Glass transition temperature silicone properties

Silicone rubber offers a set of unique properties to the market, which cannot be obtained by other elastomers. The Si-0 backbone provides excellent thermal stability and, with no unsaturation in the backbone, outstanding ozone and oxidative stability. The very low glass transition temperature, combined with the absence of low-temperature crystallization, puts silicones among the materials of choice for low-temperature performance. The fluoro-substituted versions provide solvent, fuel, and oil resistance along with the above-mentioned stability advantages inherent with the silicone backbone. 

As a coating offers increased anti-icing effectiveness and durability than fluorocarbon and silicone elastomers. These icephobic coats can reduce the accumulation of ice on products such as rooftops, aircraft, radomes, antennas, ships, and power-transmission lines. The weight of such accumulations of ice has led to aircraft crashes, fallen power lines, etc. The icephobic coats reduce the adhesive force between ice and a surface. Polyphosphazene elastomers possess these desired properties, in addition have low glass transition temperature (Tg), good environmental stability, curability, and moderate cost. 

Unfortunately, the incorporation of silicon into polymeric resists can alter the desirable materials characteristics. A decrease in the glass transition temperature often accompanies the inclusion of silicon into a resin, and most silicon substituents will drastically change the solubility properties of the parent polymer. For example, polymerization of propylpentamethyldisiloxyl methacrylate affords rubbery, low Tg polymers that are... 

To reduce the glass transition temperature of the rubber to improve the low-temperature properties of the ASA products. Especially preferred is ethyl-hexyl acrylate [59,60]. A further method is the incorporation of silicone rubber into the ASA particles [55,61-65]. 

The unique combination of properties, when coupled with water resistance and good low-temperature properties, arising from the relatively low glass transition temperature, have made silicones the material of choice for numerous coating applications and they have become an essential part of the paint industry s armoury for speciality coatings. 

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