permeation chromatography, 1 H-NMR, and differential scanning calorimetry, and the reclaimed rubber was characterized by TGA. Because of the substitution of a large portion of allylic hydrogen by sulfurated functional groups during vulcanization, the signal of the olefinic proton shift. As a result of the numerous decreases in the active crosslinking sites and the remaining DD, reclaimed rubber could not be cured by sulfur. At last, the blends of virgin butyl rubber and different contents of reclaimed rubber were revulcanized and their mechanical properties investigated.

No abstract

As the key material for flexible electronics, free-standing supercapacitor electrodes have attracted great research interests in recent years. However, constructing the novel supercapacitor electrodes with excellent mechanical properties and high areal capacitance remains a challenge. This study demonstrates the fabrication of a highly flexible and mechanically robust supercapacitor electrode based on combination of aramid nanofibers (ANFs), multi-walled carbon nanotubes (MWCNTs), and polyaniline (PANI) in form of nanostructured composite film. The ANFs/MWCNTs/PANI film electrode obtained via vacuum-assisted layer-by-layer (VA-LBL) assembly technique achieves a tensile strength of 158.7 MPa and an areal specific capacitance of 497.3 mF cm−2 at a current density of 0.25 mA cm−2, showing an outstanding compatibility between high electrochemical performance and superior mechanical properties. In addition, the ANFs/MWCNTs/PANI film electrode exhibits an excellent cycle life with 89% capacitance retention after 3000 cycles. Synergistic effect from the strategic assembly of ANFs, MWCNTs and PANI in form of a single nanostructured platform makes this kind of free-standing electrode applicable for flexible and solid-state energy storage systems.