Synthesis of All-Aromatic Phthalazinone-Containing Polymers by a Novel N−C Coupling Reaction

Abstract

High molecular weight poly(phthalazinone)s with high glass transition temperatures were prepared by a novel N−C coupling reaction. New bis(phthalazinone) monomers (5a−f), such as 7,7‘-oxobis[4-phenylphthalazin-1(2H)-one] (5c), were synthesized from the corresponding bis(phthalic anhydride)s (3a−f) in two steps. Other types of bis(phthalazinone) monomers (8, 9) were synthesized from phthalic anhydride and diphenyl sulfide or diphenyl ether. AB-type phthalazinone monomers (11a, 12−14) were also synthesized from phthalic anhydride. Poly(phthalazinone)s, having inherent viscosities of 0.3−0.4 dL/g, were prepared by the reaction of the bis(phthalazinone) monomers with an activated aryl halide such as bis(4-fluorophenyl) sulfone (22) in a dipolar aprotic solvent in the presence of potassium carbonate. AB-type phthalazinone monomers do not form high molecular weight polymers because of premature precipitation during the polymerization reaction. One of the AB-type phthalazinone monomers, 4-[4-((4-fluorophenyl)sulfonyl)phenyl]phthalazin-1(2H)-one, was successfully copolymerized with 4,4‘-biphenol and bis(4-fluorophenyl) sulfone to form high molecular weight polymers. The copolymers showed higher glass transition temperatures (T gs) as the phthalazinone ratio increased. All phthalazinone homopolymers except the Bisphenol A phthalazinone polymers show T gs around 300 °C by differential scanning calorimetry. The decomposition temperatures for 5% weight losses in air and in nitrogen measured by thermogravimetric analysis are in the range of 480−530 °C. Polymers from the Bisphenol A phthalazinone monomer are soluble in chlorinated solvents such as chloroform. Other polymers are soluble in dipolar aprotic solvents such as N-methyl-2-pyrrolidinone. The soluble polymers can be cast into flexible films from solution.

Dynamic Mechanical Properties of PPESK/Silica Hybrid Materials

“…Novel poly(phthalazinone ether sulfone ketone) (PPESK) copolymers containing different ratios of diphenylsulfone and diphenylketone units were previously synthesized [2][3][4] from 1,2-dihydro-4-(4-hydroxy-phenyl)-phthalazin-1-one [5,6] . There are plans to commercialize these condensation polymers, derived from this phthalazinone monomer that is readily prepared from the commodity chemicals phenol, phthalic anhydride and hydrazine.…”

Synthesis and properties of novel H-bonded composite membranes from sulfonated poly(phthalazinone ether)s for PEMFC

“…Phthalazinone-based polymers are well-explored type of high performance heterocyclic polymers with excellent thermal, mechanical and oxidative properties [13][14][15]. It is reasonable to investigate the potential usage of these polymers in PEMFC after suitable sulfonation modification to entitle their ionic conductivity.…”

NMR studies on 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)‐4‐phenyl]‐(2H)phthalazin‐1‐one

“…The assignments of C-1 (158.2 ppm), C-4a (128.6 ppm) and C-8a (128.3 ppm) were identified from the cross peaks of 3 …”

“…1,2 Yoshida and Hay first reported that phthalazinone compounds could be used as bisphenol monomers to prepare highperformance poly(arylene ether)s. 3 We have previously synthesized phthalazinone-based diamines and polymers. 4 -6 To our surprise, the aromatic polyamides and polyimides derived from the phthalazinone-based diamines have good solubility and display excellent thermal properties.…”