Ageing process nanocomposites

It is reasonable to link the mass loss with the observed changes in thermal stability and dielectric response, indeed some of this material that is evolved from the systems on aging is likely to be water and the reaction residues implicated as pro-degradants. However, the level of material lost the ongoing nature of the process and the clear link once again with a moist air environment points to an explanation other than simple passive loss of volatile residues from the nanocomposites. Cleary, an identification of this volatile material is desirable if the nature of the aging processes occurring within these polysiloxane nanocomposites is to be elucidated. 

The exposure of synthetic mbber nanocomposites during service against environmental influences like oxygen, temperature, static and dynamic mechanical load or UV-light effects aging processes. 

This chapter reports the results of the literature that concerns the photooxidation of polymer nanocomposites. The published studies concern various polymers (PP, epoxy, ethylene-propylene-diene monomer (EPDM), PS, and so on) and different nanofillers such as organomontmorillonite or layered double hydroxides (LDH) were investigated. It is worthy to note that a specific attention was given to the interactions with various kinds of stabilizers and their efficiency to protect the polymer. One of the main objectives was to understand the influence of the nanofiller on the oxidation mechanism of the polymer and on the ageing of the nanocomposite material. Depending on the types of nanocomposite that were studied, the influence of several parameters such as morphology, processing conditions, and nature of the nanofiller was examined. 

The Si-SiO core-shell nanocomposite is prepared by a sol-gel method in combination with a subsequent heat-treatment process. At first, molten Si with high purity was irradiated by laser and gasified under an Ar atmosphere, and the condensed Si nanoparticles were collected on a water-cooled wall. Then, the obtained Si nanoparticles were dipped into a stirred tetraethylorthosilane (TEOS) sol, followed by the processes of pH adjustment, aging, drying, and heat treatment. Finally, a core-shell structured Si-SiO nanocomposite was synthesized. Because the Si-hydroxyl groups in the TEOS sol possess high activity, the silica gel can be easily adsorbed onto the surface of the Si nanoparticles. The as-synthesized Si-SiO composites yield a core-shell structure. Besides, the crystalline structure of the obtained SiO shell is highly... 

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