| abstract |
Biodegradable film comprises at least one layer comprising water-swellable water-insoluble biodegradable cellulose and/or cellulose acetate and at least one layer comprising crystalline or crystallisable microbiologically produced polyhydroxyalkanoate. Preferably the polyhydroxyalkanoate is R-poly-3-hydroxybutyrate or a copolymer thereof containing 3-20 mol percent of 3-hydroxybutyrate, balance 3-hydroxyvalerate. Composite film may be made by laying the polyhydroxyalkanoate sides of two films together and heat sealing them together. |