Patent number: 9650742

Abstract: A process for making a hydrogel forming material from a kraft or sulfite pulping process cellulosic pulp slurry by extracting hemicellulose heteropolymers from the cellulosic pulp slurry as a hemicaustic extract by treating the cellulosic pulp slurry with a cold caustic solution, then isolating the hemicaustic extract and preparing a mixture of the hemicellulose extract and a derivatizing agent comprised of a monofunctional etherifying agent and/or a polyfunctional organic cross-linking agent, and reacting the mixture to produce the hydrogel forming material. A polyvalent metal cross-linking agent can optionally be reacted with the hydrogel forming material to enhance its gel strength.

Date of Patent: May 16, 2017

Inventors: Othman A. Hamed, Romuald S. Krzywanski


Patent number: 9382337

Abstract: A process for making a hydrogel forming material from an unbleached cellulose pulp comprised of isolating pulp fines from the cellulose pulp by screening and/or dissolved air filtration, reacting the isolated pulp fines with alkaline hydroxide to form an alkali cellulose composition, preparing a heterogeneous mixture of the alkali cellulose composition and an etherifying agent, and optionally organic cross-linking agent, and reacting the components of the mixture to produce a hydrogel forming material. A polyvalent metal cross-linking agent can optionally be reacted with the hydrogel forming material to enhance its gel strength.

Date of Patent: July 5, 2016

Inventors: Othman A. Hamed, Romuald S. Krzywanski