Abstract: Heterophasic compositions comprising starch and a thermoplastic polymer that is incompatible with the starch, in which the starch constitutes the discontinuous phase and the thermoplastic polymer the continuous matrix, having an impact strength greater than 30 KJ/m2 (measured on blown film of 30 microns thick at 10° C. and RH less than 5%), and further characterised by the presence in the X-ray diffraction spectrum of a peak at an angle 2-theta from 13 to 14° the ratio of the intensity of which to that of the peak of the amorphous starch which occurs at 20.5°, is less than 2 and greater than 0.02.

Abstract: Heterophasic compositions comprising starch and a thermoplastic polymer that is incompatible with the starch, in which the starch constitutes the discontinuous phase and the thermoplastic polymer the continuous matrix, having an impact strength greater than 30 KJ/m2 (measured on blown film of 30 microns thick at 10° C. and RH less than 5%), and further characterised by the presence in the X-ray diffraction spectrum of a peak at an angle 2-theta from 13 to 14° the ratio of the intensity of which to that of the peak of the amorphous starch which occurs at 20.5°, is less than 2 and greater than 0.02.

Abstract: Biodegradable foamed articles having density comprised from 5 to 300 kg/m.sup.3 obtained by agglomeration of foamed particles having composition comprising a thermoplastic starchy material or a thermoplastic natural polymer capable of absorbing water when converted into the thermoplastic state, a thermoplastic polymer, and water.

Abstract: Biodegradable foamed plastic material having a bulk density comprised within the range of from 5 to 13 kg/m.sup.3, comprising:30-99.5 by weight of polisaccharide containing more than 50% of thermoplastic starch or starch complexed by polimeric structures, having an intrinsic viscosity (in DMSO) lower than 1.3 dl/g and less than 20% by weight of soluble fraction in ethanol;0.5-70% by weight of a thermoplastic polymer which is soluble in starch, or is capable of complexing it;0-20% by weight of water.The material can be used as a loose filler or for other foamed articles.

Abstract: Biodegradable foamed articles having density comprised from 5 to 300 kg/m.sup.3 obtained by agglomeration of foamed particles having composition comprising a thermoplastic starchy material or a thermoplastic natural polymer capable of absorbing water when converted into the thermoplastic state, a thermoplastic polymer, and water.

Abstract: In order to prepare a starch-based composition usable for the production of articles of biodegradable plastics material, a starch is mixed in a heated extruder with a high-boiling plasticizer and a destructuring agent for a time sufficient to cause the starch to be destructured, in dependence on the destructuring agent used, at a temperature below the boiling point of the plasticizer used and between 120.degree. and 170.degree. C.The composition thus obtained is particularly suitable for the formulation of polymer mixtures with polymers which have relatively high melting points, since it can be processed at temperatures higher than 120.degree. C. and is suitable for extrusion at low pressure with these polymers.

Abstract: The method of producing plasticized polyvinyl alcohol by mixing polyvinyl alcohol in the presence of an organic plasticizer and water in a quantity which is insufficient to dissolve the polyvinyl alcohol under normal conditions, includes the steps of:i) pre-plasticizing the polyvinyl alcohol at a maximum temperature no higher than its softening point so as to produce a pre-plasticized polyvinyl alcohol having a melting point below the softening point of the polyvinyl alcohol used, andii) further processing the pre-plasticized polyvinyl alcohol thus produced at a temperature above its melting point, under shear-stress conditions and for a period of time to produce a substantially homogeneous melt.

Abstract: The film-forming polymeric compositions described include a synthetic, thermoplastic polymer and a starchy material, with a high amylopectin content; they enable the production of films, sheets and the like having good liquid- and gas-barrier effects and improved mechanical properties.

Abstract: In order to prepare a starch-based composition usable for the production of articles of biodegradable plastics material, a starch is mixed in a heated extruder with a high-boiling plasticizer and a destructuring agent for a time sufficient to cause the starch to be destructured, in dependence on the destructuring agent used, at a temperature below the boiling point of the plasticizer used and between 120.degree. and 170.degree. C.The composition thus obtained is particularly suitable for the formulation of polymer mixtures with polymers which have relatively high melting points, since it can be processed at temperatures higher than 120.degree. C. and is suitable for extrusion at low pressure with these polymers.

Abstract: Biodegradable compositions comprising destructured starch and an ethylene-vinyl acetate copolymer are prepared by mixing the starch and the copolymer in an extruder heated to a temperature of between 80.degree. and 180.degree. C. and bringing the water content to below 6% and any ammonia content to below 0.2% by weight. The composition fed to the extruder may optionally include up to 40% by weight of an ethylene-vinyl alcohol polymer, as well as a starch destructuring agent and a high boiling plasticizer.

Abstract: Formed articles comprising destructurized starch, an ethylene-acrylic acid copolymer and a product of the interaction of starch and ethylene-acrylic acid copolymer wherein the starch not bound to the copolymer is in the form of particles having sizes below 1 micron. The water content of such articles is lower than the one usually present in the starch. Said formed articles can also contain urea in an amount no higher than 30% by weight and/or ammonia in an amount not higher than 0.5% by weight. The process for obtaining such articles comprises the steps of extruding starch, an ethylene-acrylic acid copolymer and optionally water, urea and/or ammonia at a temperature ranging from 90.degree. to 150.degree. C., reducing the water content to values lower than 6% by weight and injection molding or extrusion blowing the resulting composition.

Abstract: Process for the continuous manufacture of thermomoldable thermoplastic composite materials comprising feeding simultaneously on a conveyor belt a granulated thermoplastic polymer together with a reinforcement selected from natural, artificial and synthetic fibers, and compacting and heating under pressure the thus-obtained mixture.