Sticky tape from wood scraps, the science behind adhesives reimagined
The first thing you might look for while wrapping up a package is probably an adhesive. No wonder, fixing things requires the magic of glue. However, the conventional glue sticks are made up of petroleum-derived materials and we should always think of an alternative sustainable solution. The question is what can be a good replacement? Recently a team of researchers from the University of Delaware has developed a novel method to derive sticky tapes out of a tree component that generally paper manufacturers throw away, called lignin. Moreover, the research outcome produces a competent result in comparison with commercially available products.
As the publication suggests, lignin is a renewable resource, a substance in trees that make them stronger. However, one doesn't need to cut down trees to get them since paper industries already treat them as wastes. Some of the companies also offer it for free since its cheaper than dumping it off in a landfill. In chemical composition, lignin is a natural polymer that shares similar structural and materials properties of petroleum-derived polymers, such as polystyrene and polymethyl methacrylate, used in different packaging industries.
Thomas H. Epps, III, Professor of Materials Science and Engineering at UD always had a question in mind and that was if lignin could be upcycled to produce cheap adhesives with equal strength, toughness, and scratch resistance to the petroleum-based counterpart.
It is not a direct process, as mentioned in the same report, before turning lignin into a product it was first broken down in the Catalysis Center for Energy Innovation (CCEI). Although the organization had perfected methods to process wood components, cellulose, and, hemicellulose, into a useful product, lignin was certainly a challenge since it is a solid part of the biomass, the hardest to break down.
Taking help of the commercially available catalyst, the team developed a mild, low-temperature process that busts the lignin into molecular fragments also known as depolymerization. Once broken, it was converted to synthesize new materials. Upon testing it was found that the greener tape shows similar performance as of Fisherbrand labeling tape and Scotch Magic Tape.
The current research used poplar wood to extract lignin but the team wants to explore more options. A little less or more sticker product can be produced from a different variant of wood. The applications of processed lignin can also be expanded to rubber bands, o-rings, gaskets, and seals, or car tires. The collaborative work has been published in the ACS Central Science.
Source: ACS publications