| Polysiloxane is being used extensively in many fields for its good physical and chemical performance, such as high/low temperature change resistant,radiation resistance, oxidation resistance, high permeation of gas, weatherability, hydrophobicity and physiologically inert. Organic groups (such as epoxy, amino group, carboxyl) can give the polysiloxane appended function and new valuable properties. As one of the organically modified polysiloxanes, amio-modified polyorganosiloxane has been used extensively. And it provides higher surface activity and reactivity, by putting amino group into the side chain or the terminal of the chain. Silicone rubber is one of the products for the application of polysiloxane. Because of the low damping properties of silicone rubber, chemical and physical modified polysiloxanes are usually used to improve the tanδso as to expand the application of silicone rubber.In this thesis, epoxy grafted amino-side chain-modified polysiloxane is achieved, and the content of the epoxy modified amino side chain is controlled by the amino value of the amino-polysiloxane. The relationship between the mechanical damping properties of the epoxy modified silicone rubber and the content,structure of epoxy side chan, the molecular weight of epoxy modified polysiloxane is studied.By block copolymerization and degradation of Si-O-Si to form Si-OH, hydroxyl-terminated polyaminomethylsiloxane has been synthesized. The best synthetic conditions are:110℃(polymerization temperature),0.4‰(content of catalyst),3h(reaction time under 0.06MPa),0.01g/ml(degradation water, over 0.3ml). By controlling the amount of degradation water and the ratio of raw materials, 1.55%,5%,11%,13.86%,18.46% of the content of Si(CH3)(C3H6NHC2H4NH)-O and different molecular weight of hydroxyl terminated polyaminomethylsiloxane have been obtained. And when the content is over 11%, it is soluble in anhydrous methanol.The reaction extent and phenomena of 5 different structure of single-functional epoxy(660,692,AGE,NC-513,GMA) and the above different content of amino vale and molecular weight of polyaminomethylsiloxane are studied. And found that 660,692, NC-513, AGE, GMA grafting reaction under solvent system left to mild cross-linked polymer gel, while In the absence of the solvent, the grafted reaction between 660,692, AGE and polyaminomethylsiloxane resulted as higher viscosity of polymer but no gel;however, NC-513 gel and GMA solid elastic polymer.Under the curing process of 15% HB-615SiO2,10% crosslinking agent,2% of the catalyst, the relationship between the mechanical properties of 660,692, AGE Graft cured polysiloxane of silicone rubber and molecular weight of the polymer, content and structure of the grafted side chain has been studied. The suitable molecular weight of the polysiloxane can improve the mechanical properties of the epoxy-modified silicone rubber. The mechanical strength decreased with the rising content of the epoxy-modified side chain.660,692 modified silicone rubber has better mechanical properties, with tensile strength, elongation at break, tear strength respectively are:0.82MPa,252.7%,1.99KN/m;1.43MPa,317.6%,3.58KN/m. With regard to the damping properties,660,692, AGE modified silicone rubber have lower Tg, and the damping properties of silicone rubber have been improved. The damping value can be reached respectively:0.6553,0.5155 and 0.2608. And the damping properties increased with the rising content of the epoxy-modified side chain.Field emission scanning electron microscopy is used to observe the fracture surface of the epoxy modified silicone rubber. And the uniformly distributed nano-filled structure of the silica filler particles in the silicone rubber has been found. The C-OH of epoxy modified polysiloxane increases the compatibility between silica and the polysiloxane. Epoxy modified silicone rubber with excellent damping properties has been obtained.
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