Studies In Structure And Properties Of Inorganic-Organic Nanocomposites Particles

Organic-inorganic composites are of considerable interest and great importance because they give rise to a synergy between the inorganic particles and the polymer matrix in which they are dispersed. The most important remaining unsolved problem is the nature of the bonding between the filler particles and the polymer chains. The mechanical performance of composites depends to a great extent on the adhesion between the dispersed and the continuous phases. If the surface of the filler is incompatible with the polymer, then phase separation and agglomeration of filler particles occurs. The class of mesoporous M41S materials provide new opportunities for construction of nano-sized architecture. It can be expected that a polymer can either be introduced directly or produced through in situ polymerization of organic monomers inside the mesopores to form a nanocomposite structure based on MCM-48 structures. A potentially interesting and significant feature of the nanocomposite structure is that the polymer used to produce the nanocomposite structure inside the channels of MCM-48 can be altered according to the requirements of the final composite, being either the same as, or different from, the continuous polymer matrix, thereby providing the feasibility of finely tailoring the properties of the resulting composite.Firstly, A highly ordered mesoporous vinyl-functionalized MCM-48 material has been synthesized through both co-condensation and post-synthesis grafting methods. The co-condensation method gives samples with large pore sizes and higher thermal stabilities than the post-synthesis grafting method. A nanocomposite structure based on vinyl-functionalized MCM-48 and polystyrene (PS) or poly (vinyl acetate) (PVAc) was prepared through in-situ polymerization. Characterization by FT-IR, Raman, XRD and N2 adsorption-desorption techniques indicates that PS/vinyl-functionalized MCM-48 nanocomposites coupled at the nanometer level have been prepared by efficient polymerization of styrene monomers with the intrapore grafted vinyl groups. Addition of PS/vinyl functionalized MCM-48 and PVAc/vinyl functionalized MCM-48 nanocomposites to PS or PVAc gives rise to significant effects on the mechanical properties of the polymer. The mechanical performance of the resulting composites indicates that the properties of the intrapore polymer significantly modify the flexibility or rigidity of the material. The composite becomes harder and stronger when filled with the MCM-48-PS nanocomposite, in which the intrapore polymer is rigid. Addition of the MCM-48-PVAc nanocomposite, in which the intrapore polymer is more flexible, enhances the flexibility and toughness of the final compositeMorphology and other properties of PS polymerized in the MCM-48 channels have been studies.