Turning Polystyrene- a Plastic Waste into Treasure with Sunlight and LEDs

Plastics vary in their recyclability, with certain types and colors being more challenging to recycle than others.

- Monikandon Sukumaran *, Kesavan Devarayan and Ramar Marimuthu

Black foam and black coffee lids often made of polystyrene typically end up in landfills because their color additives hinder proper sorting. Polystyrene is a versatile polymer widely used in packaging, insulation and consumer goods. Despite its utility, polystyrene waste poses a significant environmental challenge due to its non-biodegradability and widespread use. Particularly problematic are black and colored polystyrene, which are difficult to recycle due to their pigmentation and the complexity of sorting processes. Recent advancements in photochemical techniques using sunlight or white light-emitting diodes (LEDs) have opened up pathways for transforming this waste into reusable starting materials presenting a sustainable solution to the growing plastic waste crisis.

Challenges with Black and Colored Polystyrene Recycling Pigmentation and Sorting Difficulties:

Black and colored polystyrene often contain dyes and pigments that hinder traditional recycling methods like infrared detection in sorting facilities. These results in such waste frequently ending up in landfills or being incinerated.

Chemical Stability:

Polystyrene's chemical stability while beneficial for product durability makes it resistant to breakdown under standard environmental conditions.

Environmental Impact:

Improper disposal of polystyrene contributes to pollution and microplastics formation, harming ecosystems and wildlife.

These challenges necessitate innovative recycling methods capable of addressing the limitations of traditional approaches.

Photochemical Degradation of Polystyrene: