|
Magnesium salt whisker, a new kind of inorganic functional material, has been gradually developed in recent years. At present, there are many reports about the application of magnesium salt whisker composites, but the action mechanism of magnesium salt whisker in plastic still needs to be discussed and studied. So, it was studied in this paper and the corresponding conclusions were drawn at last.Magnesium oxidesulfate whisker (MOS) and magnesium hydroxide whisker (MH), chose from magnesium salt whisker in this paper, were modified by stearate and copolymerization in the micro-latex of sodium dodecylsulphate. SEM, X Photoelectron Spectroscopy and FT-IR were used to analyze the morphology, elements, binding energy and functional groups of whisker surface, respectively, and modification effect was characterized by activation index. The results showed that, the whisker surface was rough and there was some bonding phenomenon on it. After modification the binding energy of Mg ,O elements was lower than the one before modification. The bond form between Mg, O elements had been changed and mating reaction may take place. The fact, that there were modifiers or copolymer layer on whisker surface after modification, was further confirmed by FT-IR analysis. On the basis of various testing and analysis, the models of surface structure were established firsrly. The activation index of whiskers after modification was higher than 84%.Add whiskers into polyethylene (PE), polypropylene (PP) and ABS matrix, respectively, prepare different kinds of composites. WDW-50E electronic universal testing machine and izod impact testing machine were used to test the mechanical properties of composites, SEM was analyzed the interfacial morphology and studied the action mechanism of whiskers in plastic matrix. The results showed that, there was not chemical bond between whiskers and matrix in composites. Under external force, the unmodified whisker was apt to be pulled out from matrix, the tensile strength and elongation at break of composites were lower. After modification by stearate, whiskers could be entangled with matrix, the mechanical performances were better, the intensity was also improved. Whisker deflection could be occurred under external force in copolymerization composite and the orientation of whiskers was random. The structure, which is made up of rigid whiskers and flexible copolymer, was capable of absorbing more energy, so the impact strength of composites was higher, the toughness was better.
|