| The conductive rubber composite materials have a wide range of applications in militaryand civilian fields due to their unique merits, such as good conductivity, ductility, elasticity,airtightness, and corrosion resistance. The previous preparation of high-conductive rubberuses silver powder as conductive filler. However, the application of such rubber is greatlylimited due to the high price of silver. Currently, many researches are mainly focused on newtypes of conductive fillers to replace silver powder. Therefore, the fabrication of highlyconductive silver-based composite by electroless plating method was widely implemented andcarried out all over the world. Based upon the work done by former researchers, wesynthesized silver- and nickel-based composite particles using polystyrene （PS）microspheres、commercial glass fibers, and glass beads as the templates. Then, the conductiverubber composites were prepared using the above composite particles as conductive filler andsilicone rubber as matrix material, respectively. The parameters influencing the electrolessplating process and conductive rubber preparation process were systematically investigated,and main work and conclusions were summarized as following:（1） The polystyrene microspheres with the average size of 2.0μm were prepared by thedispersion polymerization technique with polyvinylpyrrolidone （PVP） as a dispersing agentand azobisisobutyronitrile （AIBN） as an initiator. The silver-based composite particles wereprepared through electroless plating method with self-made PS microspheres, commercialglass fibers, and glass beads as templates. Theρvvalues of the PS/Ag, glass fibers/Ag, andglass beads/Ag composite particles were 1.60×10-4·cm, 1.36×10-4·cm, and 3.14×10-4·cm, respectively. The conductive rubber composites were prepared with self-made glassfibers/Ag, glass beads/Ag composite particles as fillers. The conductivity and mechanical properties of such rubber were studied. The results showed that the electrical conductivityincreased but the mechanical properties decreased with the increase of conductive filleramount. The post vulcanization has a remarkable function to reduce theρvof conductiverubber, and the conductivity of the rubber can increase 1～2 orders of magnitude compared tothat treated by one segment vulcanization. Theρvvalues of the conductive rubbers, whichwere filled with glass fibers/Ag and glass beads/Ag composite particles with amount of 300phr, respectively, would decrease to 0.006 and 0.009·cm. It implied that such rubberpossessed excellent conductivity.（2） The nickel-based composite particles were prepared through electroless platingmethod with self-made PS microspheres, commercial glass fibers, glass beads as templates.The optimum preparation process of PS/Ni composite particles was described as following:the mass ratio of PS to NiCl2·6H2O was 4:7, NH3·H2O concentration of 30 mL·L-1,NiCl2·6H2O concentration of 0.21 mol·L-1, and PdCl2concentration of 0.006 mol·L-1. Theoptimum preparation process of glass fibers/Ni composite particles was as following: themass ratio of glass fibers to NiCl2·6H2O was 2:1, the mass ratio of NiCl2·6H2O toC6H5O7Na3·6H2O was 2:1, NH3·H2O concentration of 8 mL·L-1, and reaction temperature of75℃. Theρvof the PS/Ni, glass fibers/Ni composite particles were 0.03·cm and 0.0063·cm, respectively. Theρvof the glass beads/Ni composite particles prepared with theoptimum preparation process for glass fibers/Ni composite particles was 0.0091·cm .Theconductive rubber composites were prepared with self-made glass fibers/Ni, glass beads/Nicomposite particles as fillers. The effect of the one segment and post vulcanization on theρvof the conductive rubber were investigated. The results showed that the nickel-basedcomposite particles were seriously oxided and lead to the decreasedρv. So it was unease tocarry out post vulcanization. Theρvvalues of the conductive rubber filled with glass fibers/Ni,glass beads/Ni composite particles were 0.041·cm, and 0.08·cm, respectively, under theone segment vulcanization. |
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