No More Soggy Straws

In the United States alone, more than 220 kg of plastic waste is generated per person each year.¹ To address this, several countries have banned single-use plastics, with straws being some of the first items to go because of the specific environmental problem they pose. In the ocean, these small lightweight plastics may be ingested by fish, seabirds, and marine mammals, and they also are prone to breaking down into microplastics and entering the food chain.

Although plastic straw alternatives are becoming more accessible than ever, consumer reactions to these replacements have been mixed. Complaints range from alternative disposables going limp too quickly or tasting bad to reusable straws being hard to clean and inconvenient to carry around. There is also commercial resistance, since going plastic-free may be hard to scale up or present additional costs.

However, making this switch a success could have an impact on the appetite for future moves to more sustainable options for other single-use plastics. This is becoming increasingly important, since a recent OECD report highlighted that we are producing twice as much plastic waste as two decades ago, yet only 9% is successfully recycled. The rest is either burnt or ends up in oceans or landfill, all of which results in environmental harm.¹

Now, a team reporting in ACS Omega has developed a new type of bioplastic straw from potato starch and lignin. Starch is a viable sustainable alternative since it is readily available, cost-effective, safe to consume, biodegradable, microplastic-free, and already used for many products. But starch alone does not make for very successful straw replacement. Likewise, lignin is too brittle to form a straw; however, this natural polymer contains an aromatic ring that allows for the engineering of advanced thermosets with more structurally sound properties. As a common waste product, lignin also ticks the sustainability box.²

The researchers developed all-natural, biocompatible, degradable straws by mixing lignin, citric acid, potato starch, and poly(vinyl alcohol). The resulting product was stronger than plastic and was able to successfully transport liquid without going soggy. Biomaterials such as lignin and keratin are well-known and represent some of the most promising environmentally friendly, functional, and industrially applicable resources. These materials could go beyond just being used for single-use items, with potential applications in short-life electronics, displays, and healthcare devices.³

An important consideration in the hunt for replacements is to ensure that we don’t create a straw man. For example, metal drinking tools will be disposed of less often, but they pose a different set of problems, including a high energy cost for production, damage caused by mining, and almost four times the carbon emissions as compared to plastic counterparts.² Similarly, research has already shown that some straws marketed as biodegradable contain forever chemicals, and plant-based straws have already had to be phased out of use due to per- and polyfluoroalkyl substances (PFAS) used for water resistance.⁴ This creates an entirely new problem, since PFAS break down slowly, and have been implicated in multiple health and environmental effects. Looking for solutions among natural polymers should be the first port of call, and will allow us to begin to make real inroads into the problem of plastic pollution.

Explore Related Research in ACS Journals

Biobased, Degradable, and Conjugated Poly(Azomethine)s
Azalea Uva, Angela Lin, and Helen Tran
DOI: 10.1021/jacs.2c12668

Toward Sustaining Bioplastics: Add a Pinch of Seasoning
Hyeri Kim, Giyoung Shin, Min Jang, Fritjof Nilsson, Minna Hakkarainen, Hyo Jung Kim, Sung Yeon Hwang, Junhyeok Lee, Sung Bae Park, Jeyoung Park, Dongyeop X. Oh, Hyeonyeol Jeon, and Jun Mo Koo
DOI: 10.1021/acssuschemeng.2c06247

Photocatalytic Depolymerization of Native Lignin toward Chemically Recyclable Polymer Networks
Hongyan Wang, Gavin J. Giardino, Rong Chen, Cangjie Yang, Jia Niu, and Dunwei Wang
DOI: 10.1021/acscentsci.2c01257

References

1. Plastic pollution is growing relentlessly as waste management and recycling fall short. The Organisation for Economic Co-operation and Development (OECD).
2. Agumba, D.O. et al. Ultrastrong, Hydrostable, and Degradable Straws Derived from Microplastic-Free Thermoset Films for Sustainable Development. ACS Omega 2023, 8, 8, 7968–7977.
3. Ofondu, A. et al. Lignin and Keratin-Based Materials in Transient Devices and Disposables: Recent Advances Toward Materials and Environmental Sustainability. ACS Omega 2022, 7, 13, 10854–10863.
4. Bourzac K. ‘Biodegradable’ straws contain PFAS. C&EN 2021, 99,11, 5.