Study on the effects of isotropic cross-linked pristine morphology and electro-optical properties of PDLC films

PDLC films were prepared by polymerization-induced phase separation (PIPS) method along with varying composition ratio between curable epoxy monomers/poly-oxy-propylene-di-amine (POPDA) cross-linking agent/Class alpha, longitudinal nematic liquid crystal (LC) linear chain polymer mixtures and their optical and pristine morphological properties have been analyzed to investigate their suitability as aligned nematic phase of LC. The refractive index of isotropic cross-linked polymer network could be influenced by the relative content of curable monomers structure PPGDE 380 and PPGDE 640 which increased the LC droplet size with POPDA. Meanwhile, it is examined that the decreasing of peel strength and transmittance of all the samples decrease of wavelength in the wavelength range of 300-800 nm due to the lower cross-linking density of the polymer network with effect of strongly influenced by the alkoxy (R-O) and flexible chain length of curable monomers, which also affect the electro-optical properties and droplet size of LC in PDLC films. Our results demonstrate that the LC droplet size of the isotropic cross-linked polymer network could be regulated by adjusting the monomers structure, composition ratio, relative wt% of POPDA, PPGDE 380 and PPGDE 640; then aligned nematic phase of LC have the optical properties of uniaxial crystals and their potential applications for PDLC smart glass market and display fields.