Researchers are determining the lifespan of commercial oceanside straws and developing a prototype bioplastic straw that decomposes faster than paper. WHOI research has shown that some biodegradable straws break down by up to 50% in the marine environment within 16 weeks, providing a sustainable alternative to traditional plastics and helping reduce ocean pollution.

Straw is one of the most common types of plastic litter polluting the beach. As the production, consumption and disposal of plastic products increases, scientists and manufacturers are developing alternative materials that work just as efficiently without contributing to ongoing plastic pollution in the environment.

But not all plastics are created equal; Different manufacturers have different compositions of base polymers and chemical additives, such as polylactic acid (PLA) and polypropylene (PP). This means that different compositions of plastic behave differently in the environment and break down at different rates in the ocean. New materials originating from petroleum-derived products, such as cellulose diacetate (CDA), a polymer derived from wood pulp commonly used in consumer products, are being introduced to the market and scientists at Woods Hole Oceanographic Institution (WHOI) are working on this topic. IT . To measure the lifespan of various plastic products in the environment to answer the unresolved question of how long can straws last in the ocean?

Straw degradation tests and results

In a new article published in ACS Sustainable Chemistry and Engineering WHOI scientists Colleen Ward, Brian James, Chris Reddy and Yanchen Sun compared different types of plastic and paper straws to see which degraded fastest in the coastal ocean. . They collaborated with scientists from bioplastics company Eastman, who funded the research, contributed as co-authors, and provided materials.

“We don’t have a clear understanding of how long plastics stay in the ocean, so we are developing methods to measure the rate at which these materials decompose,” Ward said. “In this case, it turns out there were some bioplastic straws that degraded pretty quickly, which is good news.”

Promising developments in the field of biodegradable straw

Their approach involved suspending eight different types of reeds in a tank filled with constantly flowing seawater from Martha’s Vineyard Sound, Massachusetts. This method also controls temperature, light and other environmental variables to mimic the natural marine environment. Over the course of 16 weeks, all straws were checked for signs of decomposition and the microbial communities growing on the straws were characterized.

“I was interested in understanding the fate, sustainability and toxicity of plastic and how we can use this knowledge to develop next-generation materials that are better for people and the planet,” James said. “We have a unique opportunity to bring the ocean environment onto land in our tanks in the Environmental Systems Laboratory. “This gives us a highly controlled environment with natural seawater.”

They tested straws made of CDA, polyhydroxyalkanoates (PHA), paper, PLA and PP. CDA, PHA and paper straws degrade up to 50% within weeks of immersion in the tanks, and their lifespan in the coastal ocean environment is estimated to be 10-20 months. PLA and PP straws showed no measurable signs of degradation.

Environmental impact of straw materials

The researchers then compared two straws made of CDA (one solid and one foam), both supplied by Eastman. Straws made from foamed CDA were prototyped to see whether increasing the surface area would speed up disintegration. They found that the decomposition rate of the foam was 184% faster than its solid counterpart, resulting in a shorter predicted lifespan in the environment than paper straws.

“What’s unique about this foam straw is that it can have a shorter life expectancy than paper straws, but still retains the properties you get from a plastic or bioplastic straw,” James said, making it a promising alternative to traditional plastic straws. . Compared to paper straws, which degrade quickly in the ocean, the authors say they become soggy, negatively affecting the user experience.

Industry and environmental prospects

“This research could be extremely valuable to straw manufacturers as it provides informed and transparent data when choosing straw material. Moreover, it provides confidence that CDA-based straws will not contribute to ongoing plastic pollution and demonstrates straw manufacturers’ commitment to providing an environmentally friendly product that reduces the risk to marine life.” It shows,” said Jeff Carbeck, Eastman’s vice president of corporate affairs. questions Innovation.

The constant struggle of plastic

Science supports the rejection of traditional plastic materials. Plastic pollution harms people and ecosystems, and the plastic industry is a significant contributor to climate change, accounting for approximately 4 to 5% of all lifetime greenhouse gas emissions. As plastic waste has become ubiquitous in the world’s oceans and the marine food chain over the last 50 years, it is important to identify new materials that are environmentally friendly resources, contribute to the transition from a linear economy to a circular economy, and can be degraded if accidentally broken down. is released into the environment.

“While some are eager to get rid of plastic, the reality is plastic is here to stay. We’re trying to accept the fact that these materials will be used by consumers, and then we can work with companies to minimize their impact if they end up in the environment,” Ward said.

Collaboration for sustainable solutions

“We recognize the importance of testing, validating and understanding the marine degradation of our CDA-based products, but the necessary resources are lacking,” Karbek said. “Knowing that WHOI has sufficient knowledge and equipment, we worked together to tackle this problem. “This partnership demonstrates the power of industry and academia working together to advance common goals and create positive impact.”

The research team also found that the microbial communities in decaying straws were specific to each straw material. However, the microbial communities on both nondisintegrating pipettes were similar despite having very different chemical structures. This provided further evidence that local microbes broke down biodegradable straws, while non-biodegradable straws likely remained in the ocean.

“Our understanding of the impact of plastic pollution on ocean health is really unclear, and a lot of that comes from not knowing the long-term fate of these materials,” Ward said. He and the rest of his research team plan to continue measuring the degradability of plastic materials in hopes of determining where the industry goes next.

“There are many benefits to partnering with materials manufacturers, including access to analytical facilities and information and materials that you may not be able to get if you work in your own shelter,” Ward said. “We are trying to optimize their products for environmental degradation and ultimately for the good of the planet.”

Key findings

• Not all plastics are created equal, and some last longer in the ocean than others. WHOI scientists have spent years measuring the lifespan of various plastics in the environment to determine which ones have the shortest and longest lives in the ocean. To determine what plastic is stored in the ocean, the team tests different products in large tanks that mimic the natural ocean environment. They initially focused on straws because they are one of the most common types of plastic waste found in beach cleanups.
• The authors found that straws made from cellulose diacetate (CDA), polyhydroxyalkanoates (PHA), and paper decomposed 50% in 16 weeks. They all had unique microbial communities that helped break down the material.
• Eastman’s prototype straw, made of foamed CDA, decomposed faster than solid straw, meaning that changing the surface area of ​​the straw could speed up the decomposition process.
• Science supports the move away from sustainable plastics, making it even more important to ensure that new materials break down when released into the environment and do not pollute the ocean.