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Polymers, long chain molecules built from repeating units, are everywhere in modern life. Plastics for packaging, textiles for clothing, rubber for tires, coatings for surfaces, and specialized polymers in electronics, batteries, and medical devices. These materials offer remarkable properties: lightweight, durable, moldable into complex shapes, and inexpensive to produce. Polymer science has enabled countless technologies over the past 50 years.

However, the same properties that make plastics valuable, their durability and chemical resistance, create serious challenges. Most plastics are derived from fossil fuels, requiring significant energy to produce. They persist in the environment for decades or centuries when discarded, accumulating in landfills, oceans, and ecosystems worldwide. Current recycling approaches are limited: mechanical recycling (melting and remolding) degrades polymer properties with each cycle and works for only a few plastic types, while most plastic waste is incinerated or landfilled. The energy intensity of producing virgin plastics from petroleum, combined with low recycling rates and environmental persistence, makes plastics a significant energy and environmental challenge.

RASEI research addresses these challenges through three complementary approaches: developing better methods to recycle existing plastics, designing new plastics from sustainable sources that decompose more readily, and creating advanced functional polymers for energy applications.

Chemical recycling of existing plastics. Mechanical recycling, the current dominant approach, has fundamental limitations. Heating and remolding plastics breaks polymer chains, degrading properties. Mixed plastics (different types combined) can't be mechanically recycled together. Contamination from food, labels, or additives further limits what can be recycled. As a result, only about 9% of plastic waste globally is recycled, with the rest incinerated or landfilled.

Chemical recycling offers an alternative: using chemical reactions to break plastics back down into their molecular building blocks, which can then be used to make new plastics without property degradation. This process can handle mixed plastic waste, contaminated materials, and plastic types that can't be mechanically recycled. However, current chemical recycling methods often require high temperatures, harsh chemicals, or substantial energy input, in many cases more than making virgin plastic from oil.

RASEI researchers are developing more efficient chemical recycling pathways using bio-catalysis and electrocatalysis. Bio-catalytic approaches use engineered enzymes or microorganisms to selectively break specific polymer bonds under mild conditions, near room temperature, in water, with no harsh chemicals. This dramatically reduces energy requirements compared to thermal or chemical methods. Electrocatalytic recycling uses electricity to drive bond-breaking reactions, allowing control over reaction conditions and the potential to use clean electricity. Both approaches aim to make chemical recycling energy-efficient and economically competitive with virgin plastic production, enabling true circularity where plastic waste becomes feedstock for new plastics.

Sustainable and decomposable plastics. Rather than designing plastics to last forever, RASEI researchers explore plastics engineered for appropriate lifetimes, durable during use but decomposable afterward. This includes plastics derived from sustainable feedstocks rather than petroleum, and polymers designed with chemical bonds that can be broken down intentionally when recycling or disposal is desired.

Bio-based plastics use biological starting materials, such as sugars, starches, cellulose, lignin, or oils from plants, as the building blocks instead of petroleum. This reduces dependence on fossil fuels and can lower production energy if manufacturing processes are efficient. However, "bio-based" doesn't automatically mean "biodegradable", some bio-plastics are chemically identical to petroleum-based versions and equally persistent. RASEI research focuses on developing plastics that are both bio-based and designed for end-of-life decomposition or easy chemical recycling.

Designing for decomposition requires molecular-level control. Polymers can be engineered with specific weak points, essentially chemical bonds that break under certain conditions (enzymes, pH, temperature, light exposure) but remain stable during normal use. This enables plastics that function normally for months or years but decompose when exposed to composting conditions or specific recycling treatments. The challenge is balancing stability during use with decomposability afterward, while maintaining the performance properties that make plastics useful.

Research also addresses the manufacturing side: developing synthetic approaches that efficiently convert bio-based feedstocks into useful polymers using minimal energy and producing minimal waste.

Advanced functional polymers for energy applications. Beyond commodity plastics for packaging and products, specialized polymers enable critical energy technologies. RASEI research develops high-performance polymers for several applications:

Organic semiconductors for solar cells and flexible electronics use conjugated polymers that conduct electricity and absorb light. Unlike rigid silicon-based electronics, polymer semiconductors can be solution-processed, printed onto flexible substrates, and manufactured at lower temperatures, potentially reducing costs. RASEI researchers design new polymer structures with improved charge transport, better light absorption, and enhanced stability, advancing polymer solar cells and organic electronic devices.

Polymer electrolytes for batteries replace liquid electrolytes with solid or gel polymers, improving safety (no flammable liquids), enabling flexible battery designs, and potentially increasing energy density. The challenge is achieving high ion conductivity (so batteries charge/discharge efficiently) while maintaining mechanical strength and electrochemical stability. RASEI work on polymer electrolyte design addresses these competing requirements through molecular engineering and nanostructured architectures.

Membranes for energy conversion include polymer membranes in fuel cells (conducting protons while blocking gases), electrolyzers (separating hydrogen and oxygen production), and batteries (preventing internal short circuits while allowing ion flow). Membrane performance, ionic conductivity, selectivity, stability, directly impacts device efficiency and lifetime. Researchers develop polymers with optimized structures, chemical functionalities that enhance ion transport, and durability under operating conditions.

Improving these functional polymers enhances energy device performance, which reduces energy consumption, having more efficient solar cells generate more electricity from the same sunlight, better battery materials store more energy in smaller/lighter packages, and improved fuel cell membranes convert fuel to electricity more efficiently. Additionally, developing lower-energy manufacturing processes for these advanced polymers reduces production energy demand.

These three research directions share common challenges and approaches. All require molecular-level understanding and design of polymer structure and properties. All need characterization techniques that reveal how polymer structure affects performance. By working across commodity and functional polymers, from recycling to synthesis to device integration, RASEI's polymer research addresses both the environmental challenges of existing plastics and the energy technology opportunities of advanced polymer materials.