Understanding chemical transport in polymer composites is important for optimizing performance in several applications including improved chemical resistance of protective coatings. The transport properties at the particle-polymer interface can differ significantly from those in the polymer bulk, and when the interfacial regions overlap, undesirable fast chemical transport pathways can emerge. Improving the performance of composite systems requires a detailed understanding of how the particle interface can be tuned to improve the near-interface transport properties. Colloidal force spectroscopy using atomic force microscopy (AFM) was used to quantify the polymer-particle interaction strength ex-situ at the scale of a single particle in the composite system. Cross-sectioned composites using cryo-microtoming were also studied with amplitude modulation-frequency modulation (AM-FM) AFM and force modulation imaging. In this work, the influence of different particle surface modifications, including chemical functionalization and polymer grafting were assessed using the AFM-based techniques and corresponding changes in transport properties were measured using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Results are presented for silica and surface modified silica particles with a polyurethane polymer in the presence of a vapor penetrant and the changes in adhesion force and interfacial properties are correlated to observed changes in penetrant transport rate in the composite.

Influence of particle polymer interface adhesion on chemical transport in polymer composites

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.