In this thesis, rod-like mesoporous silica MCM-41 was synthesized by using tetraethylorthosilicate (TEOS) as silicon source,the cationic surfactant cetyltrimeth- ylamonium bromide (CTAB) as template and nonionic surfactant Os-25 as co-template. The effects of the content of surfactant, co-template,and ammonia, the stir speed and the temperature on the dispersion ability and morphology of mesoporous silica were investigated. The results indicated that the dispersion ability and morphology of mesoporous silica depended tightly on the parameters mentioned above. The addition of Os-25 with a proper amount could not only improve the dispersion ability, but also the orientation of pores. High quality MCM-41 with a large specific surface area and highly ordered, uniform hexagonal pores parallel to the axis of the silica rods was obtained under the optimized synthesis conditions.
Mesoporous silica filled Phenol formaldehyde resin（PF）composites (PF/MCM-41) were prepared by co-blending (CB), in-situ polymerization (ISP) and in-situ polymerization combined with co-blending (ISP-CB). The effects of MCM-41 on the heat-resistance of PF polymer were studied by use of IR, SEM, TG and XRD techniques. The results indicated that the heat resistance of the composites prepared by ISP and ISP-CB methods were improved remarkably.
The mechnism of improvement in heat-resistance of PF/MCM-41 composites was attributed to the infiltration of PF polymer into the pores of silica rods. The nanochannels of MCM-41 confined the movement of polymer chains inside them effectively. Meanwhile, the nano-scaled hole walls with lower thermal conductivity delayed the pyrolysis process of PF and restrained the release of the pyrolysate. As a result, the thermal stability of PF was improved obviously, especially during rapid heating of the composites.
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