Hot Curing of the Polysiloxane

The polysiloxane from experiment b) is soluble in toluene. It can be converted by hot vulcanization into an insoluble silicone rubber. Using a small blender, 10 g of the polymer are kneaded with 10 g of quartz powder or 7.5 g of ground kieselguhr,and 0.6 g of dibenzoyl peroxide paste (50% in silicone oil).To work the additives into the silicone rubber without a mechanical blender is very tedious and difficult to achieve completely. 

The mixture is then heated for 10 min in the oven at 110 °C to bring about crosslinking. The solubilities of the mixture and the resulting silicone rubber are tested in toluene. 

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