Instytut Wlokien Chemicznych

The Procter Gamble Company

Abbott Laboratories Corporation

Zimmer Aktiengesellschaft

Lurgi Zimmer Aktiengesellschaft

Institute of Chemical Fibres

Alojzy Urbanowski

Henryk Struszczyk

Antoni Niekraszewicz

Maria Wisniewska-Wrona

Pawel Starostka

Wlodzimierz Mikolajczyk

Gerhard Keunecke

Dariusz Wawro

Arkadiusz Wilczek

Konrad Kazmierski

Ewa Wesolowska

Jan Kazmierski

Stanislaw Galecki

Henryk Struszcyk

Danuta Ciechanska

Karlina Grzebieniak

Magdelena Kucharska

Magdalena Kucharska

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.

Methods of producing modified microcrystalline chitosan and uses therefor

Disclosed is a process for producing particles of the modified carbohydrate polymer chitosan. Such chitosan particles are &ldquo;activated&rdquo; 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.

Process for preparing chitosan particles

A polypropylene composition and modified fibers thereof, includes polypropylene and an elastomer. The elastomer has a melting temperature of, at least, 80&deg; C., preferably 100-180&deg; 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/cm . 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.

Modified fibres and other products from polypropylene and procedures for the manufacture of modified fibres and other products from polypropylene

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.

Process for producing cellulosic mouldings

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.

Method for modified manufacture of cellulose carbamate

Growing community of inventors

Lodz, Poland

Alojzy Urbanowski