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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: zeoliteguy on November 18, 2018, 08:52:02 AM

Title: Fast Biodegradability test for plastic
Post by: zeoliteguy on November 18, 2018, 08:52:02 AM
Hello,

Is there a test that determines whether a plastic is biodegradable in water or not in a short amount of time? We have this experiment that requires the plastic to decompose for us to see our desired result. (Ive learned that acetone can dissolve plastic fast but Im thinking that it may affect the mineral, zeolite, when mixing with the water and produce different result) .



Why do we need to decompose it?
We are planning to infuse zeolites in a biodegradable plastic so that when the plastic decomposes in the water, the zeolite mixes in it and we're expecting it to clean the water.

**Edit 1: We are planning to use cornstarch biodegrable plastic since we were told that it is easy to make
Title: Re: Fast Biodegradability test for plastic
Post by: Corribus on November 20, 2018, 09:52:57 AM
For one, you are not using the term "biodegradable" correctly. Strictly speaking, biodegradability refers to the degradation (falling apart) of a material induced by, typically, microorganisms (the "bio" part). If water is inducing the chemical changes, this is not biodegradation. We might refer to this as hydrolysis.

Also. Water doesn't necessarily have to degrade the polymer in order to induce changes. Many polymers, including most biopolymers, absorb water (a process known as swelling). This can drastically change the physical properties of the polymer, without actually causing any chemical changes to the polymer backbone. Swelling is not the same thing as dissolution, mind.

So basically, there's a lot of processes and you need to be specific about what you're really looking for.  Only then can we talk about methods to measure whatever process you need to measure.