Biodegradable thermoplastic polymer blend compositions are presented in which a first polymer and a second polymer are intimately associated together in a uniform, substantially homogeneous blend. The second polymer of the composition acts to facilitate biodegradation of the composition, and of shaped articles manufactured therefrom, at a rate which is enhanced over that of the most slowly biodegrading individual polymer component of the composition. The composition may further comprise a polysaccharide component, such as a starch component like destructurized starch.
RELATED UNITED STATES PATENT APPLICATION
This is a continuation of Ser. No. 08/147,609 filed Nov. 4, 1993, now abandoned which is a continuation-in-part application from commonly assigned co-pending U.S. patent application Ser. No. 08/001,873, filed Jan. 8, 1993, now abandoned.
The present invention relates to a method for modifying articles and/or semi-finished products made from polymer resin moulding compositions, wherein said articles and/or semi-finished products, which substantially consist of moulding compositions comprising mixtures of thermoplastic polymers where exhibit good biodegradability and thermoplastic polymers which exhibit poor biodegradability, are subjected to biodegradation.
An extrudable PVA-containing composition is disclosed, which enables PVA articles to be manufactured on conventional extrusion apparatus. The compositions includes a lubricant, such as a fatty acid amide, most preferably octodecanamide and is most preferably formed into pellets by cold pressing.,The compositions are suitable for manufacturing a variety of products.
The use of zwitterionic compounds as mold release agents in thermoplastics is disclosed. Molding compositions having good release properties, preferably compositions containing polycarbonate resins are thus disclosed.
The present invention is directed to methods of making biodegradable films and biodegradable precursor films having enhanced breathability and ductility. The method includes blending a water soluble polymer and a biodegradable polymer to form a blended polymer mixture. The biodegradable polymer is preferably a biodegradable aliphatic polyester, and the water-soluble polymer is preferably polyethylene oxide and/or polyethylene glycol. The blended polymer mixture is formed into a precursor film. The precursor film is further processed to form a breathable biodegradable film.
A blend of starch and a thermoplastic aliphatic-aromatic copolyester resin, at a specific gravity of greater than 1.0. In method form, the invention comprises supplying an aromatic-aliphatic based polyester, supplying starch and mixing the aromatic-aliphatic based polyester with the starch and introducing the mixture to a melt processing apparatus wherein the aromatic-aliphatic based polyester and starch are mixed and molded or extruded into a desired shape.
