Thermoplasticized starch component and process for the preparation thereof

PCT No. PCT/FI96/00402 Sec. 371 Date Jan. 12, 1998 Sec. 102(e) Date Jan. 12, 1998 PCT Filed Jul. 10, 1996 PCT Pub. No. WO97/03120 PCT Pub. Date Jan. 30, 1997The invention relates to a process for thermoplasticizing starch, a melt-processible polymer composition, which contains a starch-based component and a thermoplastisized polymer component, and a method for preparating such a composition. According to the invention the starch component, which contains hydroxyl groups capable of reacting with isocyanate groups, is modified so that it can be dissolved or gelatinized/plastisized in the melt of a hydroxy acid polymer. The starch component is then reacted with a thermoplastic component formed by a hydroxy acid polymer, in particular a lactic acid polymer, in order to produce a melt-processible, biologically degradable starch-based polymer, which can be used as an adhesive and for coating of paper and cardboard products and for preparation of injection moulded and thermoformed articles.