how do you get plastic oxidized ? I know putting it in the sun will but is there a faster way ? thanks .
You can expose them to bacterial or fungal enzymes. That is an extremely broad category and they are likely to have some effect under certain circumstances. You can expose it to a strong oxidizer like ozone. Some would form from lightning strikes. It would probably take hundreds of years to seriously degrade some plastic that way. Some plastic would be seriously affected by some powerful chemical oxidizer. It would be unusual to find natural oxidizers more active unless you include the ionizing effects of UV light on the oxidizer itself. It may become a free radical and become far more reactive. Most of that would probably involve making compounds that are soluble in water so chemicals are leached away.
