Surface Modification of Polyesters Using Biosourced Soil-Release Polymers

Soil-release polymers (SRPs) are important components of fabric care formulations, performing important roles in the cleaning of synthetic fabrics. SRPs modify the surface of textiles and render materials resistant to staining, while offering environmental benefits by enabling effective cleaning using shorter, cooler wash cycles. Most SRPs used in formulations contain petroleum-sourced terephthalic acid, limiting the environmental benefits presented by the use of these key additives. Here, we have prepared SRPs using a selection of pyridine dicarboxylate monomers that can be accessed from biomass and assessed their ability to modify polyester surfaces. Interestingly, a wide range of surface deposition behavior was observed, with soil-release performance significantly impacted by the pyridine dicarboxylate component in use. The performance of polymers containing 2,5-pyridine dicarboxylate units exceeded or was comparable to that of current industry-standard SRPs, while polymers constructed using 2,4- or 2,6-pyridine dicarboxylate units displayed poor performance. Through a range of studies including dynamic light scattering, contact angle analysis, scanning electron microscopy, and molecular modeling we have explored the solution and interfacial behavior of SRPs and propose the observed changes in performance to arise from a combination of differences in solution self-assembly and variation in affinities for polyester surfaces. Our work highlights the potential of using biosourced starting materials in the replacement of petroleum-derived polymers within formulated consumer products and presents a rationale for the design of SRPs.