苏州优锆新材料有限公司

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''>"Rubber Technology" >Li Qin
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'>Under the same preparation conditions with the same optimal addition amount of silica, >Enhance the mechanical properties exhibited by silicone rubber. After the optimal addition amount of
''>pure
''>fumed silica>is reinforced,>the tensile strength of silicone rubber is,>tear strength is>. Among the reinforcing effects of new silica
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''> on silica gel, the tensile strength and Compared with fumed silica, the tear strength is increased > and >, and the elongation at break is increased >. The reinforcing effect of
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''> is similar to that of fumed silica, but its elongation at break is increased>.
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'>Combined with the microscopic characterization of nanosilica,> analyze its enhancement mechanism.
''>Pure
''>Nano-silica prepared by the gas phase method can achieve enhanced effects by combining with the matrix because the hydroxyl groups on its surface can form hydrogen bonds with the oxygen atoms in the polymer chain. ,>However, due to the high surface energy of nanoparticles,>the agglomeration phenomenon is more serious>and the interface compatibility between inorganic particles and organic matrix is not good,>even if a silane coupling agent is added,>the enhancement effect is
''>Extremely
''>limited. Due to
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''>the in-situ modification of the surface of nano-silica particles,>the surface energy of the particles is greatly reduced,>matches the surface energy of silicone rubber,>and the two have good compatibility
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''>,>The degree of infiltration is large,>the interaction area between the matrix macromolecules and the nanoparticles is large,>enabling the remaining hydroxyl groups on the surface of the nanoparticles to better interact with the polymer chains The oxygen atoms on the surface interact in the form of hydrogen bonds, >offsetting the impact caused by the reduction in the number of hydroxyl groups >the fine dispersion and surface effects of the nanoparticles, >increasing the number of polymer chains adsorbed by the particles, >increasing the interaction with the silicone rubber Interaction,>When subjected to external force,>the entire system is uniformly stressed,>so it has a better reinforcing effect on silicone rubber
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''>.
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''>Nano>particle reinforced silicone rubber may have two reasons
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''>>Class< br/>''>
''>The coating of organic components on the surface of the nanoparticle chain makes it better dispersed in the polymer system and increases the formation of remaining hydroxyl groups and oxygen atoms on the polymer chain. The opportunities for hydrogen bonding enhance the effect
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''>>The particles and matrix have good compatibility and chain distribution, making the nanochains and polymer chains in the composite system able to Interlaced winding, > organic and inorganic networks intersect with each other, > the composite system has both the strength of inorganic materials and the toughness of polymer materials, > showing a stronger reinforcing effect.
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''>In addition, the new silica
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''>shows superior elongation at break compared to fumed silica. This is mainly because fumed silica > nanoparticles
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''> have a strong network structure of inorganic particles, > affecting the relative sliding movement of polymer chains, > limiting the fracture of the material. Elongation. The new silica
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''>has better compatibility with the matrix
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''>The addition of filler has a relatively smooth effect on the polymer chain. The effect of migration is not very great, and the better slip of the polymer chain increases the elongation at break of the system.
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'>The dispersion state of fumed silica> is obviously with the help of even The coupling agent is dispersed in silica gel, > the particles are not dispersed as primary particles, > and the dividing line between the agglomerate and the matrix is relatively clear, > it can be seen that the compatibility between the nanoparticles and the matrix is not good.
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''>Nano silica
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''>Good dispersion,
''>large
' '>Partially achieved primary particle level dispersion,>The compatibility between the particles and the matrix is good,>It is similar to the previous analysis results.
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''>Nano silica
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''>The dispersion in the matrix and the compatibility in the matrix are the best. The
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''>.
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''>The quality of compatibility can well explain the respective enhancement effects.
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''>New nano-silica
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''>can be well dispersed in In silicone rubber, it can have a very good reinforcing effect.
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''> Compared with the system adding coupling agent, the tensile strength, tear strength and elongation at break are greatly improved. The reinforcing effect of the
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''> system is equivalent to that of fumed silica, but the processing performance of the mixed rubber is greatly improved.
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''>Due to
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''>the chain structure of nano-silica forms an inorganic network and an organic polymer network that are intertwined with each other in the system. The crossed structure has a great effect and prevents the directional arrangement and crystallization of polymer chains at low temperatures, allowing the reinforced composite material to maintain good elasticity in low temperature environments.
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''>Nano silica
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''>particles have good interfacial compatibility with the matrix and can be present in the system. Relatively fine dispersion, even reaching the primary particle level dispersion, allows the enhancement effect of nanoparticles to be fully exerted.
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'>The morphological structure of nano-silica and the compatibility of inorganic particles and organic polymer matrix have a great influence on the reinforcing effect of silicone rubber.
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