Dairy discovery

PLATTEVILLE, Wis. — In 2020, the world was upended by the coronavirus pandemic. In dairy circles, challenges included farms dumping milk. However, Dr. Joseph Wu and Dr. John Obielodan of the University of Wisconsin-Platteville saw an opportunity.

“We saw the waste, and we thought: there is a protein in milk that could be useful,” Obielodan said. “Some of the characteristics are similar to the characteristics we’ve seen in some plastic materials.”

After years of researching how to create plastic from lignin found in plants, the two professors recognized a chance to create 3D printed plastic from the proteins found in spoiled milk. 

They pivoted their study from lignin, a plant-based polymer, to dairy in 2021. With help from the Dairy Innovation Hub and the University of Wisconsin System, the professors discovered how to turn dairy into plastic. The researchers began working with spoiled milk, turning waste into a useful product. They were awarded a U.S. patent earlier this year.

“Anywhere there is waste, either in the process of making a product, or when there is spoiled milk available in any scenario, it can be collected,” Obielodan said. “We wanted to take that milk and use it to extract the proteins inside for something that could be of benefit. This is an opportunity that can be grasped by the industry. Rather than waste material, it can be useful for something else.”

Wu elaborated on the chemistry that begins the process of creating the plastic.

“Right now dairy is only for consumption, but if you lower the pH of milk, you can collect the protein,” Wu said. “The proteins are biopolymers because we have this carbon chain and we can harvest it. You can do some treatment to eliminate an undesirable component and change the functional group. Once I purify it into pure milk protein, I pass it along to John.”

From there, Obielodan and his students searched for the correct parameters to discover what would create a new plastic.

“We convert it into useful products and determine the methodologies that will be right and the parameters that will make it work well on the machine,” Obielodan said. “It takes us a good deal of time to figure out what parameters are going to make it work in any of the processes that we are working on.” 

3D printed plastics are not the final goal for the project but were the best way to test the new theory. Spoiled milk is not a necessity in the process, but to avoid supply chain disruptions and economic factors, the professors deemed it the best material for the study compared to fresh milk. 

“Before 3D printing, it was difficult to try out new materials,” Obielodan said. “There are properties that you see, or the behaviors of materials that you see, that indicate this can be good for the traditional process, or injection molding. 3D printing allowed us the chance to test our process first.”

Wu explained what it meant to create a biodegradable plastic from an organic material.

“We proved that the protein can mix with the polymer and then someone can take this concept and make commercial plastic products,” Wu said. “We didn’t know how well it was going to blend with the polylactic acid or polyamine. We have a new material, and we wanted to see how it blended. That was the challenge for this project.”

UW-Platteville had machines on hand to help with some aspects of the project from past studies, but it was still missing a key piece to the project. Dairy Innovation Hub played a key role in the study, providing the funding for a Selective Laser Sintering machine. SLS machines are advanced 3D printing devices that use a laser to fuse powdered materials into solid structures, making the project viable.

“We leveraged our earlier success in converting biopolymers from trees into plastics,”  Obielodan said. “And used it as part of the argument for why we strongly thought this was going to be successful like our lignin trials were. We were lucky to receive the funding to try the idea.”

By testing the process and discovering its viability, Obielodan and Wu have created a new way to create plastic with or without the use of petroleum products.

“We want to advocate for renewable sources of materials that can be used to compete with the petroleum-based materials,” Obielodan said.

 Wu emphasized the importance of using a product that is readily available in his locality. 

“We want to do our part to help the community,” he said. “We are living in a state that depends a lot on the dairy industry. This is also a showcase for our students. We are practicing what we teach. That will be very powerful, and that’s why I tell my students to pay attention in chemistry class.”

Since being awarded the patent, Obielodan and Wu have been working with WiSys to find interested investors who would be willing to continue the work. The professors hope to bring the technology to commercialization.