Synthesis and dry-spinning fibers of sulfinyl-based poly(p-phenylene vinylene) (ppv) for semi-conductive textile applications

Abstract

Soluble, processable sulfinyl-based poly(p-phenylene vinylene) (PPV) precursors were synthesized, and the first sulfinyl-based PPV fibers were subsequently spun on a dry-spinning apparatus. 1-(Chloromethyl)-4-[(n-octylsulfinyl)methyl]benzene was synthesized in a 94% yield and polymerized via an analogous approach to the Gilch reaction. Post-polymerization, the sulfinyl group may be thermally eliminated from the backbone of the polymer to obtain conjugated PPV. ¹H NMR, ¹³C NMR, and FTIR confirmed that the polymer structure contained both sulfinyl- and pure PPV-based units. Thermogravimetric analysis indicated that up to 60% elimination of sulfinyl groups occurred during the polymerization reactions and before additional thermal treatment. Spinning dopes were prepared with 45 wt% polymer from 45.0 to 50.0 g of polymer in chloroform and had zero shear viscosities around 60 Pa s at 20 °C. Fibers were dry-spun with and without tension and various jet draw ratios from 0 to 151% to investigate changes in crystallinity, and X-ray diffraction patterns indicated enhanced orientation in the fibers compared to the unprocessed polymers. The fluorescent, conjugated polymer fibers possessed diameters less than 60 μm by SEM and remained soluble until thermal treatment at 150 °C.