In order to generate the bending motion operated by pressure change in hydrogen gas, soft uni-morph composites were prepared, in which composites dispersed with not only driving particles of LaNi 5 hydrogen storage alloy with Pd-Al 2 O 3 catalyst powders to get high responsiveness, were piled up on a simple polyurethane sheet. Since the highest values of irreversible bending strain at the first hydrogenation (" 1) under 0.3 MPa H 2 gas and the maximum irreversible bending strain during hydrogenation cycles (" m) were remarkably obtained at the 35 vol% of LaNi 5 powders dispersed in polyurethane composites, the bending strain of reversible motion was detected from the first to the 8th hydrogenation (" r 1 and " r 8) under 0.2 MPa H 2 gas. The bending strain of reversible motion of polyurethane composites sheet is more than 2000 ppm, which was approximately equal to that of silicone rubber composites and is extremely larger than that (300 ppm) of ABS resin composites. Responsiveness (d"=dt) of cyclic motion of elastic deformed mover composites, which were constructed with 35 vol%LaNi 5 dispersed powder and matrix of polyurethane or silicone rubber, were more than 10 times higher than that of ABS composite.
In order to evaluate the influence of rapid homogeneous irradiation of electron beam with low potential (RHIEBL) on absorption phenomena of boiled water into nylon6, the absorbed mass of water in nylon6 has been measured. The RHIEBL decreases the saturated mass of water absorption in nylon6 and also decreases the initial absorption rate of water, as well as the absorption mass of water in nylon6 at each treatment time. Since the RHIEBL increases the initial reaction index from 1/2 to 2/3, RHIEBL changes the initial mode of water absorption, as well as decreases the absorbed mass of water. Based on the results of ESR and XPS, the RHIEBL forms dangling bonds and then decreases the electrical polarization of nylon6 molecules, resulting in a decrease of the mass of water absorption into nylon6.
The influence of dipping in hot salt solution on water absorption in nylon6 composites with dispersed aluminum powders was investigated. Dipping in hot salt solution (3 mass%NaCl in distilled water) for 10 5 s at 373 K increased the overweight of composite samples, whereas the addition of aluminum with dispersed powders (A1-addition) from zero to 40 vol%Al decreased the overweigh of the sample. Based on the experiment results and kinetic analysis, aluminum powder dispersion in nylon6 decreased the saturated overweigh of composites at infinite time. Both hot salt dipping and Al addition increased the reaction index (n). The Al addition apparently increased the n value of composites with less than 20 vol%Al in salt solution, as well as with less than 30 vol%Al in distilled water. The A1 addition apparently increased the kinetic constant (k) at less than 20 vol%Al in hot salt solution. However, the Al addition decreased the k value of composites at more than 30 vol%Al in hot salt dipping, as same as that of the composites dipped in hot distilled water. Compared with dipping in distilled water, dipping in hot salt solution apparently decreased the saturated overweigh and remarkably increased both n and k values of nylon6 composites with 10 and 20 vol%Al. Since Electron Probe Micro Analyzer (EPMA) analysis could not clearly detect sodium (Na) in the nylon6 matrix, the reaction rate of nylon6 composites dipped in hot salt solution was probably dominated by an interface control process.
In order to utilize for automobile body applications, poly-methyl methacrylic acid (acrylic resin, PMMA) composites dispersed by Al-powders was prepared by solution-casting, which could easily control the dispersion ratio. Although the Al addition gradually decreased the impact value, it radically enhanced the electrical conductivity at the critical volume fraction in polymer. The jump of electrical conductivity was observed at the critical volume fraction of the Al addition. Based on the percolation theory, the result was explained.
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