2009 Volume 50 Issue 3 Pages 467-472
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 105 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.