Center for Innovative Technology

Virginia Tech Intellectual Properties, Inc.

Virginia Polytechnic Institute and State University

Research, Incorporated

Ligochem, Inc.

Wolfgang G Glasser

Stephen S Kelley

Gamini Samaranayake

Rajesh K Jain

Willer De Oliveira

Li S Nieh

William Hugold Velander

Charles E Frazier

Kaliprasanna Dhara

James E Sealey, Ii

Jason G Todd

Jeffrey A Kaster

Swapan K Roy

Ackah Toffey

Markku A Sjostedt

Oscar Hsien-Hsiang Hsu

A chitosan starting material is combined with a dilute organic acid to produce a chitosonium ion complex. The chitosonium ion complex is then cast, sprayed, extruded, or otherwise processed to produce filaments, coatings, fibers, or the like. Heat is then used to convert the chitosonium ion complex into a N-(C.sub.1-30)acyl glucose amine polymer.

Chitin-based coatings

Chitosan support material is crosslinked using a heat-induced, amidification reaction in non-aqueous solvent. Crosslinking is achieved by the use of dicarboxylic acids which form amide bonds with chitosan. The type and degree of crosslinking can be controlled to tailor mechanical strength, solubility, and functionality, of the resulting chitosan support material. Quaternization and/or cyclodextrin-modification functionalization of the chitosan beads can also be effected in addition to the crosslinking to produce separation materials with great versatility and utility. The invention is applicable to chitosan support materials of various solids contents and geometrical shapes such as beads, fibers, films, and adhesive coatings.

Method of making ester-crosslinked chitosan support materials and

Method for magnetizing crosslinked chitosan support material involving the treatment of carboxyl group-containing, crosslinked chitosan gels with solutions of ferrous chloride followed by treatment with dilute aqueous alkali and then oxidation with molecular oxygen gas to produce highly-enriched magnetized chitosan particles, beads, films and/or coatings.

Method of making magnetic, crosslinked chitosan support materials and

A chitosan support material is made with crosslinking and installation of a spacer arm between the chitosan matrix and an epoxy terminal group at the distal end of the spacer arm. Among other things, the installed spacer arm endows the crosslinked chitosan beads with enhanced binding specificity during chromatographic separations.

Crosslinked hydrogel beads from chitosan

A method is described for the chemical modification of pre-shaped hydrogels in non-aqueous medium. The conditions permit the reaction of highly expanded, porous hydrogel particles, such as spherical beads, using pseudo homogeneous reaction conditions in the absence of water. The method involves a three step procedure in which the porous gels are solvent exchanged int a water-free solvent (step 1) with minimal change in gel dimension and porosity; followed by reaction under non-aqueous condition (step 2); and followed by solvent exchange into water (step 3). Many different types of reactions requiring non-aqueous conditions may be carried out using these conditions. The method has particularly been demonstrated for crosslinking fluorinating beads, and for esterifying beads in a reaction involving multifunctional free carboxylic acids in the presence of dicyclohexylcarbodiimide (DCC).

Chemical modification of shaped hydrogels in non-aqueous medium

The invention is directed to the formation of cellulose derivatives using homogenous phase reaction conditions. Cellulose is dissolved using DMAc/LiCl and a reagent system is added to promote the acylation of an appropriate acid anhydride or free carboxylic acid. One reagent system includes N,N-dicyclohexylcarbodiimide (DCC) and 4-pyrrolidinopyridine (PP). Another reagent system includes p-toluene sulfonyl chloride (TsCl) and pyridine (Py).

Cellulose derivatives with a low degree of substitution

A process for chemically modifying substantially pure xylose-rich oligosaccharides and polysaccharides in homogenous phase solution. The process may be advantageously utilized to produce biodegradable, thermoplastic, melt flowable, low shear resistant and low viscosity xylan derivatives.

Thermoplastic pentosan-rich polysaccharides from biomass

Improved cellulosic beads for use as supports in bioaffinity chromatography are produced by dissolution of cellulose in a chaotropic cellulose solvent, formation of the dissolved cellulose into droplets, and immersion of the droplets into a non-solvent capable of solvent interchange with the cellulose solvent to form generally spherical porous cellulose beads of narrow particle size distribution. The beads formed are preferably made with cellulose having a degree of polymerization between 100 and 200, and the resulting beads when saturated with water without drying contain between 1% and 7% cellulose by weight and have a particle size of at least about 0.3 mm. The beads can be activated by a suitable activation method, and specific bioaffinity ligands are bound to the active sites in the beads. The beads reacted ligands, the beads then used in bioaffinity chromatography to isolate specific bioaffinity molecules having molecular weights between 5,000 and 500,000 from complex solutions. The beads are particularly useful in bioaffinity chromatography of antibodies, therapeutic proteins, enzymes, and other high molecular weight proteins. The cellulose beads have similar properties to agarose beads used in the prior art for bioaffinity chromatography of high molecular weight proteins, but the cellulosic beads of the present invention have much greater mechanical strength and resist crushing under higher column flow rates without chemical cross linking are much cheaper to produce than prior art agarose and dextran beads.

Lignocellulosic and cellulosic beads for use in affinity and

Lignin sulfonates are converted into sulfonic acid esters by blocking free phenolic hydroxyl groups on the lignin sulfonates from reaction with a suitable protective group, subjecting the blocked lignin sulfonate in aqueous solution to ion exchange to produce the free sulfonic acid thereof, exchanging the aqueous solvent into a polar organic solvent, such as isopropanol, and reacting the sulfonic acid derivative in the polar organic solvent with a saturated or unsaturated aliphatic epoxide, preferably an alkylene oxide. The resulting sulfonic acid ester adduct may be isolated and purified from the reactants using solvent extraction. Lignin sulfonic acid ester adducts are produced that are soluble in a variety of organic solvents and insoluble in water.

Alkylene oxide esters of lignin sulfonic acid

A method of producing prepolymeric materials from lignin is disclosed. The method uses lignin which has been hydroxyalkyl modified, such that the lignin is substantially non-phenolic and solvent soluble and/or liquid. The modified lignin is reacted with materials which yield prepolymers which may be polymerized according to known methods to produce useful polymers.

Method of producing prepolymers from hydroxyalkyl lignin derivatives

Method of producing star-like polymers from lignin

Polycarboxy-oxyalkylene polyester-ether polyol intermediates useful in the production of polyurethane products and methods of making the intermediates and polyurethane products are described. The polyol intermediates are made from lignin by reacting lignin with maleic anhydride, substituted maleic anhydride, or mixtures thereof to form carboxylated lignin maleic anhydride copolymers. These copolymers are then reacted with an oxyalkylating medium with or without prior hydrolysis to form the polyol intermediates. These polyester-ether polyol intermediates are then reacted with an isocyanate medium having an isocyanate with at least 2 NC0 groups per molecule to produce polyurethane products with or without simultaneous foaming.

Growing community of inventors

Blacksburg, VA, United States of America

Wolfgang G Glasser