Higher phenylenes, synthesis

Polymerization in a single-phase homogeneous solution in THF/water mixtures (2 1) has also been reported [235]. Such reactions allowed for the preparation of a poly (p-phenylene) with sulfonate ester and dodecyl side groups [Eq. (10)]. By comparison to the aforementioned biphasic polymerizations, the synthesis of polymers with higher degrees of polymerization was reported in the solution procedure. 

A degree of compatibility between polymers is introduced by IPN formation as two polymers are interlocked in a three-dimensional structure during synthesis. The phase domains are smaller in higher compatibility systems. Most of the early IPN studies were based on immiscible polymers and a small gain in phase mixing was observed. Frisch and coworkers prepared IPNs from PS and poly(2,6-dimethyl-l,4-phenylene oxide), which were miscible. Klempner prepared IPNs that contained opposite charges, and showed better miscibility than IPNs without charge. 

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