How come plastic doesn't break down/biodegrade like other stuff???

Answer 1

it does, just slower because it is such an unnatural comosition.

Answer 2

What you call "plastic" is a general/trivial expression for polymers.
You have to see polymers as very long chains built from identical (case of homopolymers) or different (case of heteropolymers) small chemical 'bricks'. Those bricks are called monomers.
Depending on the nature of monomers the resultant polymer have different properties (chemical stability, biodegrability, mechanic resistance, thermal resistance, etc).

A polymer based on the C-C backbone tends to be nonbiodegradable, whereas heteroatom-containing polymer backbones confer biodegradability. Biodegradability can therefore be engineered into polymers by the addition of chemical linkages such as anhydride, ester, or amide bonds, among others. The mechanism for degradation is by hydrolysis or enzymatic cleavage resulting in a scission of the polymer backbone. Macroorganisms can eat and, sometimes, digest polymers, and also initiate a mechanical, chemical, or enzymatic aging.

Nick fury gave a very funny response!
Beside siliconic polymers (which all biodegrade pretty well) all the rest contain a lot of carbon!

Pechorin1... it's just a question of time. Polymers degrade in nature first due to humidity, temperature variations and UV radiation. Once the breaking of chemical links begin... micro-organisms will start feeding with the smaller resulted units. But this can mean 5-30 years!

So...... nothing resists for ever. Especially if it's made by humans :)

Answer 3

Since it does not occur in nature no biological activity attacks it, also it has a very dense molecular arrangement that resists simple dissolution.

Answer 4

it's a non-organic polymer.

there isn't any carbon in it to 'biodegrade'.

Answer 5

it eventually will become brittle and over the years it will break down