Plant-Based Plastic That Dissolves in Water Could Redefine Sustainable Packaging

A new plant-based plastic developed by researchers at Japan’s RIKEN Center for Emergent Matter Science dissolves completely in water within just a few hours — leaving no microplastics or residue behind. Built from cellulose, one of the most abundant natural materials on Earth, the innovation points toward a future where packaging no longer becomes permanent pollution.

How This Plant-Based Plastic Works

The newly developed plant-based plastic is built using carboxymethyl cellulose, a polymer derived from wood pulp that is already approved for food and medical use. To bind the cellulose into a solid material, researchers introduced a positively charged compound based on guanidinium ions.

When mixed in water at room temperature, the oppositely charged components attract each other, forming a stable plastic. Crucially, those same bonds can be reversed. When exposed to salt water, the material slowly breaks apart, allowing the plastic to dissolve naturally over time — particularly relevant for ocean environments.

From Brittle Material to Flexible Packaging

Early versions of the plant-based plastic were too rigid, behaving more like glass than usable packaging. To solve this, the research team experimented with plasticizers — small molecules that influence flexibility.

They ultimately selected choline chloride, a compound already approved as a food additive. By adjusting its concentration, the researchers could precisely control the material’s behavior:

• rigid and shape-holding

• stretchable beyond its original length

• thin, transparent film

This tunability allows the same base formula to adapt to multiple packaging needs without changing materials.

Designed for Manufacturing and Recycling

Unlike many experimental materials, this plant-based plastic was developed with real-world production in mind. It remains transparent, can be processed using standard plastic-manufacturing methods, and supports limited recycling before final dissolution.

Because all ingredients are common, approved, and widely available, the transition from laboratory research to industrial application could be significantly faster than with most biodegradable plastics.

A Step Toward Reducing Plastic Pollution

The researchers are clear that this plant-based plastic will not replace all synthetic plastics. Instead, it offers a targeted solution for applications where plastic waste is most harmful — particularly single-use packaging and materials that frequently end up in the ocean.

By redesigning material behavior at the molecular level, the project demonstrates how sustainability can be embedded directly into material structure, rather than added later through disposal systems.

Written by Otávio Santiago, a designer shaping narratives through motion, graphics, and 3D form. His approach merges emotion and precision to craft timeless visual identities and experiences.