Dr Jose Miguel Martín-Martínez
Scientific Consultant, Noxun
Prof. Dr. José Miguel Martín-Martínez is founder and head of the Adhesion and Adhesives Laboratory of the University of Alicante (Spain). Currently, he is Scientific Consultant of Noxun Adhesives Company. He is Editor-in-Chief of Journal of Adhesion Science and Technology and Associate Editor of Rubber Chemistry and Technology journals. He is an expert on the synthesis, formulation and characterization of different adhesives and well-known specialist on Adhesion. He has imparted more than 400 talks at international conferences, and has published 56 books and book chapters and more than 300 papers in the Web of Science database. He was awarded with Robert L. Patrick Fellowship and is a fellow of the American Adhesion Society.
Surface Changes in PSAs with Different Adhesive Thickness/Paper with Unlike Tack
Pressure sensitive adhesives (PSAs) are generally supported on different carriers (paper, polyethylene, polypropylene) for being used in packaging and labelling. Tack is one of the key properties of PSAs and its value is influenced by different experimental parameters, including adhesive thickness, although this has been scarcely addressed. The most few studies carried out to date have been made in acrylic PSAs and they have shown that tack increases by increasing PSA thickness, though some literature evidenced the opposite trend. In this study, the influence of tack (measured by the probe tack method) with the adhesive thickness (50 and 200 μm) of hot melt PSA supported on paper was studied and the variation of tack at 20 ºC with the adhesive thickness was related to the wettability (water and di-iodomethane contact angles) and chemical changes (ATR-IR and Raman spectroscopy) on PSA surface.
The tack at 20 ºC of PSA/paper decreases by increasing the adhesive thickness. For the same adhesive thickness (200 μm), the tack at 20 ºC of PSA/paper decreases significantly with respect to the one of bulk PSA, and the surface energy decreases significantly. On the other hand, the shape of the tack curves at 20 ºC varies with the adhesive thickness, and the maximum displacement becomes larger with the increase in adhesive thickness. These variations can be ascribed to the balance between non-linear variation of the strain rate and the different orientation of the polymer chains located at the probe-PSA and PSA-paper interfaces. In fact, the ATR-IR and, particularly, Raman spectra of PSA/paper with different thicknesses show different intensities of C=O (1242 cm-1) and C-O (1743 cm-1) stretching bands, higher amount of C-H with respect to C=O species, and the formation of new C-H bands for adhesive thickness lower than 100 µm. On the other hand, the polar component of the surface energy of PSA/paper decreases by increasing the adhesive thickness.
Co-authors:
A.D. Galindo-Cegarra, L. Gallego-Reina, E. Jardim, J. Juárez-Molina – All authors belong to Noxun Adhesives Company.
Breakout Session XI – Research Advances in Adhesive Science & Processing – 17 September 2026 – 17:00 – 17:30 – Room Churchill – GF