Polymerization of aromatic nuclei. XXVI. Poly(p‐phenylene): Friedel–crafts alkylation, molecular weight, and propagation mechanism

Abstract

Poly(p‐phenylene) was alkylated with n‐propyl bromide, n‐propyl chloride, and isopropyl bromide in the presence of aluminum chloride. Apparently, the reactions involve dialkylation with n‐propyl halides and alternating mono‐ and dialkylation with isopropyl bromide. Alkylation with ethyl or n‐butyl bromide was unsuccessful. The dialkylated polymer was sufficiently soluble to allow molecular weight determination. Mechanistic aspects of alkylation and propagation are treated.

Electrochemical polymerization of p‐terphenyl in mixed electrolyte of boron trifluoride diethyl etherate and CH2Cl2

“…Furthermore, in this spectrum no strong absorptions at 840 and 860 cm −1 were detected, excluding trisubstituted and tetrasubstituted benzene respectively. These results agreed well with those reported for chemically or electrochemically synthesized poly( para ‐phenylene),29, 42, 43 and indicated that the principal structure of the PPP polymer was not cross‐linking. In conclusion, the PPP films obtained in this medium had a high regularity (linear structure).…”

Les complexes montmorillonite-Cu(III)-benzène: une contribution

“…Le spectre du r6sidu organique obtenu h l'issue du premier cycle pr6sente trois bandes d'absorption principales, h 810, 1005 et 1485 cm -1 (Fig. 4) correspondant aux bandes principales du poly (p-ph6nyl6ne) (Hummel & Scholl, 1968;Jones et al, 1981). Les bandes moins intenses,/a 705,770 cm -1, permettent de d6duire la pr6sence de noyaux monosubstitu6s en bout de cha~nes.…”

Tensile Behavior of a Substituted Poly(m‐,p‐phenylene) versus Its Parent Counterpart and Synthesis of Related Polyarylenes

“…The high rigidity of this polymer causes a melting point beyond its degradation temperature and low solubility in common organic solvents . The low solubility prevents reaching high molecular weights because the growing chains prematurely precipitate out of solution during synthesis and only insoluble oligomeric materials are obtained . In a first attempt to overcome this limitation, the monomers were decorated with solubilizing flexible alkyl side groups, which keep the growing polymer 1b in solution.…”