Hydrophobe Staerkecarbamate und Verfahren zu ihrer Herstellung

Die Erfindung betrifft ein Verfahren zur Herstellung von hydrophoben Carbamaten von Staerke, teilabgebauten Staerken, Dextranen und Dextrinen sowie hydrophoben Staerkecarbamate. Dazu werden Staerken in hochkonzentrierte Staerkenloesungen bzw. stark gequollen mit langkettigen Alkylisocyanaten unter Lewissaeuren Bedingungen umgesetzt. In Abhaengigkeit von Reaktantenverhaeltnis, Gemischverhaeltnis, Reaktionszeit und Durchmischungsintensitaet koennen gezielt Substitutionsgrade zwischen 0,5 bis nahezu 3 eingestellt werden. Verwendung finden diese hydrophoben Staerkecarbamate zur Herstellung von bioabbaubaren Polymeren.

DE 10129312 A UPAB: 20030731 NOVELTY - Optionally protected alkyl isocyanates are used in a method for the production of hydrophobic carbamates of starch, partly-degraded starch, dextran and/or dextrin by adding an isocyanate and a Lewis acid catalyst to a solution of native starch and/or starch products in an isocyanate-inert solvent or swelling agent at 60-160 deg. C. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (a) hydrophobic starch carbamates obtained by this method (operated as a discontinuous process in a horizontal or vertical kneader), with a degree of substitution (DS) of 0.5-3 and a contact angle to water of more than 100 deg. ; and (b) similar products with a DS of 0-2 and a contact angle of more than 95 deg. , obtained by continuous reaction in a twin screw extruder. USE - Hydrophobic starch carbamates obtained by this method are used for the production of biodegradable polymers (claimed). Applications include compatibilisers and coating materials. ADVANTAGE - Enables the production of hydrophobic starch carbamates with a wide range of possible components and reaction conditions and without using environmentally undesirable aromatic isocyanates.