Acrylamide-modified polyvinyl alcohol and combined with graphene oxide for low dielectric constant composite films

High transparency, low dielectric, and robustness in polymeric materials have been targeted performance in high-frequency communication applications for the field of smart wearable electric devices. In terms of transparency property, polyvinyl alcohol (PVA) possesses great potential as optical electric material, due to its excellent optical transmission, low cost, and chemical resistance. However, the dielectric property of PVA is confined by abundant polar groups such as hydroxyl groups in the structure. Improving the PVA dielectric performances from the structure is still a great challenge. Herein, we propose a novel structure optimization approach by designing a Michael addition reaction between PVA and acrylamide (AM) to decrease its polar segments and to develop high transparency and low dielectric loss graphene oxide (GO)/PVA-AM composite film. a small content of AM has little effect on the regularity of PVA chains, which increases the chain entanglement between PVA-AM and eventually improves the strength. Meanwhile, the low dipoles (i.e., introducing C-C and CH groups) can distinctly reduce its dielectric constant. Besides, the addition of a certain amount of GO further enhances the strength of the film. Tensile strength of 142.47 MPa, dielectric constant as low as 3.49, and dielectric loss of only 0.055 were achieved, which is superior to those of pure PVA and PVA/GO composite films reported by previous literature. It has great potential in the field of dielectric materials for high-frequency communication.