How do we break down polyethylene

Experiment: "Plastic Decomposition"

In this experiment we examined the chemical decomposition of plastic with organic and inorganic chemicals.

These are examples of the most common types of plastic.

Polyethylene: bottles, handkerchief packaging
Polypropylene: food packaging
Polyvinyl chloride (PVC): hoses, seals
Polystyrene: yogurt cups, styrofoam
Polyurethane (PU / PUR): sponges
Polyethylene terephthalate (PET): bottles, writing foils
Microplastics: peeling beads

Chemical tests

1. Seal

Gasoline, cyclohexane, acetone (→ only the surface reacted and took on a milky haze), ethanol

2. tights (nylon)

Sulfuric acid (inorganic chemical), acetic acid (organic chemical), gasoline, cyclohexane, acetone, ethanol

Sulfuric acid → first the color was extracted and then the fibers came off:

3. Hose

Sulfuric acid (→ bubble formation on the surface), acetic acid, gasoline, cyclohexane, acetone, ethanol

4. Yogurt pots

Sulfuric acid, acetic acid, gasoline, cyclohexane, acetone, ethanol
→ no change

5. Plastic bag

Sulfuric acid, acetic acid, gasoline, cyclohexane, acetone, ethanol
→ no change

6. Package tape

Sulfuric acid, acetic acid, gasoline, cyclohexane, acetone, ethanol
→ no change

7. balloon

Sulfuric acid, acetic acid, gasoline, cyclohexane, acetone, ethanol

Sulfuric acid → color extraction:

Cyclohexane → rolled up and rolled up again a short time later

8. Peeling pellets

Sulfuric acid, acetic acid, gasoline, cyclohexane, acetone, ethanol
→ no change

9. Plastic toys

Sulfuric acid, acetic acid, gasoline, cyclohexane, acetone, ethanol
→ no change

After the weekend...

tube

Cyclohexane → glue came off → division into two parts

Sulfuric acid → color extraction

balloon

Cyclohexane → color extraction

Acetic acid → color extraction

Parcel tape

Sulfuric acid → color extraction

Yogurt pots

Gasoline → curled up and color extraction

Cyclohexane → plastic contracted and color extraction

Acetone → plastic contracted and color extraction

Result of the experiment

It is impossible to break down everyday plastic with organic chemicals from the school laboratory. Our plastic is a combination of different types of plastic and that makes it even more difficult to decompose. It is an extremely resistant material and the experiment was intended to show how difficult it is to destroy plastic. Only the inorganic chemical sulfuric acid, which is a highly corrosive substance, achieved minimal success.

Author: Laura Thalmeier
Experiment carried out by Anna-Lena Stierstorfer & Laura Thalmeier