Thesis (M.Sc.)--Chulalongkorn University, 2008

The present research has studied the preparation of composite from natural rubber (NR) and various silica materials with high surface area and adsorption property. The silica materials include silica gel with various particle sizes and mesoporous silicas, i.e., MCM-41 and SBA-15. Influences of several parameters that affect dispersion of silica particles in NR and porosity of composite such as surface modification of silica materials to increase compatibility between NR and silica materials, preparation of NR composite, types, contents and sizes of silica materials, and calcination of mesoporous silicas were studied. The studies indicated that porosity of resulting NR composite increased with increasing content and decreasing size of silica material. Moreover, surface modification of silica materials hardly affects dispersion of silica particles in NR. However, it resulted in decreasing porosity of NR composite consisted functionalized silica materials. Further, slurry technique was appropriate preparation of NR composite with high porosity. With either increasing the silica content or decreasing the silica particles, porosity of the NR composites were increased. At equal loading of silica material, NR composite consisted of MCM-41 has highest porosity. From the study of vitamin C adsorption and desorption of NR composite, it indicated that adsorption and desorption quantity of NR composite filled with silica gel increased with increasing BET surface area and average pore volume of NR composite; while, one of composite filled with mesoporous silicas depended on size of interparticle voids on surface of composite.