Browsing by Subject "carbon black"
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Item Carbon Fillers for Actuation of Electroactive Thermoset Shape Memory Polyurethane Composites by Resistive Heating(2014-05-01) Yu, Ya-JenThe shape memory polymer (SMP) is one type of smart material with shape memory effect. SMP?s recovery can be actuated by external energy, such as heat. However, traditional direct heating limits potential applications of the SMP device. Thus, focusing on stimuli-responsive SMPs enables researchers to develop more versatile devices with SMP composites. The electroactive SMP composites incorporated with conductive fillers such as carbon black and carbon nanotubes allow shape recovery actuation by electrical resistive heating. Until now, most developments in electroactive SMPs are based on the use of a thermoplastic matrix doped with conductive fillers. Only limited reports have been made of thermoset polymers as the matrix used to synthesize an electroactive SMP composite. In this study, thermoset SMP composites with loading carbon black and carbon nanotube are made and characterized by evaluating thermomechanical behavior, measuring electrical resistivity and percolation threshold, coating with water-resistant membrane, and actuating the device with resistive heating. The electrical conductivity of thermoset SMP composites will be investigated so that a voltage-triggered or resistive-heat- triggered shape memory polymer for applications where a self-actuated polymer is necessary. The development of electroactive SMP composites makes this research advantageous for electrical resistive heating of device design in minimally invasive surgery application.Item Recovery and evaluation of the solid products produced by thermocatalytic decomposition of tire rubber compounds(Texas A&M University, 2007-04-25) Liang, LanA thermal catalytic decomposition process has been developed to recycle used tire rubber. This process enables the recovery of useful products, such as hydrocarbons and carbon blacks. During the catalytic decomposition process, the tire rubber is decomposed into smaller hydrocarbons, which are collected in the process. The solid reaction residue, which normally consists of carbon black, catalysts, other inorganic rubber compound components, and organic carbonaceous deposits, was subjected to a series of treatments with the intention to recover the valuable carbon black and catalyst. The process economics depend strongly on the commercial value of the recovered carbon black and the ability to recover and recycle the catalysts used in the process. Some of the important properties of the recovered carbon black product have been characterized and compared with that of commercial-grade carbon blacks. The composition of the recovered carbon black was analyzed by TGA and EDX, the structure and morphology were studied through transmission electron microscopy (TEM), and the specific surface area was measured by BET nitrogen adsorption. The recovered products possess qualities at least comparable to (or even better than) that of the commercial-grade carbon black N660. Methods for increasing the market value of this recovered carbon black product are discussed. Anhydrous aluminum chloride (AlCl3) was used as the primary catalyst in the process. A catalyst recovery method based on the AlCl3 sublimation and recondensation was studied and found to be non-feasible. It is believed that the catalyst forms an organometallic complex with the decomposed hydrocarbons, such that it becomes chemically bonded to the residue material and hence not removable by evaporation. A scheme for the further study of the catalyst recovery is suggested.