Polystyrene -> Styrene

Bucky Gerson

ARCH 5500: Processing the Anthropocene

How can we make polystyrene into a more rigid building material, while reducing the volume that it takes up in landfills in the end of life stage?

Polystyrene

Early forms of polystyrene were created in the mid 1800's, but it wasn't until 1954 when EPS as we know it today was created. The first shipment of styrofoam cups shipped in 1960.

Polystyrene is one of the most popular plastics used today. It comes in three forms:

(1) Sheets and molded polystyrene

(2) Expanded polystyrene (EPS)

(3) Extruded polystyrene (XPS)

Almost 16 million metric tons is produced every year.

Production Process

1. Crude Oil

2. Petroleum Refining

3. Benzene Production

4. Styrene Production

5. Polystyrene Production

6. Shaping of Polystyrene Using Steam

End of Life

Polystyrene is considered non-biodegradable and takes 500 years to decompose. Since polystyrene is comprised of petroleum, it does have properties that make it technically recyclable. But EPS is also comprised of more than 90% air, which makes it lightweight and bulky. These properties mean the collection and transportation impacts of recycling EPS often outweigh the environmental benefits.1

By turning polystyrene back into styrene its life can be prolonged, it can be kept out of landfills and can prevent chemicals and micro plastics from leaching into the water supply.

Polystyrene to Styrene

Estimated Time

Active Time: 15 - 20 minutes

Drying Time: 1 - 7 Days

Ingredients:

Polystyrene

Acetone or D-Limonene

Equipment:

Plastic Coated Paper Bowls or Plates

Stir Sticks

Face Masks

Eye Protection

Rubber Gloves

Silicone Mold

Recipe:

Step 1: Prepare work space, adorn PPE, have mold close by.

Step 2: Place polystyrene in/on bowl or plate. Break into small pieces if necessary to fit.

Step 3: Pour acetone or d-limonene onto foam. Watch it disappear.

Step 4: Using stirring stick, stir mixture until homogeneous.

Step 5: Add more polystyrene until mixture is relatively thick (similar to maple syrup--real not fake syrup).

Step 6: Continue to mix and add until mixture reaches desired consistency.

Step 7: Pour mixture into mold or onto flat covered surface.

Step 8: Wait until mixture dries (from one day up to a week). Please note, the processes of breaking polystyrene into styrene releases a lot of a air. If the mixture is being dried flat, it will need to be pressed down every once in a while. Maximum airflow is recommended.****

*The white packing foam works best, but colorful insulation foam works too and dyes the end product.

**Wood works best. Cannot use plastic.

***Or silicone mat or parchment paper or whatever else you want to use as a cast--that is not plastic.

****This may require removing it from the mold once it is dry enough to keep its shape. Acetone dries very quickly, which means the outside of the final product will dry much quicker than the interior.