Syringe-Type Apparatus for Quantitative Hydrogenation at Constant Pressures Above 1 Atmosphere

Gould, Clark.; Drake, Herbert

doi:10.1021/ac60056a030

Cited by 5 publications

References 14 publications

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Polymerization by oxidative coupling. III. Mechanistic type in the copper–amine catalyzed polymerization of 2,6‐dimethylphenol

Endres

Kwiatek

1962

J. Polym. Sci.

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Since the oxidative polymerization of 2,6‐disubstituted phenols through copper–amine catalysis represents a novel polymerization reaction, particular interest attaches to the question of mechanistic type, i.e., stepwise or chain reaction. In the oxidation of 2,6‐dimethylphenol in the presence of copper(I) chloride in pyridine solvent, the dependence of the degree of polymerization on the extent of reaction corresponds to a stepwise reaction of the type where polymer growth occurs through reaction of polymer molecules with each other, as well as with the monomer. The reaction is thus formally analogous to a bifunctional polycondensation. The isolation of low intermediate polymers from the reaction mixture and the facile polymerization of these intermediates or the synthetic dimer or trimer in the absence of monomer supports this view. Comparison of the infrared spectra of the intermediates with the model compounds supports the poly(1,4‐phenylene ether) structure, and the absorbance in the hydroxyl region indicates one hydroxyl group per molecule. Partially oxidized reaction mixtures also yielded small amounts of the compound 4,4′‐dihydroxy‐3,5,3′,5′‐tetramethyldiphenyl, the precursor of the tetramethyldiphenoquinone formed as by‐product on complete oxidation. A study of the rates of oxygen absorption in the polymerization of the monomer, dimer, trimer, and intermediate polymer showed little dependence on the degree of polymerization from the dimer upward.

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