Polymers from 4‐(4‐hydroxyphenyl)phthalazin‐1‐one

Abstract

2‐(4′‐Hydroxyphenylbenzoyl)benzoic acid is readily available from phenolphthalein by reaction with hydroxylamine. On treatment with hydrazine, 4‐(4‐hydroxyphenyl)phthalazin‐1‐one is formed in high yield. Under conditions conventionally used for the synthesis of poly(aryl ether)s the phthalazinone reacts with 4,4‐difluorobenzophenone or 4,4′‐difluorodiphenyl sulfone to yield high molecular weight linear polymers which are thermooxidatively stable and have Tg's approaching 300°C. The phthalazinone NH groups behave like phenolic OH groups and the resulting polymers contain O‐C and N‐C linkages. Phenyl‐substituted phenolphthaleins have also been synthesized and converted to the corresponding phthalazinone polymers.

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.…”

Poly(arylene ether)s and poly(arylene thioether)s containing the 1,2-dihydro-4-phenyl(2H)- phthalazinone moiety

“…The full characterization of this high molecular weight polymers were readily synmonomer has been published. 7,8 The NMR proton signals of the O{H and N{H groups for 2 are at d Å 9.81 ppm and 12.74 ppm, respectively. 8 By reacting with one equivalent of potassium hydroxide in ice-chilled methanol solution, the hydroxy group in 2 was selectively transformed into the N,N-dimethylthiocarbamate group to give 3.…”

“…6,7 This unexpected property has been rationalized by its rigidity, which can be seen in molecular models. Another very interesting diketone monomer developed in this laboratory, 1,2-bis(4-fluorobenzoyl) -3,4,5,6-tetraphenyl (5a), also gave polymers with…”

“…A potentially inexpensive and easily prepared heterocyclic monomer, 1,2-dihydro-4-(4-hydroxyphenyl)(2H)phthalazin-1-one (2), was synthesized several years ago in this laboratory. 6,7 This monomer forms high-temperature polymers with excellent thermal and hydrolytic stability by polyScheme 1. Synthesis of 1,2-dihydro-4-(4-hydroxymerization with activated dihalo compounds.…”

Importance of chromophore environment on the near-infrared absorption of polymeric waveguides

“…10 Figure 7 shows the absorption spectra of chromophore 5 in these matrices. The absorption coefficients are normalized to a 10-wt.…”