COMPLEX STARCH-CONTAINING COMPOSITIONS EXHIBITING HIGH MECHANICAL PROPERTIES Russian patent published in 2003 - IPC

FIELD: polymers. SUBSTANCE: invention relates to heterophaseous polymeric compositions showing high stability against ageing under condition of low temperature and humidity. Composition contains starch, 30-90 wt.-% of thermoplastic polymer as measured to starch mass that is incompatible with starch and plasticizing agent. Starch forms the disperse phase and thermoplastic polymer forms the continuous phase. Impact viscosity of indicated composition is above 30 kJ/m². Roentgen spectrum of composition shows peak at angle 2 θ in the limits 13-14^° wherein intensity ratio with respect to peak intensity of amorphous starch that is evident at angle 2θ 20,5^° is less 2 but above 0.02 and characterized by the presence band with wavelength 947 cm^-1 in its spectrum of the second derivative of IR-spectroscopy with Fourier-transformation. Composition can contain water in the amount less 5% and it is prepared by extrusion at value of specific extrusion 0.1-0.5 kWt x h. Extruder augers show reverse profile by above 30% of auger length. Composition is used for making films, sheets, bags, laminates, casting articles, profiles, foamed sheets, thermomolded articles, frothed materials. Invention provides the enhancement of mechanical properties of products, in particular, impact viscosity and tearing resistance and to enhance resistance against ageing under condition of low humidity. EFFECT: valuable properties of compositions. 19 cl, 2 dwg, 5 tbl, 7 ex