Syntheses of oligophenylenevinylenes-polyisoprene diblock copolymers and their microphase separation

A series of functionalized oligophenylenevinylene (OPV) molecules have been synthesized via an orthogonal approach for the purpose of preparing dibloc k copolymers. The coupling reaction between the aldehyde-terminated OPVs an d a "living" polyisoprene (PI) species leads to the formation of OPV-PI dib lock copolymers. TEM results on thin films of four copolymers with the same OPV block but different lengths of the PI blocks clearly show nanophase se paration. Alternating strips of OPV- and PI-rich lamella domains were obser ved under TEM, confirmed by the SAXS experiments on bulk samples. Temperatu re-dependent SAXS studies also revealed an order-disorder transition at aro und 128 degrees C for copolymer 1, which is consistent with the TEM results .