Synthesis of poly(alkoxyphenylene vinylene-co-phenylene vinylene) type copolymers and electro-optic properties

Poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene-co-1,4-phenylene vinylene) (poly(MEHPV-co-PV)) and poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene-alt-1,4-phenylene vinylene) (poly(MEHPV-alt-PV)) were synthesized by the dehydrohalogenation using potassium t-butoxide and Honer–Emmons condensation, respectively. Single layer type light-emitting diode (LEDs) were fabricated utilizing both conjugated copolymers synthesized and MEH-PPV, PPV homopolymers. The λmax (EL) value of poly(MEHPV-co-PV)2 was closer to the PPV than that of poly(MEHPV-alt-PV), while the MEHPV content was higher (61 mol%) in the poly(MEHPV-co-PV)2 than in poly(MEHPV-alt-PV). This may be due to the block nature of MEHPV (or PV) repeat unit in the random copolymer, poly(MEHPV-co-PV)2.