Advancing Sustainability: Geraniol-Enhanced Waterborne Acrylic Pressure-Sensitive Adhesives without Chemical Modification

Materials (Basel). 2024 Oct 10;17(20):4957. doi: 10.3390/ma17204957.

Abstract

The escalating global emphasis on sustainability, coupled with stringent regulatory frameworks, has spurred the quest for environmentally viable alternatives to petroleum-derived materials. Within this context, the adhesives industry has been actively seeking renewable options and eco-friendly synthesis pathways. This study introduces geraniol, a monoterpenoid alcohol, in its unmodified form, as a key component in the production of waterborne pressure-sensitive adhesives (PSAs) based on acrylic latex through emulsion polymerization. Multiple formulations were developed at varying reaction times. The adhesives underwent comprehensive chemical characterization employing techniques such as Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Nuclear Magnetic Resonance (NMR), Gel Permeation Chromatography (GPC), and dynamic light scattering (DLS). The viscosities of the formulations were measured between 4000 and 5000 cP. Adhesion tests showed peel strength values of 0.52 N/mm on cardboard and 0.32 N/mm on painted steel for the geraniol-based formulations. The results demonstrate the potential for geraniol-based PSAs to offer a sustainable alternative to petroleum-derived adhesives, with promising thermal and adhesive properties.

Keywords: acrylic PSA; bio-based adhesive; emulsion polymerization; green copolymers.

Grants and funding

This research acknowledges support from the Project CH4.0 under the MIUR program “Dipar-timento di Eccellenza 2023–2027”. This work has been partially supported by the Spoke 1 “Aerospace and sustainable mobility” of NODES ecosystem, PNRR.