Technical

A study of polythene film containing TDPA (Totally Degradable Plastic Additive) made by EPI (Environmental Plastics Incorporated) conducted at the University of Pisa, Italy has proved that not only does the additve cause the plastic to oxidize and become brittle and weak but it also allows the plastic to be converted into its basic minerals by the enqymic action of microbes.

Emo Chiellini, Andrea Corti and Graham Swift reported that when placed in an air oven at 55C there was a "fast decrease of the films integrity after 11 days of incubation as a result of the fragmentation of the polymer chain".

The fragmented pieces of plastic were then investigated fortheir potential biodegradation in a soil burial test carried out using the biometer flask procedure.

This defines the level of biodegradation taking place by the amount of carbon dioxide given off by the biodegradation process.

The study found LDPE-TDPA oxidized samples undergo significant biodegradation (50 - 60% by carbon dioxide evolution) over a period of 18 months.

When drawn as a graph, the positive slope profiles of the CO2 generation curves indicated that the biodegradation process would continue after the conclusion of the tests.

The study concluded that it is clear that LDPE-PA formulations are effective in promoting the oxidation and subsequent biodegradation of
polytheylene in soil environments.