Terminology

Degradability

This term is used here to denote the susceptibility of polyolefins to the loss of physico-chemical properties as a result of molecular weight reduction owing to oxidation. It’s very slow in the environment for conventional polyolefins but very much more rapid when TDPA™ additives are incorporated in the resins. Heat, UV light, mechanical stress or some combination of these causes the oxidation of plastics in various environments. Testing of specific resin – additive formulations is done by EPI using the accelerated tests and procedures that have been designed by ASTM to simulate exposures in common disposal environments. EPI recommends specific formulations and addition levels to its licensees that are based on the requirements of the application and the results of this testing.

Biodegradability (Aerobic)

This term refers to degradation resulting from susceptibility to the actions of microorganisms. In other words, in the presence of air, microorganisms such as bacteria and fungi consume the material, converting the carbon in part to cell biomass and in part to carbon dioxide, and the hydrogen to water. This set of processes proceeds in the natural environment under many conditions and converts organic materials into soil-improving compost.

Oxo-biodegradation

Oxo-biodegradation may be defined as biodegradation in which polymer chain cleavage is primarily due to oxidation which may be mediated by abiotic chemistry, microorganisms or a combination of both. This is a fancy way of saying that oxo-biodegradable plastics undergo oxidative degradation and their oxidation products biodegrade.

Polyolefins containing TDPA™ additives are oxo-biodegradable plastics.