Abstract: Disclosed are methods of producing modified microcrystalline chitosan. Chitosan in aqueous solution is degraded enzymatically, hydrolytically or oxidatively. The chitosan solution is then alkalized with agitation using aqueous hydroxides and/or their salts to attain a pH not lower than 7.0. The precipitated modified microcrystalline chitosan is highly pure and may be concentrated and dried according to known methods. Methods according to the invention also include methods by which an aqueous solution of chitosan is first alkalized using hydroxides and/or their salts to a pH not lower than 7.0. Then the precipitated microcrystalline chitosan is subjected to enzymatic or oxidative degradation to achieve a desired average molecular weight and polydispersity. The product is highly pure and may be concentrated and dried according to known methods.

Abstract: Disclosed are methods of producing modified microcrystalline chitosan. Chitosan in aqueous solution is degraded enzymatically, hydrolytically or oxidatively. The chitosan solution is then alkalized with agitation using aqueous hydroxides and/or their salts to attain a pH not lower than 7.0. The precipitated modified microcrystalline chitosan is highly pure and may be concentrated and dried according to known methods. Methods according to the invention also include methods by which an aqueous solution of chitosan is first alkalized using hydroxides and/or their salts to a pH not lower than 7.0. Then the precipitated microcrystalline chitosan is subjected to enzymatic or oxidative degradation to achieve a desired average molecular weight and polydispersity. The product is highly pure and may be concentrated and dried according to known methods.

Abstract: Methods for deproteinizing chitosan are provided. Proteins are dissolved in aqueous solution under intensive agitation. Precipitated agglomerated microcrystalline product Is subject to aqueous acidic or basic salt solution, from which dissolved proteins can be removed. Residual product is deproteinized chitosan.

Abstract: Chitosan-calcium complexes of calcium (II) ions with a gel of a chitosan salt, containing not less than 0.5 wt % of the polymer with an average molecular weight not less than 10 kD, a polydispersity degree not lower than 2.0 and a deacetylation degree at least 65%. The complex is characterized by pH not higher than 6.9 and a calcium Ca (II) ions content not less than 0.1 wt % on chitosan. Methods to prepare chitosan-calcium complexes use a gel of a chitosan salt, containing not less than 0.5 wt % of the polymer. Calcium salts are introduced in the amount of at least 0.1 wt % Ca (II) on chitosan weight. The mixture is next homogenized and reacted at 10° C. during a time not shorter than 1 minute. Methods of producing a gel of chitosan salts involves subjecting a chitosan with the concentration of at least 0.5 wt % in an aqueous acidic solution to a controlled enzymatic, hydrolytic or oxidative degradation.

Abstract: Disclosed are methods of producing modified microcrystalline chitosan. Chitosan in aqueous solution is degraded enzymatically, hydrolytically or oxidatively. The chitosan solution is then alkalized with agitation using aqueous hydroxides and/or their salts to attain a pH not lower than 7.0. The precipitated modified microcrystalline chitosan is highly pure and may be concentrated and dried according to known methods. Methods according to the invention also include methods by which an aqueous solution of chitosan is first alkalized using hydroxides and/or their salts to a pH not lower than 7.0. Then the precipitated microcrystalline chitosan is subjected to enzymatic or oxidative degradation to achieve a desired average molecular weight and polydispersity. The product is highly pure and may be concentrated and dried according to known methods.

Abstract: Process for producing fibres, film, casings and other products from modified soluble cellulose wherein the initial cellulose is hydrothermally treated at a temperature in the 100-200° C. range, under a pressure in the range from about 0.1 to 1.5 Mpa in a water/cellulose ration on a weight basis of at least 1:1 in the presence of a complex activator composed of Lewis acids and/or bases and/or their salts in an amount of at least 0.0001% by weight calculated on cellulose. The obtained modified cellulose pulp after, a possible purification, is in a dry or never dried condition, dissolved in an aqueous solution of alkali metal hydroxides. The dissolving is carried out at a temperature not lower than 0° C. for 1-120 minutes to obtain a homogenous spinning solution with the cellulose concentration at least 1% by weight. The alkaline cellulose solution is filtered, deaerated and coagulated by contacting it with water or aqueous acidic solutions.

Abstract: Disclosed are bioagent compositions for plant care which can be used for treatment of plants and seeds. Such treatment serves to inhibit the activity of plant pathogens against the treated plants, stimulate natural plant immunity against such pathogens and provides plant growth biostimulation. The compositions comprise a chitosan polymer which can either be in the form of particles of microcrystalline chitosan which are in a composition of pH greater than 6.9, or in the form of a chitosan salt gel which are in a composition of pH of from 5.0 to 6.9. In either form, the chitosan polymer has specified molecular weight, polydispersity degree and degree of deacetylation characteristics. Preferably the chitosan polymer has a bimodal molecular weight distribution and contains a fraction of water-soluble oligoaminocarbohydrates.

