Researchers have created a strong adhesive polymer that surpasses existing commercial options and is also biodegradable, adjustable, and reusable. Their research highlights how the naturally occurring polymer P3HB can be chemically modified to serve as a robust and environmentally friendly bonding agent.
Researchers from Colorado State University, along with their collaborators, have invented a new adhesive polymer that is more robust than currently available commercial materials and is also biodegradable and reusable. Their research, published in Science, reveals how the prevalent natural polymer P3HB can be chemically enhanced to function as a durable yet eco-friendly bonding solution.
Adhesives play a crucial role in various sectors, including automotive, packaging, electronics, solar energy, and construction, among others. The adhesive industry is valued at approximately $50 billion, contributing significantly to modern society while also exacerbating the problem of plastic waste. The paper details the team’s experimental and modeling efforts to create a replacement polymer.
The project was spearheaded by University Distinguished Professor Eugene Chen from the Department of Chemistry. Other contributors include Gregg Beckham from the National Renewable Energy Laboratory and Professor Ting Xu from the University of California, Berkeley, along with researchers from their teams.
According to Chen, poly(3-hydroxybutyrate), or P3HB, is a natural, bio-based, and biodegradable polymer that can be synthesized by microbes under suitable biological conditions. Although this polymer doesn’t possess adhesive properties in its natural state, his team successfully chemically altered its structure to provide superior adhesion compared to conventional petroleum-based, non-biodegradable adhesives when applied to various materials like aluminum, glass, and wood. Furthermore, the adhesion strength of the modified P3HB can be adjusted to meet diverse application requirements.
These findings are part of Chen’s broader objective to address the global plastic pollution challenge. His team is engaged in multiple initiatives to develop chemically recyclable, biodegradable, and more sustainable alternatives to current plastic materials. Chen pointed out that while people are usually aware of the environmental issues surrounding disposable water bottles, adhesives present more complex challenges with limited solutions.
“Adhesives made from petroleum, such as Gorilla Glue and J-B Weld, as well as thermoplastic hot melts, are often hard or even impossible to recycle or recover due to their strong bonds with other materials,” he explained. “Our approach features a biodegradable alternative that can be utilized across various industries, offering adjustable or even superior strength compared to traditional products.”
Ph.D. student Ethan Quinn at CSU co-led the research with postdoctoral researcher Zhen Zhang. Quinn mentioned that he and Zhang were instrumental in developing and testing the new material.
“We created a sample P3HB glue stick and successfully tested it with a commercially available glue gun for sealing cardboard boxes and other applications on steel surfaces,” Quinn explained. “I was aware that the data suggested it was stronger than existing products, but I was amazed to find that it vastly outperformed typical hot-melt adhesives, holding up to 20 pounds compared to 15 pounds for a conventional adhesive that failed.”
Chen emphasized that P3HB can decompose in multiple scenarios, including both managed and unmanaged environments. This means it will naturally break down in landfills as effectively as it would in salty ocean water or soil, expanding the options for how to handle the material at the end of its life. The P3HB adhesive can also be retrieved, reprocessed, and reused.
The CSU team is now focusing on commercializing the polymer for widespread use.
“We are pursuing two distinct strategies for mass production, focusing on reducing both costs and environmental impact,” Chen mentioned. “The NREL team’s analysis has highlighted crucial areas for enhancement, and we will continue collaborating with the BOTTLE Consortium to scale up our efforts.”
