Processes for increasing polymer inherent viscosity
AssigneesE. I. Du Pont de Nemours and Company, Magellan Systems International, LLC
InventorsDoetze Jakob Sikkema, David J. Rodini, Qinghong Fu Adkins, Steven R. Allen, Georg Valentin Martin, Ralf Demuth, Michael Schelhaas
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Abstract
Disclosed are processes for preparing polyareneazole polymers including contacting a molar excess of a free base in water with a terephthalic acid salt to form an aqueous mixture, adjusting the pH to precipitate a monomer complex, contacting the monomer complex with metal powder, and polymerizing the monomer complex. Polyareneazoles, filaments and yarns are also disclosed.
Claims20
A process for preparing a poly(1,4-(2,5-dihydroxy)phenylene-2,6-pyrido[2,3-d:5,6-d′]bisimidazole polymer comprising:
- contacting a molar excess of a 2,3,5,6-tetraamino pyridine free base in water with a 2,5-dihydroxy terephthalic acid salt to form an aqueous mixture,
- adjusting the pH of the aqueous mixture to within the range of from about 3 to about 5 to precipitate a monomer complex composed of 2,3,5,6-tetraamino pyridine and 2,5-dihydroxy terephthalic acid monomers,
- contacting, in polyphosphoric acid, the monomer complex with about 0.05 to about 0.9 weight percent metal powder based on the total weight of the monomers, and
- polymerizing the monomer complex in polyphosphoric acid to form the polymer.
A process for preparing a poly(1,4-(2,5-dihydroxy)phenylene-2,6-pyrido[2,3-d:5,6-d′]bisimidazole) polymer comprising:
- contacting 2,3,5,6-tetraamino pyridine free base in water with 2,5-dihydroxy terephthalic acid dipotassium salt to form an aqueous mixture,
- adjusting the pH of the aqueous mixture to within the range of from about 3 to about 5 to precipitate a monomer complex composed of 2,3,5,6-tetraamino pyridine and 2,5-dihydroxy terephthalic acid monomers,
- contacting, in polyphosphoric acid, the monomer complex with about 0.05 to about 0.9 weight percent metal powder based on the total weight of the monomers, and
- polymerizing the monomer complex in polyphosphoric acid to form the polymer.
Dependencies are inferred from the claim text.