No abstract

As part of a continuing effort to prepare novel thermally stable high-performance polymers, poly(arylene ether pyrimidine)s have been prepared with 4,6-bis(4-(trimethylsiloxy)phenyl)pyrimidine and a series of activated bis(aryl fluoride)s using a catalytic amount of cesium fluoride in diphenyl sulfone. These polymers exhibited good thermal stability in both air and helium atmospheres with 10% weight losses in the range 480−540 °C. Moderate to high inherent viscosities (ηinh:  0.40−0.92 dL/g) were recorded, and clear pale yellow flexible fingernail creasable films were solution cast from these samples. A polymer in this series containing a phenylphosphine oxide linkage exhibited good thin film tensile properties and resistance to oxygen plasma. Model reactions with 4,6-bis(4-fluorophenyl)pyrimidine and p-cresol along with studies of this compound's 19F NMR shift values indicated sufficient capacity of the pyrimidine ring to activate aryl fluorides toward polymerization with bis(phenol)s. The pyrimidine bis(aryl fluoride) monomer was used to prepare a series of polymers with selected bis(phenol)s by potassium carbonate-mediated aromatic nucleophilic substitution reactions. One example containing the fluorene moiety exhibited a high inherent viscosity (ηinh:  0.80 dL/g); however, only brittle films could be cast from polymers prepared by this approach.

The reactions of some ortho‐substituted anilines with various α,β‐acetylenic ketones were investigated as a route to 4‐alkyl‐, 4‐aryl‐, 4‐hydroxy‐, and 4‐amino‐3‐quinolyl ketones. The anilines examined were 2‐aminoacetophenone (1), 2‐aminobenzophenone (2), anthranilonitrile (3), methyl anthranilate (4), and ethyl anthranilate (5). The acetylenic ketones used were 1,4‐diphenyl‐2‐butyne‐1,4‐dione (6), 3‐butyn‐2‐one (7), 1,3‐diphenyl‐2‐propyn‐1‐one (8), and 4‐phenyl‐3‐butyn‐2‐one (9). The acetylenic ketones typically reacted with the anilines to give enamines; however, exceptions were found. Acetylene 6 reacts with 3 to give the enamine (13) along with a small amount of 2,3‐dibenzoyl‐4‐quinolamine (14). The reactions of 1 or 2 with 6 give the respective quinoline derivatives directly. Acetylene 8 reacts with 2 to give 3‐benzoyl‐2,4‐diphenylquinoline (22) directly, whereas no reaction occurs between 8 and 1 or 3. Acetylene 9 does not react with 1, 2, or 3. The enamines exist as the intramolecularly hydrogen bonded isomers and usually undergo cyclization with 5 molar equivalents of methanolic sodium methoxide to give quinoline derivatives. The 4‐quinolinols exist predominantly as the 4‐quinolinone tautomer.

SynopsisNovel poly(enonsu1fides) were prepared with inherent viscosities as high as 1.35 dL/g by nucleophilic addition of various aromatic dithiols to 1,l'-(1,3-or 1,4-phenylene)bis(3-phenyl-2-propyn-1-one) in m-cresol at 25-40°C. A tough clear yellow film with a tensile strength of 11,300 psi and a tensile modulus of 466,000 psi at 25°C was cast from a chloroform solution of the polymer prepared from 1,3-dithiobenzene and l,l'-(1,4-phenylene)bis(3-phenyl-2-propy-l-one). The poly(enonsu1fides) exhibited Tg's as high as 180°C and weight losses of approximately 10% at 331°C in air. The synthesis and characterization of several poly(enonsu1fides) are discussed.

SynopsisTwo types of polypyrazoles, unsubstituted and phenylated, were prepared by a novel synthetic route involving the cyclopolycondensation of aromatic dihydrazines and aromatic dipropynones. The polymers had inherent viscosities as high as 1.05 dL/g and were soluble in N, N-dimethylacetamide, chloroform (phenylated polypyrazoles only), and sulfuric acid. The polymers exhibited glass transition temperatures ranging from 202 to 266°C and polymer decomposition temperatures (10% weight loss) as measured by thermogravimetric analysis of 400-500°C in air and 465-512°C in nitrogen. The synthesis and characterization of several polypyrazoles are discussed.As part of an effort to prepare high performance/high temperature polymers for functional and structural applications, the reaction of aromatic dipropynones with various nucleophilic monomers is under investigation. The versatility of the dipropynone system in polymer forming reactions has been demonstrated by the preparation of high molecular weight poly(enamineketones) from aromatic and aliphatic d i a~n i n e s ,~,~ poly(enonesu1fides) from aromatic and aliphatic d i t h i~l s ,~?~ and now polypyrazoles from aromatic dihydrazines.Several researchers have reported the preparation of polypyrazoles by the condensation reaction of bis-&diketones with aromatic dihydra~ines.~-~ Korshak and co-workers5 first reported the preparation of aromatic polypyrazoles via this route. The polymers were soluble in m-cresol, N, N-dimethylformamide, and sulfuric acid. Schaefer' reported the preparation of a polypyrazole from 1,3-dihydrazinobenzene and 1,1,2,2-tetraacetylethane. Depending upon the reaction conditions, the polymer had an inherent viscosity as high as 2.0 dL/g and was only partially soluble in formic acid. Thermogravimetric analysis (TGA) revealed a temperature of 10% weight loss near 48OOC in air. Neuse' prepared metallocene polypyrazoles by the reaction of 1,l'-bis(diket0)ferrocenes with aromatic dihydrazines. These infusible, largely soluble polypyrazoles had inherent viscosities of 0.15 to 0.40 dL/g. The ferrocene containing polypyrazoles underwent incipient weight losses at ca. 400°C in argon with residual weights of 75-80% and 65-75%, respectively, a t 600 and 800°C. Imai and co-workers8 also prepared polypyrazoles by cyclopolycondensation of branched bis-p-diketones with aromatic dihydrazines.