Chemical Modification of Polysiloxanes

Chemical modification of the basic structure of polysi-loxanes is normally performed to improve their RI. This involves introducing atoms/group of atoms into the chain backbone via two popular methods, njunely hydrosilylation cuid condensation. 

The formation of three-dimensional network will result if each silicone center bears more than a hydroxyl group. This polycondensation results in high molecular mass resin or elastomeric material. Since this is possibly performed at room temperature, it is known as room temperature vulcanization (RTV). In this case post-curing is performed to allow complete condensation reaction. Certainly the R group in the above reaction scheme bejus fimctioncd group which is able to affect increase in RI. 

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