Synthesis and characterization of poly(Arylene Ether Phosphine Oxide) dendrimer and hyperbranched polymers from $AB_2$ type monomers

Abstract

Two new $AB_2$ type monomers, bis(4-fluorophenyl)-4``-hydroxyphenyl phosphine oxide 4 and bis(4-hydroxyphenyl)-4``-fluorophenylphosphine oxide 7 were synthesized and polymerized to hyperbranched polymers through nucleophilic aromatic substitution reaction($S_nA_r$). The polymerization was carried out in N-methylpyrrolidone with $K_2CO_3$ as a base at 170℃. During the polymerization of the monomer 4 in NMP, precipitation was occurred after several hours and the obtained fluorophenyl-terminated poly(arylene ether phosphine oxide) was not soluble in any organic solvents. However, with appropriate amount of bifunctional core molecules such as 4-fluorophenyl sulfone, soluble hyperbranched polymers were obtained. Hydroxyphenyl-terminated hyperbranched polymer was prepared from the monomer 7. The polymer was soluble in aprotic polar solvents, although it has lower intrinsic viscosity than fluorophenyl-terminated hyperbranched polymers. The polymers were characterized by FT-IR and NMR spectroscopy and their thermal behaviors were studied with TGA and DSC. First generation of poly(arylene ether phosphine oxide) dendrimer was synthesized using bis(4-fluorophenyl)phenylphosphine oxide as a core moiety and bis(4-fluorophenyl)-4``-hydroxyphenyl phosphine as a dendron with potassium carbonate in NMP at 170℃. The dendrimer was characterized by $^1H$ NMR, $^{13}C$ NMR and $^{31}P$ NMR spectroscopy.