Adhesion strength and viscoelastic properties of polydimethylsiloxane (PDMS) based elastomeric nanocomposites with embedded electrospun nanofibers

In the present study, the adhesive and viscoelastic properties of polydimethylsiloxane (PDMS) based nanocomposite pressure sensitive adhesives (PSAs) with embedded electrospun polyacrylonitrile (PAN) and polyvinyl alcohol (PVA) nanofibers as fillers were investigated. PDMS nanocomposite adhesive films using PAN and PVA nanofibers were synthesized by dispersing fillers in the matrix by a solvent mixing process. The adhesion strength and reusability of the prepared nanocomposite PSA films were measured using peel tests as the fraction of nanofibers in the polymer matrix is increased. The variations of the adhesive properties of the PSAs as function of the type and loading of filler were related to their rheological properties in terms of shear and elastic moduli. Although 3-fold enhancement of the adhesion strength was achieved with 0.5 wt% loading for both types (PAN and PVA) of nanocomposites as compared to elastic PDMS, the composite adhesive with PAN nanofibers can provide a superior balance of rheological properties, resulting in improved reusability over other PSAs. The differences in the adhesion and viscoelastic properties of the composite PSAs are attributed to the polymer chemistry, processability, and architecture of the electrospun nanofibers in the soft PDMS matrix.