Electric Field Manipulation of Cellulose Whiskers in Polyvinyl Acetate

Cellulose whiskers as inclusions have shown a lot of promise due to their potential to enhance mechanical and piezoelectric response of polymers. In addition, CWs are high aspect ratio particles; by aligning them in polymers, improved and anisotropic physical properties could be achieved. In this study, we investigate the effect of AC electric field on the alignment of CWs in a solution of PVAc and DMF. CWs were dispersed as small bundles (<10μm). Alignment and chain formation was found to be a function of electric field magnitude, frequency and time. Dielectric constant of the solutions was studied as a function of applied electric field magnitude, frequency and duration. Significant improvements in dielectric constant were observed for the aligned cases as compared to random case. Optimum properties were achieved at 100 – 200 Vpp/mm and 50 KHz for duration of 20 minutes. Future work will focus on processing thin films with individually dispersed CWs, and improving their alignment to further increase the electrical and mechanical properties.