Polymer dispersed liquid crystal (PDLC) films were prepared by photopolymerization induced phase separation (PIPS) with living macro-initiator (MI) of different molecular weights

synthesized by RAFT and iniferter polymerization.The effect of molecular weight of MIs on electro-optical properties of PDLC based on graft polymers was investigated.The effects of molecular weight of MIs on morphologies

transmittance

switching voltage and memory effect of PDLC films were studied in detail.It was found that the decrease in the molecular weight of MIs in the films led to the formation of larger liquid crystal droplets.The threshold voltage decreased from 15.9 V to 4.2 V and the off-state transmittance showed an increase tendency

which could be contributed to the increase of liquid crystal droplet diameter.In addition

the saturation voltage also decreased from 36.5 V to 16.4 V while the memory effect increased because of the decreased interface anchoring strength induced by the lower molecular weight of polymer matrix and weaker entanglement that polymer flexible main chain exerted on liquid crystal molecules.Therefore

the decrease decrease of molecular weight of MIs successfully improved the electro-optical properties of PDLC films based on graft polymers.