Study On The Preparation And Performance Of Polysiloxane Liquid Crystal Elastomer Materials

As stimulus-responsive smart materials,liquid crystal elastomers can be deformed under external stimuli which can be used in microwave detection to measure the microwave intensity in the environment.In this paper,polysiloxane main chain and side chain liquid crystal elastomer films were prepared.By introducing ultrasonic sonochemistry,the polymerization time of the liquid crystal elastomer material was greatly shortened,and the microwave stimulation-response of the liquid crystal elastomer was studied.Based on this,a microwave detection system using liquid crystal elastomer as the actuating material was designed and manufactured.The main research contents are as follows:(1)Three representative diene-terminated liquid crystal monomers were designed and synthesized,and ultrasonic sonochemistry was introduced into the polymerization process of liquid crystal elastomers.Three representative main liquid crystal elastomers were prapared by the polymerization or copolymerization of these three monomers whose mechanism and properties were discussed.Their properties were similar with the same type of elastomers reported.(2)Polysiloxane side-chain liquid crystal elastomers were also prepared by both traditional thermal polymerization and ultrasonic sonochemistry.By compared,the properties of the liquid crystal elastomer prepared by these two methods were similar.The experimental results showed that ultrasonic sonochemistry took a short time,and the performance was not much different from the material prepared by traditional thermal polymerization which greatly reduced the difficulty of preparing the main chain liquid crystal elastomer,greatly improved the yield and efficiency,and could be a path for batch fabrication and low cost.(3)The microwave actuation performance of the side chain liquid crystal elastomer were initially explored,and the dielectric properties and actuation performance of the material under microwave radiation were analyzed.The strong penetration of microwave radiation can easily penetrate the non-metallic opaque barrier to effectively actuate the liquid crystal elastomer material,and can also penetrate multiple liquid crystal elastomer samples and actuate them almost simultaneously.(4)A microwave detection system employed the side chain liquid crystal elastomer film as the actuating material was prepared which has high sensitivity and portable monitoring of microwave radiation intensity.