Hybrid silarylene-siloxane carboranylenesiloxane

Figure 61 The hybrid silarylene-siloxane/carboranylenesiloxane polymers, 99a-e.

In the case of aU of the developed hybrid silarylene-siloxane and carboranylenesiloxane polymers, an evaluation of the nature of different phases containing aromatic or carborane groups will be illuminating to understand what contribution does each distinct phase has on the elasticity and other material properties of the generated networks. Other in-depth mechanical studies are also in order to better evaluate the high temperature elasticity of the materials. 

The synthesis of block polymers of diacetylene-silarylene and diacetylene-carboranylenesiloxane polymers (99a-e) (Fig. 61) by the polycondensation reaction of 1,4-dilithiobutadiyne with l,4-bis(dimethylchlorosilyl) benzene and/or l,7-bis(tetramethylchlorodisiloxane)-m-carborane have been reported by Sundar and Keller.129 These polymers are a hybrid between the carboranylenesiloxane and silarylene-siloxane polymers and have high char yields (up to 85%) at 1000°C in N2 and in air, reflecting the thermal stabilizing effects of the carborane and aromatic units in the polymeric backbone. 

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