Enhanced Electro-Optical Properties and Peel Strength of Epoxy-Based Polymer-Stabilized Liquid Crystal Films Enabled by Rapid Cationic Polymerization and Polymer-Network Morphology Regulation

Polymer-stabilized liquid crystal (PSLC) dimming film has attracted widespread attention due to its normally transparent state, energy-saving capability, and excellent electro-optical performance, which has promising applications in smart cars and building windows. However, achieving good electro-optical performance and high peel strength simultaneously still remains challenging. In this study, a PSLC film based on monoepoxy and diepoxy monomers was prepared through rapid cationic polymerization, showing low driving voltages and high peel strength simultaneously. The influence of the content and composition of two epoxy monomers on the microstructures, mechanical properties, and electro-optical performance of the PSLC films were systematically studied. The polymer morphology of PSLC could be effectively modulated by doping monoepoxy monomers. The PSLC film with total monomer content of ≤15 wt% showed enhanced electro-optical properties and peel strength when doping monoepoxy monomers due to the lateral polymer in the networks and denser polymer on the substrate. When the ratio of E6M to E6PM was 12:3, compared with pure E6M, the threshold voltage decreased from 18.2 V to 12.6 V, and the peel strength increased from 62.53 kPa to 136.37 kPa. These PSLC films can adapt to the requirements of different application scenarios by changing the content and proportion of two epoxy monomers, and the strategy has good prospects in the actual production and application of PSLC films.