Thermoplastic starch compositions that include a particulate filler, e.g. an inorganic filler component, and optional fibrous component. The compositions include a thermoplastic phase comprising a thermoplastic starch melt that contains, at a minimum, starch blended with an appropriate plasticizing agent under conditions in order for the starch to form a thermoplastic melt. The thermoplastic phase may also include one or more additional thermoplastic polymers and other optional reactants, liquids or cross-linking agents to improve the water-resistance, strength, and/or other mechanical properties of the thermoplastic melt, particularly upon solidification. The inorganic filler component may affect the mechanical properties but will mainly be added to reduce the cost of the thermoplastic starch compositions by displacing a significant portion of the more expensive starch or starch/polymer melt. Fibers may optionally be included in order to improve the mechanical properties of the thermoplastic starch compositions. The thermoplastic starch compositions may be shaped into a wide variety of useful article, such as sheets, films, containers, and packaging materials. Because the thermoplastic starch compositions will typically include a thermoplastic phase that is biodegradable, and because the other components will either constitute a naturally occurring mineral and optionally a natural fiber, the overall composition will typically be more environmentally friendly compared to conventional thermoplastic materials.

Thermoplastic starch compositions incorporating a particulate filler component

Biodegradable polymer blends suitable for laminate coatings, wraps and other packaging materials manufactured from at least one 'hard' biopolymer and at least one 'soft' biopolymer. 'Hard' biopolymers tend to be more brittle and rigid and typically have a glass transition temperature greater than about 10 °C. 'Soft' biopolymers tend to be more flexible and pliable and typically have a glass transition temperature less than about 0 °C. While hard and soft polymers each posses certain intrinsic benefits, certain blends of hard and soft polymers have been discovered which possess synergistic properties superior to those of either hard or soft polymers by themselves. Biodegradable polymers include polyesters, polyesteramides and thermoplastically processable starch. The polymer blends may optionally include an inorganic filler. Films and sheets made from the polymer blends may be textured so as to increase the bulk hand feel. Wraps will typically be manufactured so as to have good 'dead-fold' properties so as to remain in a wrapped position and not spring back to an 'unwrapped' and planar form. Laminate films will typically have good water vapor barrier properties as measured by their Water Vapor Permeability Coefficient (WVPC).

Biodegradable polymer films and sheets suitable for use as laminate coatings as well as wraps and other packaging materials

A biologically degradable polymer mixture contains at least one starch biopolymer made from renewable raw materials, a plasticizer, and a polymer selected from the following materials: an aromatic polyester; a polyester-copolymer with both aliphatic and aromatic blocks; a polyesteramide; a polyglycol; a polyester urethane; and/or mixtures of these components.

Biologically degradable polymer mixture

Biodegradable polymer blends suitable for laminate coatings, wraps and other packaging materials are manufactured from a blend of suitable biodegradable polymers, such as at least one “hard” biopolymer and at least one “soft” biopolymer. “Hard” biopolymers tend to be more brittle and rigid and typically have a glass transition temperature greater than about 10° C. “Soft” biopolymers tend to be more flexible and pliable and typically have a glass transition temperature less than about 0° C. While hard and soft polymers each possess certain intrinsic benefits, certain blends of hard and soft polymers have been discovered which possess synergistic properties superior to those of either hard or soft polymers by themselves. Biodegradable polymers include polyesters, polyesteramides, polyesterurethanes, thermoplastic starch, and other natural polymers. The polymer blends may optionally include an inorganic filler. Films and sheets made from the polymer blends may be textured so as to increase the bulk hand feel. Wraps will typically be manufactured to have good “dead-fold” properties so as to remain in a wrapped position and not spring back to an “unwrapped” form.

Biodegradable polymer blends for use in making films, sheets and other articles of manufacture

A biologically degradable polymer mixture is proposed which consists essentially of starch and at least one hydrophobic polymer. The hydrophobic polymer is in this connection at least substantially biologically degradable and thermoplastically processable and the mixture with the starch comprising a polymer phase mediator or a macromolecular dispersing agent so that the starch is present in the mixture as disperse phase with the hydrophobic polymer as continuous phase, and the phase mediator or the dispersing agent is responsible for the molecular coupling of the two phases. As starch there is preferably used thermoplastic starch which has been prepared substantially with the exclusion of water by means of sorbitol or glycerol. The production of the biologically degradable polymer mixture is also carried out substantially with the exclusion of water.

In order to produce a polymer mixture essentially consisting of starch and a polyolefine, up to 70 wt %. of thermoplastically processable starch is mixed with 10 to 40 wt %. polyolefine and 10 to 35 wt %. ethylene acrylate maleic anhydride copolymer. During this mixing process an esterification reaction takes place between the maleic anhydride groups in the copolymer with free hydroxyl groups in the starch according to the general reaction process (I).

Polymer mixture for producing foils

Fur die Herstellung einer Polymermischung, im wesentlichen bestehend aus Starke und einem Polyolefin, werden bis zu 70 Gew.- % thermoplastisch verarbeitbare Starke zusammen mit 10 Gew.- % bis 40 Gew.- % Polyolefin und 10 Gew.- % bis 35 Gew.- % von Ethylen-Acrylat-Maleinsaureanhydrid-Copolymer gemischt. Bei diesem Mischvorgang erfolgt eine Veresterungsreaktion der Maleinsaureanhydrid-Gruppen im Copolymeren mit freien Hydroxyl-Gruppen in der Starke gemass dem allgemeinen Reaktionsablauf (I).

Tomka Ivan

Papers

Polymer mixture for producing foils

Polymermischung für die herstellung von folien