Abstract: A polypropylene composition and modified fibers thereof, includes polypropylene and an elastomer. The elastomer has a melting temperature of, at least, 80° C., preferably 100-180° C., a melt flow index in the range of 1-60 g/10-min., and a density within the range of 0.85-0.95 g/cm3. The elastomer is a branched copolymer of an ethylene copolymer, a polyolefin copolymer or a combination thereof, with ethylene, higher alkene groups, or both ethylene and higher alkene groups in the main chain of the branched copolymer, and with a weight proportion of polypropylene to elastomer being in the range of from 99.9:0.1 to 0.1:99.9. A method for producing the polypropylene composition and modified fibers thereof is also disclosed.

Abstract: A substance for reduction of absorption of lipids and for reduction of serum cholesterol content in mammals comprising microcrystalline chitosan. The microcrystalline chitosan can be administered orally in food products or in dose units containing a predetermined amount of microcrystalline chitosan. The microcrystalline chitosan has an average particle size not higher than 100 &mgr;m.

Abstract: Disclosed is a process for producing particles of the modified carbohydrate polymer chitosan. Such chitosan particles are “activated” as a consequence of the specific steps used in the process. The process involves precipitation of dissolved chitosan from an acid solution thereof by the step-wise addition of neutralizing agent to the solution. A partial neutralization is carried out under shear agitation to form a continuous gel phase having a pH within the range of 5.0 to 6.9. This partially neutralized chitosan gel phase is then further subjected to shear agitation for at least 10 seconds to homogenize the gel phase. The homogenized gel phase is then further neutralized under shear agitation to a pH of above 6.9 to form a gel-like suspension of discrete chitosan particles. Chitosan particles in this form are useful in a number of contexts including, in particular, in the area of plant care.

Abstract: Process for producing cellulosic moldings such as fibers, foils, casings and beads from cellulose, wherein (a) the initial cellulose is hydrothermally treated with water in a water/cellulose ratio on a weight basis of at least 1 at a temperature in the range from about 100.degree. to about 200.degree. C. and under a pressure in the range from 0.1 to about 1.5 MPa; (b) the treated cellulose is dissolved in an aqueous solution of alkali hydroxide at a temperature of at least 0.degree. C. to form a homogenous cellulose solution containing from about 5% to about 10% by weight cellulose and at maximum 10% by weight alkali hydroxide, and (c) the alkaline cellulose solution is formed and coagulated by contacting it with an aqueous solution containing 1 to about 30% by weight of an acid. This fully ecological process avoids handling of toxic products or by-products and uses aqueous solvents instead of expensive organic solvents. The cellulose solution is stable for at least 48 hours.

Abstract: A method for the manufacture of cellulose carbamate, whereby cellulose pulp is preliminarily activated by alkaline, hydrothermal and/or enzymatic treatment, then the activated cellulose pulp is mixed with aqueous urea solution, the water in the solution replaced with an organic reaction carrier, and thereafter the cellulose is reacted with urea in the liquid phase to yield cellulose carbamate, which is separated from the liquid medium and washed. The method results in uniform substitution and distribution of carbamate groups and in cellulose chain, which leads to good solubility of the cellulose carbamate in aqueous alkali solution as well as excellent spinnability for producing fibers, films, and other products.

Abstract: Modified viscose fibres comprise regenerated cellulose and contain in their structure microcrystalline chitosan bound mainly by hydrogen bonds with the regenerated cellulose of viscose fibres. To improve the properties of the fibres the modified fibres contain as a third component a water-soluble and/or alkali-soluble natural polymer or a derivative thereof of polysaccharide origin containing groups bound by hydrogen and/or ionic bonds with the microcrystalline chitosan. Examples of such polymers are alginic acid, sodium and potassium alginate and sodium carboxymethycellulose.

Abstract: Microcrystalline chitosan is used in seed encrusting in the form of liquid dispersion containing 0.0001-10 wt. % of polymer characterized by average molecular weight not lower than 1000, water retention value ranging from 200 to 5000%, deacetylation degree not lower than 35%, particle size in the range of 0.1-100 .mu.m and energy of hydrogen bonds in a form of film of 10-25 kJ/mol. The liquid dispersion is introduced by spraying or mixing with a content of polymer not lower than 0.01 wt. %, whereafter the excess of solvent is removed and polymer film covering the seed is formed.