BonLab Blog
Thoughts & Scientific Fiction
Water-based pressure sensitive adhesives (PSAs) are typically made by emulsion polymerization using a low glass transition temperature base monomer, such as n-butyl acrylate or 2-ethyl hexylacrylate, together with a range of functional comonomers. Typically these include a high glass transition temperature comonomer, such as styrene or methyl methacrylate and monomers that can promote wetting and undergo secondary interactions such as (meth)acrylic acid.
Single-layer graphene is interesting as a flexible 2D material, with xy-dimensions variable up to a centimetre in length and a z-thickness of a single carbon atom. It conducts heat and electricity, has excellent mechanical strength, and is impermeable to gases except hydrogen gas. Its drawback: how to disperse it in a liquid. When you try to do this flexible sheets of graphene tend to stack as a result of attractive van der Waals interactions, making it virtually an impossible material to disperse as single sheets.
Labels are big business. A typical label has multiple layers: a topcoat for protection, the face stock, which contains the message in the form of text and/or images, a pressure-sensitive adhesive, and a release liner, which often has a release coating. The release liner and coating are only there to protect the label from sticking to things you do not wish it would stick to. You remove the liner when you wish to apply the label onto your substrate of choice, for example, a bottle containing a drink.
Imagine a label without a release liner and coating, imagine a label that could be activated at the moment you want it to stick to a substrate, a stick-on-demand linerless label.
BonLab has designed and developed a concept and prototype for a sustainable solution: a mesh reinforced pressure-sensitive adhesive for linerless label design. The idea was worked out by Emily Brogden and prof. dr. ir. Stefan Bon, in collaboration with UPM Raflatac Oy, a global supplier of label materials for branding and promotion, information and functional labelling (patent application: WO2023105120A1). The complete study, which was done at the University of Warwick, is now published in the new journal RSC Applied Polymers.
