Preparation and Properties of Hyperbranched Poly(ether ketones) with a Various Number of Phenylene Units

New AB 2 type monomers, with a various number of phenylene units, were prepared and converted to hyperbranched poly(ether ketones) by polymerization. Four kinds of AB 2 type monomers, 4-hydroxy-3‘,5‘-bis(4-fluorobenzoyl)-biphenyl, 1, 4-hydroxy-3‘‘,5‘‘-bis(4-fluorobenzoyl)- p -terphenyl, 2, 4-hydroxy-3‘‘‘,5‘‘‘-bis(4-fluorobenzoyl)- p -quarterphenyl, 3, and 4-hydroxy-3‘‘‘‘,5‘‘‘‘-bis(4-fluorobenzoyl)- p -quinquephenyl, 4, were synthesized in a stepwise manner starting from 3,5-bis(4-fluorobenzoyl)phenol, 5, repeating a series of conversions of the hydroxy group to the triflate, cross-coupling reaction of the triflate with ( p -methoxyphenyl)boronic acid, and cleavage of the methyl ether. Four kinds of hyperbranched poly(ether ketones) were prepared by the polymerization of the four AB 2 type monomers. Obtained hyperbranched poly(ether ketones) from 1 and 2 were soluble in various organic solvents including N -methyl-2-pyrrolidone, m -cresol, chloroform, and tetrahydrofuran, but those from 3 and 4 were insoluble in organic solvents. The thermal properties of these hyperbranched poly(ether ketones) depended on the number of the phenylene units. The values of the glass transition temperature increased with increasing number of the phenylene units, and only hyperbranched poly(ether ketone) from 5 showed crystalline character. The thermal properties of these hyperbranched poly(ether ketones) were compared with those of hyperbranched poly(ether ketones) having various numbers of phenylene units in the chain ends.