An incidental discovery in a wood products lab at Oregon State University has produced a new pressure-sensitive adhesive that may revolutionize the tape industry—an environmentally benign product that works well and costs much less than existing adhesives based on petrochemicals.
The new adhesive can be produced from a range of vegetable oils. Potential applications include almost any type of tape, label or other product requiring a pressure-sensitive adhesive. Pressure-sensitive products now number in the thousands—a $26 billion global industry.
The discovery was made essentially by accident while OSU scientists were looking for something that could be used in a wood-based composite product—an application that would require the adhesive to be solid at room temperature and melt at elevated temperatures.
For that, the new product was a failure.
‘Stop Right There’
“We were working towards a hot-melt composite adhesive that was based on inexpensive and environmentally friendly vegetable oils,” said Kaichang Li, a professor of wood science and engineering in the OSU College of Forestry. “But what we were coming up with was no good for that purpose; it wouldn’t work.”
“Then I noticed that at one stage of our process, this compound was a very sticky resin,” Li said. “I told my postdoctoral research associate, Anlong Li, to stop right there. We put some on a piece of paper, pressed it together and it stuck very well—a strong adhesive.”
Shifting gears, the two researchers then worked to develop a pressure-sensitive adhesive, the type used on many forms of tape, labels and other adhesive products.
“It’s really pretty amazing,” said Li, 2007 recipient of the Presidential Green Chemistry Challenge Award from the Environmental Protection Agency.
“This adhesive is incredibly simple to make, doesn’t use any organic solvents or toxic chemicals, and is based on vegetable oils that would be completely renewable—not petrochemicals. It should be about half the cost of existing technologies and appears to work just as well.”
There have been previous attempts to make pressure-sensitive adhesives from vegetable oils, Li said, but they used the same type of polymerization chemistry as the acrylate-based petrochemicals now used to make tape. They didn’t cost much less or perform as well, he said.
Li’s approach is based on a different type of polymerization process and produces pressure-sensitive adhesives that could be adapted for a wide range of uses, perform well, cost much less, and would be made from soybeans, canola oil, corn or other renewable crops.
Development and Commercialization
The technology should be fairly easy to scale-up and commercialize, Li said.
“OSU has applied for a patent on this technology, and we’re looking right now for the appropriate development and commercialization partner,” said Denis Sather, licensing associate with the OSU Office of Technology Transfer.
“We believe this innovation has the potential to replace current pressure-sensitive adhesives with a more environmentally friendly formulation at a competitive price."