High-efficiency synthesis of a naphthalene-diimide-based conjugated polymer using continuous flow technology for organic field-effect transistors

A conjugated polymer based on naphthalene-diimide and dithiophene units was synthesized by continuous flow synthesis. Due to the large specific surface area and excellent heat transfer, the polymerization was completed within similar to 35 min at 110 degrees C. Compared to flask synthesis, the continuous flow technology exhibited a high synthesis efficiency and significant reduction in reaction times. The polymer using flow synthesis exhibited higher molecular weight (17.28/35.27 vs. 4.86/13.21 kg mol(-1)), lower polydispersity indexes (2.0 vs. 2.7), and a more ordered crystalline structure. Consequently, much higher electron mobilities (0.74 vs. 0.11 cm(2) V-1 s(-1)) with I-on/I-off ratios of 10(6) were obtained for the polymer using flow synthesis. This study demonstrates that continuous flow synthesis will be promising in the preparation of conjugated polymers with high efficiency.