Preparation and properties of polymers with biphenyl units in the chain: Syntheses of solvent‐soluble substituted polyphenylenes

Abstract

Benzidinetetrazonium chloride (BTC)–CuCl and BTC–FeCl2 complexes were thermally converted to benzene‐soluble poly‐4,4′‐biphenylene plus small amounts of insoluble material. The soluble fraction was more stable than the insoluble fraction when heated at 300–500°C, although the solubility decreased. BTC in water was converted to an insoluble material by addition of alkali or cuprous ammonia solution. The C/(H + Cl) ratio indicated the existence of three to five side groups for each twenty phenyl groups of the insoluble fraction, while that of the soluble fraction showed few such groups. The number increased to one or more side groups for each phenyl nucleus as both soluble and insoluble fractions were heated to 500°C. A thin film of soluble fraction deposited on a copper plate showed an electrical conductivity in the range 10−2–10−3 ohm−1 cm−1 at 25°C and an energy gap (ΔEg) of 0.2–0.3 eV. However, a compressed specimen of the same soluble fraction showed little conductivity. Solventsoluble samples of substituted poly‐4,4,‐biphenylene were prepared by the same procedure. These materials cracked on processing, and accurate conductivity measurements could not be made.

Preparation and properties of solvent‐soluble bridged polybiphenylenes and related copolymers

“…The product was refined in the same way as poly-(4,4'-biphenylene). 2 The yield was about 60%. The average molecular weight of this copolymer in benzene was in the range 12,000-16,300 (VPO measurement).…”

“…The termination of this copolymerization occurs not only by the recombination of radicals located at each end of the propagating molecules but also by the reaction of an end radical with CuClz released in the reaction system by the scission of the complex, the rate of which increases with a rise in reaction temperature. 2 The former reaction contributes to the increase in molecular weights of products and becomes predominant at reduced temperature in comparison with the latter reaction, which prevents the increase in molecular weights.…”

“…b R in +Ph-R-Ph-MMA j , . Viscosity curves of poly(4,4'-biphenylene) and bridged polybiphenylenes in DMF:(1 ) poly(4,4'-biphenylene), M, = 15,000;(2) polythiobiphenylene; (3) polymethylbiphenylene;( 4 ) polyiminobiphenylene.…”

Preparation of Water-Free PEDOT Dispersions in the Presence of Reactive Polyisoprene Stabilizers

“…For instance, processability of protonated (conducting) polyaniline was solved by introducing large counterions which decrease the strong interchain interactions . Another route which consists in the incorporation of side groups onto the rigid semiconducting backbone has been largely developed to substituted polythiophenes, polyphenylenes, or poly­(phenylenevinylene)­s, just to name a few. − For processability purposes, an elegant method consists in the preparation of semiconducting polymers under the form of colloidal dispersions, also named latexes, as most dispersant phases are water-based. − Pecher and Mecking recently reviewed strategies used to ease the processability of conducting polymers consisting in the preparation of semiconducting polymer latexes.…”